Consumer medicine information

Panadol Night Caplets

Paracetamol; Diphenhydramine hydrochloride

BRAND INFORMATION

Brand name

Panadol Night

Active ingredient

Paracetamol; Diphenhydramine hydrochloride

Schedule

S3

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Panadol Night Caplets.

What is in this leaflet?

This leaflet answers some common questions about PANADOL Night. It does not contain all the available information.

It does not take the place of talking to your pharmacist or doctor.

All medicines have risks and benefits. Your pharmacist or doctor has weighed the risks of you taking PANADOL Night against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, ask your pharmacist or doctor.

Keep this leaflet with the medicine. You may need to read it again.

What PANADOL Night is used for

PANADOL Night is used to give temporary relief of pain when associated with sleeping difficulty.

It is useful for headache, migraine, backache, arthritis, rheumatic and muscle pain, neuralgia, toothache or period pain.

Paracetamol is an analgesic. It works to stop the pain messages from getting through to the brain. It also acts in the brain to reduce fever.

Diphenhydramine hydrochloride is an antihistamine that helps you sleep.

Ask your pharmacist or doctor if you have any questions about this medicine. Your pharmacist or doctor may have given you this for another reason.

This medicine is only available from your pharmacist.

Before you take PANADOL Night

Do not take more than the recommended dose as it may cause serious harm to your liver.

When you must not take it

Do not take PANADOL Night if you have an allergy to:

  • any medicine containing paracetamol or diphenhydramine hydrochloride
  • any of the ingredients listed at the end of this leaflet.

Some of the symptoms of an allergic reaction may include:

  • shortness of breath
  • wheezing or difficulty breathing
  • swelling of the face, lips, tongue or other parts of the body
  • rash, itching or hives on the skin

Do not use this medicine if you are taking any other prescription or non-prescription medicines containing paracetamol to treat pain, fever, symptoms of cold and flu, or to aid sleep.

Always read and follow the label.

Do not take PANADOL Night if you have or have had any of the following medical conditions:

  • glaucoma (high pressure in the eyes)
  • stomach or duodenal ulcer or other stomach problems
  • prostate problems
  • bladder problems

Do not take PANADOL Night if you are taking monoamine oxidase inhibitors (MAOIs), a type of medicine used to treat depression.

Do not take PANADOL Night if you have taken other medicine containing paracetamol in the last 4 hours.

Do not take PANADOL Night if you are breastfeeding or plan to breastfeed. It passes into the breast milk and there is a possibility that the baby may be affected.

Do not give PANADOL Night to newborn or premature babies.

Do not give PANADOL Night to children under 12 years of age.

Do not take this medicine after the expiry date (EXP) printed on the pack. If you take it after the expiry has passed, it may not work as well.

Do not take PANADOL Night if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking this medicine, talk to your pharmacist or doctor.

Before you start to take it

Tell your pharmacist or doctor if you have or have had any of the following medical conditions:

  • Liver or kidney disease
  • Underweight or malnourished
  • Regularly drink alcohol
    You may need to avoid using this product altogether or limit the amount of paracetamol that you take.
  • You have a severe infection, are severely malnourished or are a chronic heavy alcohol user as this may increase the risk of metabolic acidosis
Signs of metabolic acidosis include:
- deep, rapid, difficult breathing
- feeling sick (nausea), being sick (vomiting)
- loss of appetite
Contact a doctor immediately if you get a combination of these symptoms
- Epilepsy
- Myasthenia gravis (a muscle dysfunction)
- Prostate gland enlargement or difficulty urinating
- Glaucoma
- Asthma
- Bronchitis or chronic lung disease

Tell your pharmacist or doctor if you take sedatives.

Tell your pharmacist or doctor if you are pregnant or plan to become pregnant. Your pharmacist or doctor will discuss the benefits and possible risks of taking the medicine during pregnancy.

Consider taking the lowest effective dose for the shortest period of time.

If you have not told your pharmacist or doctor about any of the above, tell him/her before you start taking PANADOL Night.

Please see your doctor if your symptoms do not improve.

Keep out of sight and reach of children.

Taking other medicines

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

Some medicines and PANADOL Night may interfere with each other. These include:

  • Warfarin, a medicine used to prevent blood clots
  • Metoclopramide, a medicine used to control nausea and vomiting
  • Medicines used to treat epilepsy or fits
  • Chloramphenicol, an antibiotic used to treat ear and eye infections
  • Alcohol
  • Medicines used to treat depression, especially monoamine oxidase inhibitors and tricyclic antidepressants
  • Medicines used to help you sleep or relax (sedatives and hypnotics)
  • Opioid analgesics, medicines used to treat pain
  • Other antihistamine medicines including cough and cold medicines and those you use on your skin
  • Medicines which make you drowsy or give you a dry mouth (sometimes called anticholinergics). Taking such medicines while you are taking this medicine may increase the chances of side effects
  • Probenecid, a medicine used to treat gout or sometimes given with an antibiotic
  • Cholestyramine, a medicine used to treat high cholesterol levels in the blood

These medicines may be affected by PANADOL Night or may affect how well it works. You may need different amounts of your medicines, or you may need to take different medicines.

Your pharmacist or doctor will have more information on these and other medicines to be careful with or avoid while taking this medicine.

This product contains paracetamol. If you are taking any other medicine containing paracetamol, you must make sure you do not take more than 4000mg paracetamol (including this product) in any 24 hour period. If in doubt, consult your doctor or pharmacist.

How to take PANADOL Night

Do not exceed the stated dose.

Use the smallest dose that you need to treat your symptoms and use the medicine for the shortest period of time necessary.

Follow all directions given to you by your pharmacist or doctor carefully. They may differ from the information contained in this leaflet.

If you do not understand the instructions on the box, ask your pharmacist or doctor for help.

How much to take

Take two caplets.

Do not take more than the stated dose.

If you are over 65 years of age, talk to your pharmacist or doctor about how much to use. Elderly patients are more likely to have side effects from taking this medicine. Carers should be aware that this medicine should not be given to elderly patients with confusion.

How to take it

Take with water or other fluid.

When to take it

Take the caplets at bedtime.

How long to take it

Adults should not take this medicine for more than a few days at a time unless your doctor tells you to take it for longer.

Children aged 12 to 17 years should not take this medicine for more than 48 hours unless on the advice of a doctor.

Children under 12 years of age should not be given PANADOL Night unless a doctor has told you to.

If you forget to take it at bedtime

If you forget to take PANADOL Night at bedtime, you may take it through the night. Do not take a second dose.

If you are not sure what to do, ask your pharmacist or doctor.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or the Poisons Information Centre (telephone 13 11 26) for advice or go to Accident and Emergency at your nearest hospital if you think that you or anyone else may have taken too much PANADOL Night. Do this even if there are no signs of discomfort or poisoning because of the risk of liver failure. You may need urgent medical attention. Keep telephone numbers of these places handy.

While you are using PANADOL Night

Things you must do

Talk to your pharmacist or doctor if your symptoms do not improve. Your pharmacist or doctor will assess your condition and decide if you should continue to take the medicine.

Use PANADOL Night exactly as your pharmacist or doctor has told you to.

Tell all your doctors, dentists and pharmacists that you are using PANADOL Night.

Things you must not do

Children 12 to 17 years:

Do not give paracetamol for more than 48 hours unless a doctor has told you to.

Adults:

Do not take for more than a few days at a time unless your doctor tells you to.

Do not use this medicine to treat any other complaint unless your pharmacist or doctor tells you to.

Do not give this medicine to anyone else even if they have the same condition as you.

Do not take more than the stated dose unless your doctor tells you to.

Do not drink alcohol while taking PANADOL Night.

The sedation effects of alcohol may be increased.

Things to be careful of

This product may cause dizziness, drowsiness, difficulty concentrating or blurred vision. Be careful driving or operating machinery until you know how the medicine affects you.

Please see your doctor if your symptoms do not improve.

Keep out of sight and reach of children.

This medicine may cause sleepiness in some people. If this happens, do not drive or operate machinery.

Side effects

Tell your pharmacist or doctor as soon as possible if you do not feel well while you are taking PANADOL Night.

This medicine helps most people with pain when associated with sleeping difficulty, but it may have unwanted side effects in a few people. All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical attention if you get some of the side effects.

Do not be alarmed by the following lists of side effects. You may not experience any of them.

Tell your pharmacist or doctor to answer any questions you may have.

Tell your pharmacist or doctor if you notice any of the following and they worry you:

  • nausea or dyspepsia
  • drowsiness or sleepiness
  • dry mouth, nose and throat
  • constipation
  • nervousness and irritability
  • anxiety
  • hallucinations
  • twitching or jerking muscles
  • fast heart beat
  • tiredness
  • dizziness
  • difficulty concentrating
  • unsteadiness

The above list includes the more common side effects of your medicine. They are usually mild.

Tell your doctor as soon as possible if you notice any of the following:

  • difficult or painful urination
  • seizures (fits)

The above list includes serious side effects that may require medical attention. These side effects are rare.

If any of the following happen, tell your doctor immediately or go to Accident and Emergency at your nearest hospital:

  • shortness of breath
  • wheezing or difficulty breathing
  • swelling of the face, lips, tongue, throat or other parts of the body
  • rash, peeling, itching or hives on the skin or mouth ulcers
  • previous breathing problems with aspirin or non-steroidal anti-inflammatories, and you experience a similar reaction with this product.
  • unexplained bruising or bleeding

The above list includes very serious side effects. You may need urgent medical attention or hospitalisation. These side effects are very rare.

Tell your pharmacist or doctor if you notice anything that is making you feel unwell.

Other side effects not listed above may also occur in some people.

After taking PANADOL Night

Storage

Keep your medicine in the original pack until it is time to take it. If you keep the caplets out of their packaging, they will not keep well.

Keep your medicine in a cool, dry place where the temperature stays below 30°C. Protect from moisture.

Do not store PANADOL Night or any other medicine in the bathroom or near a sink. Do not leave it on a window sill or in the car. Heat and dampness can destroy some medicines.

Keep it where children and pets cannot reach it. A locked cupboard at least one and a half metres above the ground is a good place to store medicines.

Disposal

Ask your pharmacist what to do with any medicine that is left over, or if the expiry date has passed.

Product description

What it looks like

PANADOL Night is a blue, film coated caplet.

It is marked "Panadol" on the front face and "Night" on the back.

PANADOL Night is supplied in packs of 20 caplets.

Ingredients

Each PANADOL Night caplet contains 500 mg paracetamol and 25 mg diphenhydramine hydrochloride as active ingredients.

It also contains:

  • Starch-maize
  • Starch-pregelatinized maize
  • Povidone
  • Potassium sorbate
  • Magnesium stearate
  • Talc-purified
  • Cellulose-microcrystalline
  • Water-purified
  • Carnauba wax
  • Opadry II complete film coating system 85G60844 Blue
  • PANADOL Night contains no sugar, lactose, alcohol or wheat starch.

Marketed by:

GlaxoSmithKline Consumer Healthcare
82 Hughes Avenue,
Ermington NSW 2115, Australia

AUST R 167596 (PANADOL NIGHT)

This leaflet was prepared in May 2018.

Trademarks are owned by or licensed to the GSK group of companies.

© 2018 GSK group of companies or its licensor.

Helpful advice on managing night pain

Managing pain at night can often be complicated by affecting your ability to get to sleep. When your sleep pattern is affected, pain at night can seem stronger than normal. For this reason we have included some helpful advice on managing pain and getting to sleep.

Pain Management

  1. Application of gentle heat to the painful area. This increases the blood flow to the affected area which works to relieve the sensation of pain and aids the healing process. Hot water bottles, hot showers and heat bags can be useful.
  2. Pain as a result of inflammation can also be treated by the application of cold to the affected area. Cold packs can often be more effective in the early stages of an injury than heat. See your doctor or pharmacist for advice on the best way to treat your pain.
  3. For some people, massage can also help to increase blood flow to an area and contribute to increasing flexibility of joints and muscles. Massage oils may help.

Sleep Routines

  1. Avoid alcohol, caffeine products and nicotine before bedtime.
  2. Avoid large meals before bedtime.
  3. Develop a regular bed time routine. This helps signal to your mind that it is time to go to sleep.
  4. Practice relaxation techniques. There are many useful books and courses available to instruct you on simple, effective techniques.
  5. Ensure your bed is comfortable. Sometimes changing a mattress or pillows can increase your comfort and ability to get to sleep, particularly if you suffer from muscle or joint pain.

NOTE

Suffering from night time pain can be a lonely experience if it also stops you sleeping. Just remember, many people suffer from night time pain, you are not alone. Try some of the above techniques which could help you manage your night time pain.

Published by MIMS June 2020

BRAND INFORMATION

Brand name

Panadol Night

Active ingredient

Paracetamol; Diphenhydramine hydrochloride

Schedule

S3

 

1 Name of Medicine

Paracetamol, diphenhydramine hydrochloride.

2 Qualitative and Quantitative Composition

Active ingredient: Paracetamol 500 mg, diphenhydramine hydrochloride 25 mg.
Contains: potassium sorbate as preservative.
Excipients: For full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Panadol Night is a film coated, blue caplet (capsule shaped tablet) with "PANADOL" printed on one face and "NIGHT" on the other.

4 Clinical Particulars

4.1 Therapeutic Indications

For the temporary relief of pain when associated with sleeping difficulty, for example: headache, migraine, backache, arthritis, rheumatic and muscle pain, neuralgia, toothache or period pain. Relief of fever.

4.2 Dose and Method of Administration

Adults and children over 12 years.

Take 1-2 tablets with water or other fluid only at bedtime. Maximum of two tablets in 24 hours. Do not exceed the stated dose.
Do not use in children under 12 years of age.
Other products containing paracetamol may be taken during the day but the total daily dose of paracetamol must not exceed 4,000 mg in any 24 hour period. Allow at least four hours between taking any paracetamol containing product and Panadol Night.
For adults, paracetamol should not be taken for more than a few days at a time except on medical advice.
For children, paracetamol should not be taken for more than 48 hours except on medical advice.
Do not exceed the stated dose.
To be taken at bedtime.
Should not be used with other anti-histamine containing preparations, including those used on the skin (see Section 4.4 Special Warnings and Precautions for Use).
The lowest dose necessary to achieve efficacy should be used for the shortest duration of treatment.
Keep out of sight and reach of children.

4.3 Contraindications

Not for use in children 12 years of age and younger.
Hypersensitivity to paracetamol, diphenhydramine hydrochloride or to any of the excipients.
Diphenhydramine is contraindicated for use in patients with:
Narrow angle glaucoma;
Stenosing peptic ulcer;
Symptomatic prostatic hypertrophy;
Bladder neck obstruction;
Pyloroduodenal obstruction.
Diphenhydramine is contraindicated for use in:
Newborns or premature infants;
Lactating women;
Patients taking monoamine oxidase inhibitors (MAOIs).
See Section 4.5 Interactions with Other Medicines and Other Forms of Interactions for additional information.

4.4 Special Warnings and Precautions for Use

Identified precautions.

Contains paracetamol. Do not use with any other paracetamol containing products. The concomitant use with other products containing paracetamol may lead to an overdose.
Paracetamol overdose may cause liver failure which can lead to liver transplant or death.
Paracetamol and diphenhydramine hydrochloride should be used with care in patients with:
Impaired hepatic function;
Impaired renal function.
Underlying liver disease increases the risk of paracetamol related liver damage. Patients who have been diagnosed with liver or kidney impairment must seek medical advice before taking this medication.
Avoid use with other antihistamine-containing preparations, including topical antihistamines and other cough and cold medicines.
Avoid concurrent use with alcohol, as diphenhydramine may increase the sedative effects of alcohol. Therefore alcohol should be avoided (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).
Avoid use in elderly patient with confusion. Use with caution in the elderly, who are more likely to experience adverse effects.
Medical advice should be sought before taking in patients with:
Hepatic or renal impairment. Underlying liver disease increases the risk of paracetamol-related liver damage.
Glutathione depleted states as the sue of paracetamol may increase the metabolic acidosis.
Concurrent use of drugs which cause sedation such as tranquilizers, hypnotics and anxiolytics as diphenhydramine may cause an increase in sedative effects (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).
Caution should be exercised in patients with epilepsy or seizure disorders, myasthenia gravis, prostatic hypertrophy, urinary retention, asthma, bronchitis and chronic obstructive pulmonary disease (COPD).
Diphenhydramine hydrochloride may cause drowsiness and may increase the effects of alcohol. Drowsiness may continue the following day. Those affected should not drive or operate machinery; alcohol should be avoided.
Do not take for more than 3 days without consulting a doctor. If symptoms persist, medical advice must be sought.
Use with caution with:
Patients with epilepsy or seizure disorders, myasthenia gravis, narrow-angle glaucoma, prostatic hypertrophy, urinary retention, asthma, bronchitis and chronic obstructive pulmonary disease (CPOD), moderate to severe hepatic impairment and moderate to severe renal impairment.
Monoamine oxidase inhibitors (MAOIs) or within 2 weeks of stopping an MAOI.
Drugs with antimuscarinic properties, e.g. atropine, tricyclic antidepressants.
See Section 4.5 Interactions with Other Medicines and Other Forms of Interactions for additional information.
Cases of hepatic dysfunction/ failure have been reported in patients with depleted glutathione levels, such as those who are severely malnourished, anorexic, have a low body mass index or are chronic heavy users of alcohol.
In patients with glutathione depleted states such as sepsis, the use of paracetamol may increase the risk of metabolic acidosis.
If symptoms persist, medical advice must be sought.
Keep out of sight and reach of children.

Use in hepatic impairment.

Paracetamol and diphenhydramine hydrochloride should be used with care in patients with:
Impaired hepatic function.

Use in renal impairment.

Paracetamol and diphenhydramine hydrochloride should be used with care in patients with:
Impaired renal function.

Use in the elderly.

The elderly may experience paradoxical excitation with diphenhydramine. The elderly are more likely to have central nervous system (CNS) depressive side effects, including confusion. (See Section 4.3 Contraindications.) Should not be taken by elderly patients with confusion and paradoxical excitation in the elderly (see Section 4.4 Special Warnings and Precautions for Use).

Paediatric use.

Children may experience paradoxical excitation with diphenhydramine.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

The following interactions with paracetamol have been noted.
The anticoagulant effect of warfarin and other coumarins may be enhanced by prolonged regular daily use of paracetamol with increased risk of bleeding. Anticoagulant dosage may require reduction if paracetamol and anticoagulants are taken for a prolonged period of time.
Diphenhydramine may potentiate the sedative effects of alcohol and other CNS depressants (e.g. codeine, tranquilizers, hypnotics and anxiolytics) and other antihistamines (see Section 4.4 Special Warnings and Precautions for Use).
Paracetamol absorption is increased by substances that increase gastric emptying, e.g. metoclopramide.
Paracetamol absorption is decreased by substances that decrease gastric emptying, e.g. propantheline, antidepressants with anticholinergic properties and narcotic analgesics.
Paracetamol may increase chloramphenicol concentrations.
The risk of paracetamol toxicity may be increased in patients receiving other potentially hepatotoxic drugs or drugs that induce liver microsomal enzymes such as alcohol and anticonvulsant agents.
Paracetamol excretion may be affected and plasma concentrations altered when given with probenecid.
Colestyramine reduces the absorption of paracetamol if given within 1 hour of paracetamol.
As diphenhydramine has some anticholinergic activity, the effects of some anticholinergic drugs may be potentiated. This may result in tachycardia, dry mouth, blurred vision, gastrointestinal disturbances, urinary retention and headaches (see Section 4.4 Special Warnings and Precautions for Use).
The following interactions with diphenhydramine hydrochloride have been noted.
Central nervous system (CNS) depressants (alcohol, sedatives, opioid analgesics, hypnotics): may cause an increase in sedation effects.
Monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs): may prolong and intensify the anticholinergic and CNS depressive effects.
Diphenhydramine is an inhibitor of the cytochrome P450 isoenzyme CYP2D6. Therefore, there may be a potential for interaction with drugs that are primarily metabolised by CYP2D6, such as metoprolol and venlafaxine.
Avoid use with other antihistamine-containing preparations including topical preparations and cough and cold medicines.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category A)
Both paracetamol and diphenhydramine have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the foetus having been observed.
This product should not be used during pregnancy without medical advice.
Use of sedating antihistamines during the third trimester may result in reactions in the newborn or premature neonates.
Panadol Night should not be used whilst breastfeeding without medical advice.
Paracetamol is excreted in small amounts (< 0.2%) in breast milk. Maternal ingestion of paracetamol in usual analgesic doses does not appear to present a risk to the breastfed infant.
Diphenhydramine is excreted in breast milk. Therefore it is not recommended for breastfeeding mothers unless the potential benefits to the patient are weighed against the possible risk to the infant.

4.7 Effects on Ability to Drive and Use Machines

Panadol Night may cause drowsiness, dizziness, blurred vision, cognitive and psychomotor impairment which can seriously affect the patient's ability to drive or operate machinery. If affected, do not drive or operate machinery.

4.8 Adverse Effects (Undesirable Effects)

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.

Paracetamol.

Side effects of paracetamol are rare and usually mild, although haematological reactions have been reported. Skin rashes and hypersensitivity reactions occur occasionally. Overdosage with paracetamol, if left untreated, can result in severe, sometimes fatal liver damage and rarely, acute renal tubular necrosis.
Adverse events from historical clinical trial data are both infrequent and from small patient exposure. Accordingly, events reported from extensive postmarketing experience at therapeutic/ labelled dose and considered attributable are tabulated in Table 1 by system organ class and frequency.
As the adverse reactions identified from postmarketing use are reported voluntarily from a population of uncertain size, the frequency is not known but likely to be very rare.

Diphenhydramine.

Central nervous system (CNS) effects.

CNS depressive effects of diphenhydramine hydrochloride include sedation and impaired performance (impaired driving performance, poor work performance, incoordination, reduced motor skills and impaired information processing). Performance may be impaired in the absence of sedation and may persist the morning after a night time dose.
CNS stimulatory effects of diphenhydramine may include anxiety, hallucinations, appetite stimulation, muscle dyskinesias and activation of epileptogenic foci.
High doses of diphenhydramine may cause nervousness, tremor, insomnia, agitation and irritability.

Anticholinergic effects.

Side effects of diphenhydramine associated with cholinergic blockage include dryness of the eyes, mouth and nose, blurred vision, urinary hesitancy and retention, constipation and tachycardia.
Adverse reactions that have been observed in clinical trials and which are considered to be common or very common are listed in Table 2. The frequency of other adverse reactions identified during postmarketing use is not known but these reactions are likely to be uncommon or rare.

4.9 Overdose

For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).
If an overdose is taken or suspected, immediately contact the Poisons Information Centre (in Australia, call 131 126; in New Zealand call 0800 764 766) for advice, or go to a hospital straight away even if you feel well because of the risk of delayed, serious liver damage.
Paracetamol overdose may cause liver failure which can lead to liver transplant or death. Acute pancreatitis has been observed, usually with hepatic dysfunction and liver toxicity.
Diphenhydramine overdose is likely to result in effects similar to those listed under adverse reactions. Additional symptoms may include mydriasis, fever, flushing, agitation, tremor, dystonic reactions, hallucinations and ECG changes. Large overdose may cause rhabdomyolysis, convulsions, delirium, toxic psychosis, arrhythmias, coma and cardiovascular collapse.

Treatment.

Paracetamol.

Immediate medical management is required in the event of overdose, even if symptoms of overdose are not present. Administration of N-acetylcysteine or methionine may be required.

Diphenhydramine.

Treatment should be supportive and directed towards specific symptoms. Convulsions and marked CNS stimulation should be treated with parenteral diazepam.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Paracetamol.

Paracetamol is a p-aminophenol derivative that exhibits analgesic and antipyretic activity. It does not possess anti-inflammatory activity. Paracetamol is thought to produce analgesia through a central inhibition of prostaglandin synthesis.
The lack of peripheral prostaglandin inhibition confers important pharmacological properties such as the maintenance of the protective prostaglandins within the gastrointestinal tract. Paracetamol is, therefore, particularly suitable for patients with a history of disease or on concomitant medication, where peripheral prostaglandin inhibition would be undesirable (such as, for example, those with a history of gastrointestinal bleeding or the elderly).

Diphenhydramine hydrochloride.

Diphenhydramine hydrochloride competes with histamine at central and peripheral histamine1 receptor sites, preventing the histamine receptor interaction and subsequent mediator release.
Diphenhydramine is a highly lipophilic molecule that readily crosses the blood brain barrier.
Diphenhydramine is highly selective for histamine1 receptors but has little effect on histamine2 or histamine3 receptors. Diphenhydramine also activates 5-hydroxytryptamine (serotonin) and α-adrenergic receptors and blocks cholinergic receptors.
Diphenhydramine is effective in reducing sleep onset (i.e. time to fall asleep) and increasing the depth and quality of sleep.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Absorption.

Paracetamol.

Paracetamol is readily absorbed from the gastrointestinal tract with peak plasma concentrations occurring about 10 to 60 minutes after oral administration.

Diphenhydramine hydrochloride.

Diphenhydramine hydrochloride is well absorbed from the gastro-intestinal tract, although high first-pass metabolism appears to affect systemic availability. Peak plasma concentrations are achieved about 1 to 4 hours after oral administration. The sedative effect also appears to be maximal within 1-3 hours after administration of a single dose. It is positively correlated with the plasma drug concentration.

Distribution.

Paracetamol.

Paracetamol is distributed into most body tissues. Plasma protein binding is negligible at usual therapeutic doses but increases with increasing doses.

Diphenhydramine hydrochloride.

Diphenhydramine is widely distributed throughout the body, including the CNS. It crosses the placenta and has been detected in breast milk. Diphenhydramine is highly (approx 80-85%) bound to plasma proteins.

Metabolism.

Paracetamol.

Paracetamol is metabolised extensively in the liver and excreted in the urine mainly as inactive glucuronide and sulfate conjugates. Less than 5% is excreted unchanged. The metabolites of paracetamol include a minor hydroxylated intermediate which has hepatotoxic activity. This intermediate metabolite is detoxified by conjugation with glutathione, however, it can accumulate following paracetamol overdosage (more than 150 mg/kg or 10 g total paracetamol ingested) and if left untreated can cause irreversible liver damage.
Paracetamol is metabolised differently by premature infants, newborns, infants and young children compared to adults, the sulfate conjugate being predominant.

Diphenhydramine hydrochloride.

Metabolism is extensive, mainly in the liver. Multiple cytochrome P450 enzymes contribute to the metabolism of diphenhydramine, including CYP2D6. The drug is metabolised principally to diphenylmethoxyacetic acid and is also dealkylated. It undergoes first-pass metabolism in the liver and only about 40-60% of an oral dose reaches systematic circulation as unchanged diphenhydramine. The metabolites are conjugated with glycine and glutamine and excreted in urine.

Excretion.

Paracetamol.

The elimination half-life varies from about 1 to 3 hours.

Diphenhydramine hydrochloride.

Diphenhydramine is excreted mainly in the urine as metabolites; little (about 1%) is excreted as unchanged substance. The elimination half-life has been reported to range from 2.4 to 9.3 hours in healthy adults. The terminal elimination half-life is prolonged in liver cirrhosis.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Starch-maize, starch-pregelatinised maize, povidone, potassium sorbate, magnesium stearate, talc-purified, cellulose-microcrystalline, water-purified, carnauba wax and Opadry II 85G60844 Blue.

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 moisture. Keep out of reach of children.

6.5 Nature and Contents of Container

Panadol Night is available in packs of 20 containing two blisters of 10 caplets each.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of in accordance with local requirements.

6.7 Physicochemical Properties

Chemical structure.


CAS number.

Paracetamol: 103-90-2.
Diphenhydramine hydrochloride: 147-24-0.

7 Medicine Schedule (Poisons Standard)

S3.

Summary Table of Changes