Consumer medicine information

Stemzine

Prochlorperazine maleate

BRAND INFORMATION

Brand name

Stemzine

Active ingredient

Prochlorperazine maleate

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Stemzine.

SUMMARY CMI

Stemzine®

Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

1. Why am I using Stemzine?

Stemzine contains the active ingredient prochlorperazine. Stemzine is used to treat nausea, vomiting and dizziness due to various causes, including migraine (severe headache). For more information, see Section 1. Why am I using Stemzine? in the full CMI.

2. What should I know before I use Stemzine?

Do not use if you have ever had an allergic reaction to prochlorperazine or any of the ingredients listed at the end of the CMI. Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding. For more information, see Section 2. What should I know before I use Stemzine? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with Stemzine and affect how it works. A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use Stemzine?

  • For adults, the usual recommended dose for nausea and vomiting is 1 or 2 tablets two to three times daily. The usual recommended dose for dizziness is 1 or 2 tablets three to four times daily.

More instructions can be found in Section 4. How do I use Stemzine? in the full CMI.

5. What should I know while using Stemzine?

Things you should do
  • Remind any doctor, dentist or pharmacist you visit that you are using Stemzine.
  • Call your doctor straight away if you notice any uncontrolled movements of the tongue, face, mouth or jaw, such as puffing of the cheeks, puckering of the mouth or chewing movements.
Things you should not do
  • Do not stop using this medicine suddenly or reduce the dosage, even if you are feeling better, without checking with your doctor first.
  • Do not take any medicines that cause drowsiness while you are taking Stemzine.
Driving or using machines
  • Be careful before you drive or use any machines or tools until you know how Stemzine affects you.
  • Stemzine may cause dizziness, light-headedness, tiredness, drowsiness in some people.
Drinking alcohol
  • Tell your doctor if you drink alcohol.
  • Be careful when drinking alcohol while taking Stemzine.
Looking after your medicine
  • Keep Stemzine in a cool, dry place. Protect from light.
  • Keep Stemzine where young children cannot reach it.

For more information, see Section 5. What should I know while using Stemzine? in the full CMI.

6. Are there any side effects?

Less serious side effects include constipation, dry mouth, drowsiness, restlessness, trembling, rigid posture, mask-like face, slow movements and a shuffling unbalanced walk, uncontrollable twitching, jerking or writhing movements, blurred vision, and low blood pressure. Serious side effects include unusual muscle tone or spasms causing distortion of the body in children, a sudden increase in body temperature, extremely high blood pressure and severe convulsions, shortness of breath, wheezing, difficulty in breathing or swallowing, swelling of the face, lips, tongue or other parts of the body, and a rash, itching or hives on the skin. If you experience any of these serious side effects, go straight to the Emergency Department at your nearest hospital. For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.



FULL CMI

Stemzine®

Active ingredient: prochlorperazine


Consumer Medicine Information (CMI)

This leaflet provides important information about using Stemzine. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using Stemzine.

Where to find information in this leaflet:

1. Why am I using Stemzine?
2. What should I know before I use Stemzine?
3. What if I am taking other medicines?
4. How do I use Stemzine?
5. What should I know while using Stemzine?
6. Are there any side effects?
7. Product details

1. Why am I using Stemzine?

Stemzine contains the active ingredient prochlorperazine. Stemzine belongs to a group of medicines called phenothiazines.

It helps to correct chemical imbalances in the brain, allowing it to function correctly.

These chemicals may also affect the parts of the brain which control nausea (feeling sick) and vomiting.

Stemzine is used to treat nausea, vomiting and dizziness due to various causes, including migraine (severe headache).

Your doctor may have prescribed Stemzine for another reason. Ask your doctor if you have any questions about why Stemzine has been prescribed for you.

2. What should I know before I use Stemzine?

Warnings

Do not use Stemzine if:

  • you are allergic to prochlorperazine, the group of medicines called phenothiazines, or any of the ingredients listed at the end of this leaflet.
  • Always check the ingredients to make sure you can use this medicine.
  • you have any of the following medical conditions:
    - shock
    - disease of the blood with a low number of blood cells
    - yellowing of the skin and/or eye, also called jaundice

Stemzine must not be given to anyone who is unconscious or in a coma.

Check with your doctor if you:

  • you have allergies to any other medicines or any other substances, such as foods, preservatives or dyes.
  • have any other medical conditions, especially the following:
    - phaechromocytoma, a rare tumour of the adrenal glands which sit near the kidneys
    - Parkinson's disease, a disease of the brain affecting movement which causes trembling, rigid posture, slow movement and a shuffling, unbalanced walk
    - myasthenia gravis, a disease of the muscles causing drooping eyelids, double vision, difficulty in speaking and swallowing and sometimes muscle weakness in the arms or legs
    - kidney problems
    - heart and blood vessel problems, low blood pressure
    - blood clots
    - liver disease
    - prostate problems
    - bowel problems
    - epilepsy, seizures or fits
    - low blood calcium levels
    - decreased thyroid activity
    - glaucoma, a condition in which there is usually a build-up of fluid in the eye
    - neuroleptic malignant syndrome, a reaction to some medicines with a sudden increase in body temperature, extremely high blood pressure and severe convulsions
    - a reaction to some medicines with uncontrollable twitching or jerking movements of the arms and legs
    - dementia
    - diabetes
    - a low number of white blood cells
    - symptoms of Reye's syndrome in children such as diarrhoea, rapid breathing, vomiting and severe fatigue
    - chicken pox or measles in children
    - dehydration in children

If you have not told your doctor or pharmacist about any of the above, tell them before you start taking Stemzine.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Use in children

Do not use in children less than 2 years of age or weighing less than 10 kg.

Pregnancy and breastfeeding

Use of Stemzine is not recommended during pregnancy.

Check with your doctor if you are a woman of childbearing age and not using effective contraception, or if you are pregnant, might become pregnant or think you may be pregnant. If there is a need to take Stemzine during your pregnancy, your doctor will discuss with you the benefits and risks of using it.

Use of Stemzine is not recommended during breastfeeding. If you are breastfeeding or planning to breastfeed, talk to your doctor about using Stemzine.

It is recommended that you do not breastfeed while taking Stemzine, as it is not known whether Stemzine passes into breast milk.

3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Stemzine and affect how it works. These include:

  • some medicines used to control depression or mood swings or mental illness such as lithium
  • medicines metabolised by CYP2D6 enzymes such as amitriptyline
  • alcohol
  • desferrioxamine, a drug used in iron overdose
  • medicines used for cancer such as procarbazine
  • some medicines used to control epilepsy such as phenobarbital and carbamazepine
  • antibiotics used to treat infections
  • medicines used to treat Parkinson's disease such as levodopa
  • medicines used for the treatment of diabetes
  • anticholinergic medicines which are used to relieve stomach cramps, spasms and travel sickness
  • atropine, a medicine which may be used in some eye drops or cough and cold preparations
  • some oral medicines used to prevent your blood from clotting
  • medicines used to treat high blood pressure or heart problems such as clonidine, guanethidine and propranolol
  • medicines used to treat fluid build-up in your body
  • medicines used to treat a fast or irregular heart beat e.g. amiodarone, quinidine, disopyramide.
  • medicines that can slow your heart beat e.g. diltiazem, verapamil.
  • medicines that can reduce potassium levels in the blood e.g. diuretics, laxatives.
  • other medicines that can affect your heart rate e.g. methadone, pentamidine.
  • antacids containing magnesium, aluminium and calcium salts, oxides and hydroxides
  • adrenaline used for severe allergic reactions
  • amfetamine

These medicines may be affected by Stemzine or may affect how well it works. You may need different amounts of your medicine or you may need to take different medicines. Your doctor will advise you.

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Stemzine.

4. How do I use Stemzine?

How much to use

Your doctor or pharmacist will tell you how much Stemzine you will need to take each day. This depends on your condition and whether or not you are taking any other medicines.

  • The usual recommended dose for nausea and vomiting is 1 or 2 tablets two to three times daily.
  • The usual recommended dose for dizziness is 1 or 2 tablets three to four times daily.
  • Follow the instructions provided and use Stemzine until your doctor tells you to stop.

When to use Stemzine

  • It does not matter if you take Stemzine before or after food.

How to use Stemzine

  • Swallow Stemzine tablets whole with a full glass of water.
  • Do not chew the tablets.

If you use too much Stemzine

If you think that you have used too much Stemzine, you may need urgent medical attention.

Do not try to vomit.

You should immediately:

  • phone the Poisons Information Centre
    (by calling 13 11 26), or
  • contact your doctor, or
  • go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

Your doctor or pharmacist has information on how to recognise and treat an overdose. Ask your doctor or pharmacist if you have any concerns.

5. What should I know while using Stemzine?

Things you should do

  • Tell any other doctors, dentists and pharmacists who are treating you that you are taking Stemzine.
  • If you are about to be started on any new medicines, tell your doctor, dentist or pharmacist that you are taking Stemzine.
  • If you plan to have surgery that needs a general anaesthetic, tell your doctor or dentist that you are taking Stemzine.

Call your doctor straight away if you:

  • notice any uncontrolled movements of the tongue, face, mouth or jaw, such as puffing of the cheeks, puckering of the mouth or chewing movements. These are symptoms of a very rare condition called tardive dyskinesia, which may develop in people taking phenothiazine medicines, including Stemzine. The condition is more likely to occur during long term treatment with Stemzine, especially in elderly women. In very rare cases, this may be permanent.
  • become pregnant while taking Stemzine.

Things you should not do

  • Do not give Stemzine to anyone else, even if they have the same condition as you.
  • Do not take Stemzine to treat any other complaints unless your doctor or pharmacist tells you to.
  • Do not stop taking Stemzine, or lower the dosage, even if you are feeling better, without checking with your doctor.
  • Do not stop taking Stemzine suddenly. If you do, your condition may worsen or your chance of getting an unwanted side effect may increase. To prevent this, your doctor may gradually reduce the amount of Stemzine you take each day before stopping completely.
  • Do not take any medicines that cause drowsiness while you are taking Stemzine.

Sun exposure

  • Stemzine may cause your skin to be much more sensitive to sunlight than it is normally. It is advised to avoid exposure to direct sunlight during treatment.
  • If outdoors, wear protective clothing and use at least a 15+ sunscreen.
  • Exposure to sunlight may cause a skin rash, itching, redness, or severe sunburn. If your skin does appear to be burning, tell your doctor.
  • Make sure you keep cool in hot weather and keep warm in cool weather. Stemzine may affect the way your body reacts to temperature changes.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Stemzine affects you.

Stemzine may cause drowsiness, dizziness, and blurred vision. If this occurs do not drive.

If Stemzine makes you feel light-headed, dizzy or faint, be careful when getting up from a sitting or lying position. Getting up slowly may help.

Drinking alcohol

Tell your doctor if you drink alcohol.

Be careful when drinking alcohol while taking Stemzine.

If you drink alcohol, dizziness, drowsiness or light-headedness may be worse.

Your doctor may suggest you avoid alcohol while you are being treated with Stemzine.

Looking after your medicine

  • Keep Stemzine in a cool dry place where the temperature stays below 30°C. Protect from light.
  • Keep your Stemzine in the pack until it is time to take them. If you take the tablets out of the pack, they may not keep well.

Store your Stemzine tablets in a cool dry place away from moisture, heat or sunlight; for example, do not store it:

  • in the bathroom or near a sink, or
  • in the car or on window sills.

Keep it where young children cannot reach it.

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, take it to any pharmacy for safe disposal.

6. Are there any side effects?

All medicines can have side effects. Stemzine helps most people with nausea, vomiting and dizziness, but it may have unwanted side effects in a few people. If you are over 65 years or age you may have an increased chance of getting side effects.

If you do experience any side effects, do not stop taking Stemzine without first talking to your doctor or pharmacist. Most side effects are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Less serious side effects

Less serious side effectsWhat to do
Gastrointestinal or gut related:
  • constipation
  • dry mouth
Central nervous system related:
  • drowsiness
  • restlessness
  • trembling, rigid posture, mask-like face, slow movements and a shuffling unbalanced walk
  • uncontrollable twitching, jerking or writhing movements
Vision or eye related:
  • blurred vision
Cardiovascular or heart related:
  • low blood pressure
The following side effects are less common:
  • changes in heart beats
  • swelling of the hands, ankles or feet
  • skin rash
  • for females: unusual secretion of breast milk, irregular or stopping of periods
  • for males: breast enlargement, difficulty in ejaculating, getting or maintaining an erection, or persistent painful erection
  • severe pain in the stomach with bloating, cramps and vomiting
  • difficulty passing urine
  • yellowing of the skin and/or eyes
  • headache
  • insomnia
  • seizures
  • agitation
  • dizziness
  • difficulty in breathing
  • brownish deposits in the eyes
  • stuffy nose
Speak to your doctor if you have any of these less serious side effects and they worry you.

Serious side effects

Serious side effectsWhat to do

Allergic reaction related (that can occur either immediately or within several days of drug administration) that may be life-threatening):

  • shortness of breath, wheezing or difficulty in breathing or swallowing
  • swelling of the face, lips, throat, tongue or other parts of the body
  • cold, clammy skin, palpitations, dizziness, weakness or fainting
  • rash, itching or hives on the skin
Musculoskeletal related:
  • unusual muscle tone or spasms causing distortion of the body in children
General:
  • sudden increase in body temperature, extremely high blood pressure and severe convulsions.
  • hypersensitivity, fever, rash, facial swelling, swollen lymph nodes (which could be symptoms relating to raised levels of infection fighting cells (relating to eosinophilia)
Nervous system related:
  • high fever, muscle cramps or stiffness, dizziness, severe headache, fast heartbeat, confusion, agitation, hallucinations, or are sweating a lot (symptoms relating to Neuroleptic malignant syndrome)
Liver related:
  • yellowing of the skin and/or eyes (jaundice) and urine becomes darker in color
Blood related:
  • bleeding and bruising (thrombocytopenic purpura).
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these side effects. These are very serious side effects. You may need urgent medical attention or hospitalisation.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems. By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

7. Product details

This medicine is only available with a doctor's prescription.

What Stemzine contains

Active ingredient
(main ingredient)
prochlorperazine maleate 5mg
Other ingredients
(inactive ingredients)
wheat starch
calcium hydrogen phosphate dihydrate
magnesium stearate
sodium lauryl sulfate

Do not take this medicine if you are allergic to any of these ingredients.

What Stemzine looks like

Stemzine tablets are white, round and marked with "S". Tablets are available in packs of 25 (AUST R 67940).

Who distributes Stemzine

Stemzine is supplied in Australia by:

sanofi-aventis australia pty ltd
12-24 Talavera Road
Macquarie Park NSW 2113
Toll Free Number (medical information): 1800 818 806
Email: [email protected]

This leaflet was prepared in October 2023.

stem-ccdsv6-cmiv16-04oct23

Published by MIMS November 2023

BRAND INFORMATION

Brand name

Stemzine

Active ingredient

Prochlorperazine maleate

Schedule

S4

 

1 Name of Medicine

Prochlorperazine maleate.

2 Qualitative and Quantitative Composition

Stemzine contains 5 mg prochlorperazine maleate as the active ingredient.

Excipients of known effect.

Gluten.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Stemzine 5 mg tablets are off-white to pale cream coloured circular tablets, not more than slightly mottled or specked, one side impressed with 'S' and reverse face plain.

4 Clinical Particulars

4.1 Therapeutic Indications

Nausea and vomiting due to various causes including migraine; vertigo due to Meniere's syndrome, labyrinthitis and other causes.

4.2 Dose and Method of Administration

Nausea and vomiting.

Adults. Dosage should be adjusted to suit the response of the individual, beginning with lowest recommended dosage.

Oral.

5 or 10 mg two or three times daily.

Acute.

20 mg at once, followed, if necessary, by 10 mg two hours later.
Children. (See Section 4.3 Contraindications; Section 4.4 Special Warnings and Precautions for Use, Paediatric use.)
Prochlorperazine is not recommended for children under 2 years of age or weighing less than 10 kg.
If it is considered unavoidable to use prochlorperazine for a child, the dosage is 250 micrograms/kg bodyweight two or three times a day.
Prochlorperazine has been associated with dystonic reactions particularly after a cumulative dosage of 500 micrograms/kg. It should therefore be used cautiously in children.
When treating children, it is recommended that the 5 mg tablets are used.
Occasionally the patient may react to the drug with signs of restlessness and excitement; if this occurs, treatment should be discontinued.

Vertigo and Meniere's disease.

Adults.

Oral.

5 to 10 mg three or four times daily.
Dosage may be reduced gradually after several weeks to a maintenance dosage of 5 to 10 mg daily.
Children.

Oral.

Dose same as for nausea and vomiting.
Geriatric. In general, dosages in the lower range are sufficient for most elderly patients. Since they are especially susceptible to hypotension and extrapyramidal reactions, such patients should be observed closely. Dosage should be increased more gradually in elderly patients.

Impaired liver function.

Since prochlorperazine is extensively metabolised by the liver, dosage reduction may be necessary.

4.3 Contraindications

Circulatory collapse, central nervous system depression (coma or drug intoxication with alcohol, barbiturates, narcotics etc.), previous history of a hypersensitivity reaction (e.g. jaundice or blood dyscrasia) to phenothiazines especially to prochlorperazine, bone marrow depression.
Hypersensitivity to prochlorperazine, other phenothiazines, or to any of the other ingredients listed in Section 6.1.
In children, due to a possible association between use of phenothiazine-containing products and sudden infant death syndrome (SIDS).
Do not use in paediatric surgery.
Do not use in children for conditions for which dosage has not been established.

4.4 Special Warnings and Precautions for Use

Hypersensitivity reactions including anaphylactic reaction, urticaria and angioedema have been reported with Stemzine use. In case of allergic reaction, treatment with Stemzine must be discontinued and appropriate symptomatic treatment initiated (see Section 4.8 Adverse Effects (Undesirable Effects)).
Prochlorperazine should be avoided in patients with liver or renal dysfunction, Parkinson's disease, hypothyroidism, cardiac failure, phaeochromocytoma, myasthenia gravis and prostate hypertrophy. It should be avoided in patients with a history of narrow angle glaucoma or agranulocytosis.
Acute withdrawal symptoms, including nausea, vomiting, headache, anxiety, agitation, dyskinesia, dystonia, disturbed temperature regulation, and insomnia, have very rarely been reported following the abrupt cessation of high doses of neuroleptics. Relapse may also occur, and the emergence of extrapyramidal reactions has been reported. Therefore, gradual withdrawal is advisable. Symptoms of withdrawal can occur following treatment at any dose. Withdrawal of treatment should occur under close medical supervision.
As agranulocytosis has been reported, regular monitoring of the complete blood count is recommended. The occurrence of unexplained infections or fever may be evidence of blood dyscrasia and requires immediate haematological investigation.
All patients should be advised that, if they experience fever, sore throat or any other infection, they should inform their physician immediately and undergo a complete blood count. Treatment should be discontinued if any marked changes (hyperleucocytosis, granulocytopenia) are observed in the blood count.
As with all antipsychotic drugs, Stemzine should not be used alone where depression is predominant. However, it may be combined with antidepressant therapy to treat those conditions in which depression and psychosis coexist.
Prochlorperazine can cause photosensitisation, therefore patients should be advised to avoid exposure to direct sunlight during treatment.
To prevent skin sensitisation in those frequently handling preparations of phenothiazines, the greatest care must be taken to avoid contact of the drug with the skin (see Section 4.8 Adverse Effects (Undesirable Effects)).
In schizophrenia, the response to prochlorperazine treatment may be delayed. If treatment is withdrawn, the reoccurrence of symptoms may not become apparent for some time. Avoid concomitant treatment with other neuroleptics.
Phenothiazines may be additive with, or may potentiate the action of, other CNS depressants such as opiates or other analgesics, barbiturates or other sedatives, general anesthetics, or alcohol.

Stroke.

In randomised clinical trials versus placebo performed in a population with elderly patients with dementia and treated with certain atypical antipsychotic drugs, a 3-fold increase of the risk of cerebrovascular events has been observed. The mechanism of such risk increase is not known. An increase in the risk with other antipsychotic drugs or other populations of patients cannot be excluded. Stemzine should be used with caution with stroke risk factors.

Hypotension.

The autonomic side effects of the piperazine derivatives are less troublesome than those of other phenothiazines, however care should be taken if prochlorperazine is used in the elderly or in patients undergoing surgery with spinal anaesthesia.

Epileptics.

Close monitoring is required in patients with epilepsy or a history of seizures, as phenothiazines may lower the seizure threshold. The occurrence of convulsive seizures necessitates the discontinuation of the treatment.
Piperazine derivatives are also less epileptogenic than other phenothiazines, but care should still be exercised in epileptic patients.

Anticholinergic effects.

Prochlorperazine can cause problems due to anticholinergic effects, especially in the elderly (urinary difficulties, constipation and precipitation of acute narrow angle glaucoma), but to a lesser extent than with other phenothiazines.

Hypocalcaemia.

It appears from a study of 5 hypocalcaemic patients with hypoparathyroidism that such patients are prone to acute dystonic reactions with prochlorperazine.

Sedative effect.

Prochlorperazine may impair mental and physical activity especially during the first few days of therapy. Patients should be warned about activities requiring alertness.

Antiemetic effects.

The antiemetic effects of prochlorperazine may mask signs of overdosage of toxic drugs or obscure the diagnosis of conditions such as intestinal obstruction, brain tumour.

Reye's syndrome.

The extrapyramidal symptoms which can occur secondary to prochlorperazine may be confused with the central nervous system signs of an undiagnosed primary disease responsible for the vomiting, e.g. Reye's syndrome or other encephalopathy. The use of prochlorperazine and other potential hepatotoxins should be avoided in children and adolescents whose signs and symptoms suggest Reye's syndrome.

Hypothermia.

Severe hypothermia may occur during swimming in cold water or in patients receiving antipyretic therapy.

Tardive dyskinesia.

Tardive dyskinesia may develop in patients on antipsychotic drugs. The disorder consists of repetitive involuntary movements of the tongue, face, mouth or jaw (e.g. protrusion of the tongue, puffing the cheeks, puckering of the mouth, chewing movements). The trunk and limbs are less frequently involved. It has been reported that fine vermicular movements of the tongue may be an early sign of the syndrome.
Both the risk of developing the syndrome and the likelihood that it will become irreversible are believed to increase as the duration of treatment and the total cumulative dose of the drug increases. Less commonly, the syndrome can develop after relatively brief treatment periods at low doses. The risk seems to be greater in elderly patients, especially females.
The syndrome may become clinically recognisable either during treatment, upon dosage reduction, or upon withdrawal of treatment. The dosage of antipsychotic drug should be reduced periodically (if clinically possible) and the patient observed for signs of the disorder, since the syndrome may be masked by a higher dose. In patients requiring long-term treatment, the smallest dose and the shortest duration of treatment producing a satisfactory clinical response should be sought.
There is no known effective treatment for tardive dyskinesia. Antiparkinsonian agents usually do not alleviate symptoms. It is suggested that antipsychotic agents be discontinued if symptoms of tardive dyskinesia appear.

Neuroleptic malignant syndrome.

A potentially fatal syndrome called neuroleptic malignant syndrome has been reported in association with antipsychotic drugs. The syndrome is characterised by muscular rigidity, fever, hyperthermia, altered consciousness and autonomic instability (e.g. tachycardia, labile blood pressure, profuse sweating, dyspnoea).
It is imperative that prochlorperazine treatment be discontinued in the event of unexplained fever, as this may be a sign of neuroleptic malignant syndrome (pallor, hyperthermia, autonomic dysfunction, altered consciousness, muscle rigidity).
Signs of autonomic dysfunction, such as sweating and blood pressure instability, may precede the onset of hyperthermia and serve as early warning signs.
Although neuroleptic malignant syndrome may be idiosyncratic in origin, dehydration and organic brain disease are predisposing factors (see Section 4.8 Adverse Effects (Undesirable Effects)). The management of neuroleptic malignant syndrome should include immediate discontinuation of anti-psychotic drugs, intensive monitoring and treatment of symptoms, and treatment of any associated medical problems.

QT interval.

Very rare cases of QT interval prolongation have been reported with prochlorperazine. Neuroleptic phenothiazines may potentiate QT interval prolongation which increases the risk of onset of serious ventricular arrhythmias of the torsade de pointes type, which is potentially fatal (sudden death).
QT prolongation is exacerbated, in particular, in the presence of bradycardia, hypokalemia and congenital or acquired (i.e. drug induced) QT prolongation. If the clinical situation permits, medical and laboratory evaluations should be performed to rule out possible risk factors before initiating treatment with a neuroleptic agent and as deemed necessary during treatment (see Section 4.8 Adverse Effects (Undesirable Effects)).

Cerebrovascular events.

An increased risk of cerebrovascular events has been reported in elderly patients with dementia treated with atypical antipsychotic drugs. An increase in the risk of cerebrovascular events with other antipsychotic drugs or other populations of patients cannot be excluded. Prochlorperazine should therefore be used with caution in patients with stroke risk factors.

Thromboembolism.

Cases of venous thromboembolism (VTE), sometimes fatal, have been reported with antipsychotic drugs. Since patients treated with antipsychotics often present with acquired risk factors for VTE, all possible risk factors for VTE should be identified before and during treatment with Stemzine and preventative measures undertaken. Therefore, prochlorperazine should be used with caution in patients with risk factors for thromboembolism (see Section 4.8 Adverse Effects (Undesirable Effects)).

Hyperglycaemia.

Hyperglycaemia or intolerance to glucose has been reported in patients treated with prochlorperazines. Patients with an established diagnosis of diabetes mellitus or with risk factors for the development of diabetes who are started on prochlorperazine, should get appropriate glycaemic monitoring during treatment (see Section 4.8 Adverse Effects (Undesirable Effects)).

Alcohol use.

Patients are strongly advised not to consume alcohol and alcohol-containing medicines while being treated with Stemzine.

Use in hepatic impairment.

Caution should be used in patients with existing liver disease due to the extensive hepatic metabolism of prochlorperazine. A past history of jaundice resulting from phenothiazine therapy indicates a hypersensitivity reaction and there is a likelihood of cross sensitivity to other phenothiazines.

Use in the elderly.

It should be used with caution in the elderly, particularly during very hot or very cold weather (risk of hyper-, hypothermia).
Stemzine should be used cautiously in the elderly owing to their susceptibility to drugs acting on the central nervous system and a lower initial dosage is recommended. There is an increased risk of drug-induced Parkinsonism in the elderly particularly after prolonged use.
Care should also be taken not to confuse the adverse effects of Stemzine, e.g. orthostatic hypotension, with the effects due to the underlying disorder.
Elderly patients with dementia related psychosis treated with antipsychotic drugs are at an increased risk of death. Although the causes of death in clinical trials with atypical antipsychotics were varied, most of the deaths appeared to be either cardiovascular (e.g. heart failure, sudden death) or infectious (e.g. pneumonia) in nature. Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality. The extent to which the findings of increased mortality in observational studies may be attributed to the antipsychotic drug as opposed to some characteristic(s) of the patients is not clear.
Prolonged administration of any phenothiazine may result in tardive dyskinesias, particularly in the elderly.
Stemzine is not licensed for the treatment of dementia-related behavioural disturbances.
Careful monitoring of treatment with prochlorperazine is required when administered in elderly patients exhibiting greater susceptibility to orthostatic hypotension, sedation, and extrapyramidal effects; chronic constipation (risk of ileus paralytic); possible prostatic hypertrophy.

Paediatric use.

(See Section 4.2 Dose and Method of Administration; Section 4.3 Contraindications.)
Prochlorperazine should not be used in children under 2 years unless potentially life-saving.
Prochlorperazine is not recommended for use in children less than 10 kg, or under 2 years of age as acute extrapyramidal reactions are more likely to occur.
Prolonged administration of any phenothiazine may result in tardive dyskinesias, particularly in children.
The extrapyramidal symptoms which can occur secondary to prochlorperazine may be confused with the CNS signs of an undiagnosed primary disease responsible for the vomiting, e.g. Reye's syndrome or other encephalopathy. The use of prochlorperazine should be avoided in children and adolescents whose signs and symptoms suggest Reye's syndrome.
Children with an acute febrile illness (e.g. chickenpox, CNS infection, measles, gastroenteritis) or suffering from dehydration seem to be much more susceptible than adults to neuromuscular reactions, particularly dystonias. In such patients, the drug should be used under close supervision and at low doses.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Contraindicated combinations.

Dopaminergics, except in patients with Parkinson's disease.
Mutual antagonism between dopaminergics and neuroleptics.
Where treatment for neuroleptic-induced extrapyramidal symptoms is required, anticholinergic antiparkinsonian agents should be used in preference to levodopa, since neuroleptics antagonise the antiparkinsonian action of dopaminergics.
Adrenaline must not be used in patients overdosed with Stemzine (see Section 4.9 Overdose).
Simultaneous administration of desferrioxamine and prochlorperazine has been observed to induce transient metabolic encephalopathy characterised by loss of consciousness for 48-72 hours.

Combinations not recommended or requiring precaution.

Dopaminergics in patients with Parkinson's disease.
Dopaminergics may cause or exacerbate psychotic disorders. If treatment with neuroleptics is required in patients with Parkinson's disease treated with a dopaminergic, the latter should be tapered off gradually (sudden discontinuation of dopaminergic agents exposes the patient to a risk of "neuroleptic malignant syndrome"). For parkinsonian patients who require treatment with both a neuroleptic and a dopaminergic agent, use the minimum effective doses of both medications.
Caution is required with the use of the following medicines due to the risk of QT prolongation (see Section 4.4 Special Warnings and Precautions for Use):
Class Ia antiarrhythmic agents such as quinidine and disopyramide.
Class III antiarrhythmic agents such as amiodarone and sotalol.
Other medications such as bepridil, cisapride, sultopride, thioridazine, methadone, intravenous erythromycin, intravenous vincamine, halofantrine, pentamidine, sparfloxacin.
Medicines which induce bradycardia, such as bradycardia-inducing calcium channel blockers (diltiazem, verapamil), beta-blockers, clonidine, guanfacine, digitalis.
Medicines which can cause hypokalaemia, such as diuretics, stimulant laxatives, intravenous amphotericin B (amphotericin), glucocorticoids, tetracosactide (tetracosactrin).
Other antipsychotics.
Prochlorperazine may enhance the CNS depressant effects of alcohol and other depressant drugs, and potentiate the anticholinergic effects of atropinic agents and tricyclic antidepressants. Respiratory depression may occur. Impaired vigilance may make it dangerous to drive or use machines. Avoid consumption of alcoholic beverages and medications containing alcohol.
Anticholinergic agents may reduce the antipsychotic effect of neuroleptics. The mild anticholinergic effect of prochlorperazine may be enhanced by other anticholinergic drugs, possibly leading to dry mouth, constipation, heat stroke, urinary retention and other adverse effects.
Some drugs interfere with absorption of prochlorperazine:
Anti-Parkinson drugs.
Lithium.
Gastro-intestinal agents that are not absorbed (magnesium, aluminium and calcium salts, oxides and hydroxides): Reduced gastro-intestinal absorption of phenothiazine neuroleptics may occur. Such gastro-intestinal agents should not be taken at the same time as prochlorperazine.
High doses of prochlorperazine reduce the response to hypoglycaemic agents, the dosage of which might have to be raised.
The hypotensive effect of most antihypertensive drugs especially alpha adrenoceptor blocking agents may be exaggerated by prochlorperazine.
The action of some drugs may be opposed by prochlorperazine; these include amfetamine, levodopa, clonidine, guanethidine, adrenaline.
Increases or decreases in the plasma concentrations of a number of drugs, e.g. propranolol, phenobarbital have been observed.
There is an increased risk of agranulocytosis when prochlorperazine is used concurrently with drugs with myelosuppressive potential, such as carbamazepine or certain antibiotics and cytotoxics.
In patients treated concurrently with prochlorperazine and lithium, there have been rare reports of neurotoxicity.

Cytochrome P450 2D6 metabolism.

Some phenothiazines are moderate inhibitors of CYP2D6. There is a possible pharmacokinetic interaction between inhibitors of CYP2D6, such as phenothiazines, and CYP2D6 substrates. Co-administration of prochlorperazine with amitriptyline, a CYP2D6 substrate, may lead to an increase in the plasma levels of amitriptyline. Monitor patients for dose-dependent adverse reactions associated with amitriptyline.
Stemzine should be avoided in patients taking monamine oxidase inhibitors (MAOIs). If Stemzine use is required, MAOIs should be ceased at least 14 days prior to Stemzine commencement..
Because of convulsive risk, the combined use of medicinal products which lower the seizure threshold should be carefully assessed.
Procarbazine has been reported to potentiate the extrapyramidal side effects encountered with the use of prochlorperazine. Phenothiazines have been reported both to impair and increase metabolism of phenytoin, with uncertain clinical significance. Patients on levodopa should not be given phenothiazines because the two drugs are physiologically antagonistic.
Thiazide diuretics may accentuate the orthostatic hypotension that may occur with phenothiazines.
Anithypertensive effects of guanethidine and related compounds may be counteracted when phenothiazines are used concomitantly.
Phenothiazines can diminish the effect of oral anticoagulants. Concomitant administration of propranolol with phenothiazines results in increased plasma levels of both drugs. Phenothiazines may lower the convulsive threshold; dosage adjustments of anticonvulsants may be necessary.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category C)
The use of Stemzine is not recommended during pregnancy and in women of childbearing potential not using contraception, unless the potential benefits outweigh the potential risks.
Data from epidemiological studies cannot exclude the risk of congenital malformations in children exposed in utero to Stemzine.
Neuroleptics may occasionally prolong labour and at such time should be withheld until the cervix is dilated 3-4 cm.
When given in high doses during late pregnancy, phenothiazines have caused jaundice, hyperreflexia, hyporeflexia or prolonged extrapyramidal and neurological disturbances in the child. There is evidence of harmful effects in animals. The following effects have been reported (in postmarketing surveillance) in neonates exposed to phenothiazines during the third trimester of pregnancy:
various degrees of respiratory disorders ranging from tachypnoea to respiratory distress, bradycardia and hypotonia, most often when other drugs such as psychotropic or antimuscarinic drugs were coadministered;
signs related to the atropinic properties of phenothiazines such as meconium ileus, delayed meconium passage, initial feeding difficulties, abdominal bloating, tachycardia;
neurological disorders such as extrapyramidal symptoms including tremor and hypertonia, somnolence, agitation.
Appropriate monitoring and treatment of neonate born to mothers receiving prochlorperazine is recommended.
Like other drugs it should be avoided in pregnancy unless the physician considers it essential. Possible adverse effects on the foetus include lethargy or paradoxical hyperexcitability, tremor and a low Apgar score.
Phenothiazines may be excreted in milk, therefore, breastfeeding is not recommended during treatment with Stemzine.
Trace amounts of another phenothiazine, chlorpromazine, have been detected in breast milk, but there is no information available for prochlorperazine. Consequently, it is not known whether it is excreted in breast milk or whether it has a harmful effect on the newborn.

4.7 Effects on Ability to Drive and Use Machines

Patients should be warned about drowsiness and advised not to drive or operate machinery, particularly during the early days of treatment, until they know how Stemzine affects them.

4.8 Adverse Effects (Undesirable Effects)

The following reactions have been reported for prochlorperazine or phenothiazines in general.

Vascular disorders.

More common: Orthostatic hypotension. Elderly or volume depleted patients are particularly susceptible; it is more likely to occur after intramuscular injection.
Not known: Cases of venous thromboembolism, including cases of pulmonary embolism, sometimes fatal, and cases of deep vein thrombosis have been reported with antipsychotic drugs (see Section 4.4 Special Warnings and Precautions for Use).

Blood and lymphatic system disorders.

Not known: Eosinophilia.
Less common: Agranulocytosis, atypical lymphocytes, thrombocytopenia, leucopenia, aplastic anaemia.

Biochemical abnormalities.

Less common: Elevated serum levels of bilirubin and hepatic enzymes may occur if the patient develops cholestatic jaundice.

Cardiac disorders.

Peripheral oedema, cardiac arrhythmias, ECG changes, QT interval prolongation, ST depression, U-Wave and T-Wave changes. Cardiac arrhythmias, including ventricular arrhythmias and atrial arrhythmias, atrioventricular block, ventricular tachycardia, which may result in ventricular fibrillation or cardiac arrest have been reported during phenothiazine therapy, possibly related to dosage.
Pre-existing cardiac disease, old age, hypokalaemia and concurrent tricyclic antidepressants may predispose patients to cardiac events. There have been reports of sudden death, with possible causes of cardiac origin (see Section 4.4 Special Warnings and Precautions for Use), as well as cases of unexplained sudden death, in patients receiving neuroleptic phenothiazines.
Not known: Torsades de pointes.

Skin and subcutaneous tissue disorders.

Less common: Dermatitis allergic, maculopapular eruptions, erythema multiforme, urticaria, photosensitivity reaction, pigmentation disorder.
Less common: Contact skin sensitisation may occur rarely in those frequently handling preparations of certain phenothiazines (see Section 4.4 Special Warnings and Precautions for Use).

Endocrine disorders.

Less common: Endocrine disturbances including elevated prolactin levels, hyperglycaemia, intolerance to glucose, hypoglycaemia, menstrual irregularities, galactorrhoea, gynaecomastia, amenorrhoea, erectile dysfunction.
Not known: Temperature regulation disorder.

Gastrointestinal.

More common: Constipation, dry mouth.
Less common: Paralytic ileus.

Genitourinary, Renal and urinary disorders.

Less common: Urinary retention.

Hepatobiliary disorders.

Less common: Jaundice cholestatic, liver damage.

Nervous system disorders.

More common: Drowsiness, akathisia, parkinsonism, (with dyskinesia, tremor and rigidity.
Less common: Dystonia or dyskinesias, including oculogyric crisis usually transitory are commoner in children and young adults, and usually occur within the first 4 days of treatment or after dosage increases.
Less common: Tardive dyskinesia: If this occurs it is usually, but not necessarily, after prolonged or high dosage. It can even occur after treatment has been stopped. Dosage should therefore be kept low whenever possible.
Less common: Torticollis and opisthotonus and trismus, seizures, EEG changes, headache, insomnia, catatonia, hyperpyrexia, agitation, dizziness.
Less common: Seizures have been reported.
Not known: Anticholinergic effects such as ileus paralytic, risk of urinary retention, dry mouth, constipation, accommodation disorder.
Not known: Extrapyramidal syndrome:
Akinesia with or without hypertonia, partially relieved by anticholinergic antiparkinsonian agents.
Hyperkinetic-hypertonic movements, motor excitation.
Akathisia.
Not known: Insomnia.
Not known: Convulsions.
Not known: Dizziness.
Not known: Sedation or somnolence.
Not known: Neuroleptic malignant syndrome (hyperthermia, rigidity, autonomic dysfunction and altered consciousness) may occur with any neuroleptic (see Section 4.4. Special Warnings and Precautions for Use).

Eye disorders.

More common: Blurred vision.
Less common: Pigmentary retinopathy.
Less common: Corneal deposits (brownish deposits in the anterior segment of the eye, due to accumulation of the drug and generally without effect on vision).
Not known: Accommodation disorder.
Ocular changes and the development of metallic greyish-mauve coloration of exposed skin have been noted in some individuals mainly females, who have received chlorpromazine continuously for long periods (four to eight years). This could possibly happen with Stemzine.

Psychiatric disorders.

Less common: Activation of psychotic symptoms.
Not known: Agitation, confusional state, delirium, anxiety.

Respiratory, thoracic and mediastinal disorders.

Less common: Respiratory depression, nasal congestion.

Metabolism and nutrition disorders.

Less common: Hyponatraemia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) have also been reported.
In post-marketing surveillance cases of hyperglycaemia or intolerance to glucose have been reported with antipsychotic phenothiazines (see Section 4.4 Special Warnings and Precautions for Use).

Immune system disorders.

Less common: Type 1 hypersensitivity reactions such as angioedema and urticaria have been reported.
Less common: Anaphylactic reaction.

Reproductive system and breast disorders.

Less common: Priapism, ejaculation disorder.

Pregnancy, puerperium and perinatal conditions.

Drug withdrawal syndrome neonatal (see Section 4.6 Fertility, Pregnancy and Lactation, Use in pregnancy).

Investigations.

Not known: Weight increased, liver function test abnormal.

Serious or life threatening reactions.

Prochlorperazine can cause very serious acute dystonic reactions in children leading to cyanosis from laryngospasm, apnoea requiring artificial ventilation, life threatening tetanus like syndromes, coma and even death. These reactions can occur with a single therapeutic dose. For treatment, see Section 4.9 Overdose. Also, long-term phenothiazine therapy has been associated with ECG changes and life threatening cardiac arrhythmias.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems (Australia).

4.9 Overdose

Symptoms.

Overdosage with phenothiazines may cause CNS depression progressing from drowsiness to coma with areflexia. Patients with early or mild intoxication may experience restlessness, confusion and excitement.
Other symptoms include hypotension, tachycardia, hypothermia, pupillary constriction, restlessness, tremor, muscle twitching, spasm or rigidity, convulsions, muscular hypotonia, difficulty in swallowing or breathing, cyanosis and respiratory and/or vasomotor collapse, possibly with sudden apnoea. There is no information available regarding lethal dose in man.
High doses cause depression of the central nervous system, presenting as lethargy, dysartria, ataxia, stupor, reduction in consciousness into coma, convulsions; mydriasis; cardiovascular symptoms (related to risk of QT interval prolongation), such as hypotension, ventricular tachycardia and arrhythmia; respiratory depression; hypothermia. These effects may be potentiated by other medicines or by alcohol. Anticholinergic syndrome may occur.
Extremely serious parkinsonian syndrome may occur.

Treatment.

In the event of overdose of Stemzine, take all appropriate measures immediately.

Acute dystonic reactions.

Intramuscular benztropine (or another antiparkinsonian agent) should be given immediately (adults: 1 to 2 mg i.m., children: 0.2 mg i.m. initially with increments if necessary).

Overdosage.

Emesis should not be induced, not only because the antiemetic action of prochlorperazine prevents the effect of the emetic agent, but also because the sedative and extra-pyramidal side effects increase the risk of pulmonary aspiration should vomiting occur. Management is generally supportive with particular attention to the possibility of obstructed ventilation, severe hypotension, hypothermia, cardiac arrhythmias, convulsions and prolonged deep sedation. Acute dystonic reactions usually occur early (if at all); treatment is with anticholinergic agents, as above.
Adrenaline must not be used as it may cause a paradoxical further lowering of blood pressure.
For information on the management of overdose, contact the Poison Information Centre on 131126 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Prochlorperazine is a phenothiazine with a piperazine moiety in the side chain. It possesses strong antiemetic and antipsychotic activity with less sedative action than chlorpromazine.

Mechanism of action.

As with other phenothiazines, prochlorperazine has actions on several neurotransmitter systems:
1. Antidopamine action, which probably contributes to both the therapeutic effect and unwanted effects including extrapyramidal disorders and endocrine disturbances.
2. α-Adrenoreceptor antagonism, which contributes to cardiovascular side effects such as orthostatic hypotension and reflex tachycardia.
3. Potentiation of noradrenaline by blocking its reuptake into nerve terminals.
4. Weak anticholinergic action.
5. Weak antihistamine action.
6. Weak serotonin antagonism.
Prochlorperazine also has an effect on temperature control and blocks conditioned avoidance responses.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

There are few published data on prochlorperazine pharmacokinetics in the human. Most studies have been done in rats and dose levels do not correspond to those used clinically and metabolic pathways may differ. Similar overall pharmacokinetic patterns however would occur in the human.

Absorption.

Prochlorperazine is well absorbed from the GI tract in rats but absorption is slowed in repeatedly treated animals.

Distribution.

The drug is widely distributed to tissues including the brain, fat, kidney, heart and skin and is stored in reticuloendothelial tissues.

Metabolism.

Phenothiazines are metabolised primarily in the liver and are subject to enterohepatic circulation.

Excretion.

Excretion is mainly in the faeces. Only a very small amount (approx. 0.1%) of prochlorperazine and its metabolites are excreted in the first 24 hours in the urine and the drug may continue to be excreted in the urine for up to 3 weeks after cessation of long term therapy. The elimination half-life is approximately 24 hours, presumably due to its enterohepatic circulation.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Calcium hydrogen phosphate dihydrate, magnesium stearate, sodium lauryl sulfate, wheat starch.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 30°C. Protect from light.

6.5 Nature and Contents of Container

Stemzine tablets are available in blister packs of 25 and 100* tablets.
*Not marketed.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Prochlorperazine maleate contains 62% of the active base. It is an odourless, nonhydroscopic, white or almost white, fine granular powder, which becomes coloured on exposure to light. It is very slightly soluble in water (less than 0.1% at 20°) and in alcohol, practically insoluble in ether.

Chemical structure.

Prochlorperazine is 2-chloro-10-[3-(4-methylpiperazin-1-yl)propyl]phenothiazine. The chemical structure of prochlorperazine maleate is as follows:
Molecular Formula: C20H24ClN3S.2C4H4O4.

CAS number.

84-02-6.

7 Medicine Schedule (Poisons Standard)

Prescription Only Medicine (Schedule 4).

Summary Table of Changes