Consumer medicine information

Clofen

Baclofen

BRAND INFORMATION

Brand name

Clofen

Active ingredient

Baclofen

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Clofen.

SUMMARY CMI

CLOFEN

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 CLOFEN?

CLOFEN contains the active ingredient baclofen. Baclofen belongs to a group of medicines called muscle relaxants.

CLOFEN is used to reduce the stiffness or spasms in your muscles to help make you more mobile and able to manage your daily activities.

For more information, see Section 1. Why am I using CLOFEN? in the full CMI.

2. What should I know before I use CLOFEN?

Do not use if you have ever had an allergic reaction to baclofen 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 CLOFEN? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with CLOFEN 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 CLOFEN?

  • Your doctor will tell you exactly how many tablets of CLOFEN to take.
  • Do not exceed the recommended dose prescribed by your doctor.
  • Treatment is usually started in hospital with small doses of CLOFEN. The dose is then gradually increased to an amount that works best for you

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

5. What should I know while using CLOFEN?

Things you should do
  • Remind any doctor, dentist or pharmacist you visit that you are using CLOFEN.
  • Keep all doctor's appointments, so that your progress can be checked.
Things you should not do
  • Do not stop using this medicine suddenly, unless your doctor tells you to.
Driving or using machines
  • Be careful before you drive or use any machines or tools until you know how CLOFEN affects you.
  • CLOFEN may cause sleepiness in some people, especially when you start taking it.
Drinking alcohol
  • Tell your doctor if you drink alcohol.
Looking after your medicine
  • Store the tablets in a cool dry place.
  • Keep out of reach of children.

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

6. Are there any side effects?

Common side effects include daytime sleepiness, lack of energy, tiredness, dizziness or light-headedness, vertigo, confusion, headache, difficulty sleeping or nightmares, nausea, retching or vomiting, constipation, stomach cramps or diarrhoea, loss of appetite, stuffy nose, dry mouth, change in sense of taste, misuse, abuse and dependence, numbness, muscle weakness or spasms, swelling of ankles, blurred vision, ringing in the ears, frequent urination, excessive sweating, weight gain, impotence or inability to ejaculate, increased blood sugar, low body temperature. 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

CLOFEN

Active ingredient: Baclofen


Consumer Medicine Information (CMI)

This leaflet provides important information about using CLOFEN. 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 CLOFEN.

Where to find information in this leaflet:

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

1. Why am I using CLOFEN?

CLOFEN contains the active ingredient baclofen. Baclofen belongs to a group of medicines called muscle relaxants.

CLOFEN is used to reduce the stiffness or spasms in your muscles to help make you more mobile and able to manage your daily activities. These spasms happen in various illnesses such as multiple sclerosis and diseases or physical injuries of the spinal cord.

Because this medicine reduces spasms and the pain that goes with them, it helps to make you more mobile and better able to manage your daily activities.

2. What should I know before I use CLOFEN?

Warnings

Do not use CLOFEN if:

  • you are allergic to baclofen, or any of the ingredients listed at the end of this leaflet.
  • Always check the ingredients to make sure you can use this medicine.
  • 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 take this medicine after the expiry date printed on the pack or if the packaging is torn or shows signs of tampering.

Check with your doctor if you:

  • have any other medical conditions including mental illness, Parkinson's disease, seizures (fits) from any cause, stiffness and restriction of movement in a group of muscles, stomach ulcers, stroke or blood circulation problems, diabetes, a blood disorder known as porphyria (a rare disturbance in the production of porphyrin, a pigment important for liver function and blood formation), high blood pressure, difficulty urinating
  • have problems with your heart, kidney, liver or lungs
  • have a history of alcoholism, drink large amounts of alcohol, or have a history of drug abuse or dependence
  • have had thoughts of self-harm or and suicidal thoughts
  • take any medicines for any other condition
  • have any questions about why this medicine has been prescribed for you.

Your doctor may want to take special precautions if you have any of the above conditions. These precautions may include additional tests during or prior to taking CLOFEN.

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?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant.

Talk to your doctor if you are breastfeeding or intend to breastfeed.

There is very little information on the use of this medicine in pregnancy or breastfeeding. Your doctor can discuss with you the risks and benefits involved.

If you have to take CLOFEN when you are pregnant, your baby may have convulsions and other symptoms related to sudden discontinuation of the medicine just after delivery.

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 CLOFEN and affect how it works. These include:

  • Any medicine that makes you sleepy such as medicines used to help you sleep or calm you, pain relievers, and medicines for cold or allergies
  • medicines used to treat mood disorders, including tricyclic antidepressants, lithium and monoamine oxidase inhibitors (MAOIs)
  • medicines used to treat diabetes
  • medicines for high blood pressure
  • medicines used to treat Parkinson's disease, including selegiline and levodopa and carbidopa

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

4. How do I use CLOFEN?

How much to take

  • Your doctor will tell you exactly how many tablets of CLOFEN to take.
  • Do not exceed the recommended dose prescribed by your doctor.
  • Treatment is usually started in hospital with small doses of CLOFEN. The dose is then gradually increased to an amount that works best for you. For example, CLOFEN may be started at a dose of 15 mg per day, then increased slowly to anywhere from 30 to 75 mg a day. Sometimes, doses up to 100 mg a day may be needed.
  • If you are under the age of 16 or over 65, or you have kidney disease, your doctor may start you on a lower dose and increase it slowly to prevent unwanted side effects.
  • Follow the instructions provided and use CLOFEN until your doctor tells you to stop.

When to take CLOFEN

  • CLOFEN is usually taken in 3 divided doses throughout the day.
  • Your doctor may tell you to take it more or less often, depending on your situation.

How to take CLOFEN

  • Swallow the tablets whole during meals with a glass of water or other liquid.

If you forget to use CLOFEN

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take it as soon as you remember and then go back to taking it as you would normally.

Do not take a double dose to make up for the dose you missed.

If you use too much CLOFEN

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

You should immediately:

  • phone the Poisons Information Centre (Australia telephone 13 11 26) for advice, 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.

Symptoms of overdose include:

  • Main symptoms such as drowsiness, breathing difficulties, consciousness disorder and being unconscious (coma).
  • Other symptoms such as feeling confused, hallucinations, agitation, convulsions, blurred vision, unusual low muscle tone, sudden and involuntary muscle spasm, poor or absent reflexes, high or low blood pressure, slow, fast or irregular heartbeat, low body temperature, nausea, vomiting, diarrhoea, excessive salivation, trouble breathing during sleep (sleep apnoea), severe pain in your muscles with fever and dark urine (rhabdomyolysis) and ringing in the ears.
  • If you have kidney disease and have accidentally taken more tablets than your doctor has prescribed, you may experience some neurological symptoms of overdose such as drowsiness, feeling confused or hallucinations.

5. What should I know while using CLOFEN?

Things you should do

Keep all doctor's appointments, so that your progress can be checked.

Call your doctor straight away if you:

  • Become pregnant or think you might be pregnant

Remind any doctor, dentist or pharmacist you visit that you are using CLOFEN.

To help prevent unwanted side effects from happening, your doctor may want to do some tests from time to time during the course of your treatment.

If your muscle spasms come back, tell your doctor.

Your doctor may be able to change the dose of CLOFEN to make it work better for you.

Call your doctor straight away or go to a hospital if you have thoughts of harming or killing yourself.

Some people treated with CLOFEN have had thoughts of harming or suicide or have tried to kill themselves. Ask a relative or close friend to tell you if they are worried about any changes in your behaviour and ask them to read this leaflet.

Things you should not do

  • Do not stop using this medicine suddenly unless your doctor tells you to.
  • Do not use this medicine to treat any other problems unless your doctor tells you to.
  • Do not give this medicine to anyone else. Even if they have the same condition as you.

Stopping this medicine suddenly may bring on severe spasms and other unwanted symptoms, such as nervousness, feeling confused, hallucinations, abnormal thinking or behaviour, convulsions, uncontrollable twitching, jerking or writhing movements, fast heartbeat, high body temperature, pain in muscles, fever and dark urine. The excessive stiffness (spasms) in your muscles may also get worse.

If CLOFEN must be stopped, your doctor will reduce the dose gradually over a period of 1 to 2 weeks so that these unwanted effects are avoided.

Driving or using machines

Be careful before you drive or use any machines or do other jobs that require you to be alert until you know how CLOFEN affects you.

CLOFEN may cause sleepiness and decreased alertness in some people, especially when you start taking it.

Drinking alcohol

Tell your doctor if you drink alcohol.

Be careful when drinking alcohol while taking CLOFEN.

Alcohol may make you feel more sleepy when taking CLOFEN.

Looking after your medicine

  • Keep your tablets in the original container until it is time to take them

Follow the instructions on the label on how to take care of your medicine properly.

Store it in a cool dry place away from moisture, heat or sunlight below 25°C; 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.

A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.

When to discard your medicine

If your doctor tells you to stop taking CLOFEN or the expiry date on the medicine has passed, ask your pharmacist what to do with any tablets you have left over.

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.

Do not use this medicine after the expiry date.

6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

Side effects happen mainly at the start of treatment with CLOFEN or if the dose is too high or increased too quickly. They can often be relieved by lowering the dose. Your doctor will adjust your dose if necessary.

If you are over 65 years of age, you should be especially careful while taking this medicine. Report any side effects promptly to your doctor.

As people grow older, they are more likely to get side effects from medicines.

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
Brain and nerves:
  • daytime sleepiness or drowsiness
  • lack of energy, tiredness
  • dizziness or light-headedness
  • spinning sensation (vertigo)
  • mental confusion
  • headache
  • difficulty sleeping or nightmares
  • change in sense of taste
  • blurred or double vision
  • ringing in the ears
Airways:
  • stuffy or blocked nose
  • dry mouth
Stomach problems:
  • nausea (feeling sick), retching or vomiting
  • constipation, stomach cramps or diarrhoea
  • loss of appetite
General problems:
  • numbness or tingling in hands and feet
  • muscle weakness, spasms or pain
  • problems with coordination and balance
  • difficulty in speaking
  • swelling of ankles due to fluid build-up
  • frequent urination or bed wetting
  • excessive sweating
  • weight gain
  • impotence or inability to ejaculate
  • increased blood sugar
  • feeling cold
  • misuse, abuse and dependence
Speak to your doctor if you have any of these less serious side effects and they worry you.

If these side effects become severe, please tell your doctor, pharmacist or healthcare provider.

Serious side effects

Serious side effectsWhat to do
Skin or muscle problems:
  • signs of allergy such as rash, itching or hives on the skin; swelling of the face, lips, tongue or other parts of the body; shortness of breath or wheezing
  • uncontrollable muscle spasms affecting the eyes, head, neck or body
Chest problems:
  • slow or difficult breathing
  • irregular heartbeat (fast or slow)
  • chest pain
Neurological problems:
  • fainting or seizures (fits)
  • depression or other severe mood, behavioural or mental changes
  • hallucinations (hearing or seeing things that are not there)
  • thoughts of suicide
  • Anxiety, confusion, paranoia, and other mental problems following sudden discontinuation of the medicine (drug withdrawal syndrome).
Other problems:
  • being unable to urinate or pain when urinating; blood in the urine
Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

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 CLOFEN contains

Active ingredient
(main ingredient)
baclofen
Other ingredients
(inactive ingredients)
lactose monohydrate
microcrystalline cellulose
calcium hydrogen phosphate
sodium starch glycollate
colloidal anhydrous silica
magnesium stearate
Potential allergensSugars as lactose

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

What CLOFEN looks like

CLOFEN 10 is a flat bevelled edges white tablet with BN over 10 scored tablet (BN/10) on one side and G on the reverse (AUST R 42146).

CLOFEN 25 is a flat bevelled edges white tablet with BN over 25 scored tablet (BN/25) on one side and G on the reverse (AUST R 42147).

Who distributes CLOFEN

Alphapharm Pty Ltd trading as Viatris
Level 1, 30 The Bond
30-34 Hickson Road
Millers Point NSW 2000
www.viatris.com.au
Phone: 1800 274 276

This leaflet was prepared in June 2022.

CLOFEN_cmi\Jun22/00

Published by MIMS July 2022

BRAND INFORMATION

Brand name

Clofen

Active ingredient

Baclofen

Schedule

S4

 

1 Name of Medicine

Baclofen.

2 Qualitative and Quantitative Composition

Each Clofen 10 and Clofen 25 tablet contains baclofen 10 mg and baclofen 25 mg, as the active ingredient, respectively.

Excipients with known effect.

Sugars as lactose.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Clofen 10.

10 mg tablet: white, flat bevelled edged, marked "BN" breakline "10" on one side and "G" on the other.

Clofen 25.

25 mg tablet: white, flat bevelled edged, marked "BN" breakline "25" on one side and "G" on the other.

4 Clinical Particulars

4.1 Therapeutic Indications

Suppression of voluntary muscle spasm in:
multiple sclerosis;
spinal lesions of traumatic, infectious, degenerative, neoplastic and unknown origin, causing: skeletal hypertonus and spastic and dyssynergic bladder dysfunction.
Baclofen is not recommended in Parkinson's disease or spasticity arising from strokes, cerebral palsy or rheumatoid disorders.

4.2 Dose and Method of Administration

Treatment with baclofen should always be started in hospital using small doses which are then gradually increased in a stepwise manner. The lowest dose compatible with an optimal response is recommended. The optimum daily dosage should be individually adapted to each patient's requirements, so that clonus, flexor and extensor spasms, and spasticity are reduced, at the same time retaining enough muscle tone to permit active movements and avoiding adverse effects as far as possible.
In order to prevent excessive weakness and falling, baclofen should be used with caution when spasticity is needed to sustain upright posture and balance in locomotion or whenever spasticity is used to maintain function. It may be important to maintain some degree of muscle tone and allow occasional spasms to help support circulatory function.
Abrupt discontinuation of treatment should be avoided (see Section 4.4 Special Warnings and Precautions for Use).
Clofen should be taken during meals with a little liquid.
In adults, Clofen should be given in at least three divided doses daily.

Dosage regimen.

As a rule, treatment should be started with a dose of 5 mg three times daily, subsequently increased at three day intervals by 5 mg three times daily (i.e. the dosage regimen is 5 mg three times a day for three days, then 10 mg three times a day for three days, etc.) until the optimum response has been attained. In certain patients reacting sensitively to drugs, it may be advisable to begin with a lower daily dose (5 mg or 10 mg), increased by smaller steps at longer intervals (see Section 4.4 Special Warnings and Precautions for Use). The optimum dosage generally ranges from 30 to 75 mg daily, although occasionally in hospitalised patients daily doses up to 100 mg may be necessary.
If no benefit is apparent within 6 to 8 weeks of achieving the maximum dosage, a decision whether or not to continue treatment with baclofen should be made.
Discontinuation of the treatment should always be gradual by successively reducing the dosage over a period of approximately 1 to 2 weeks, except in overdose related emergencies, or where serious adverse effects have occurred (see Section 4.4 Special Warnings and Precautions for Use).

Special populations.

Renal impairment.

In patients with impaired renal function or undergoing chronic haemodialysis, low doses (i.e. approximately 5 mg daily) should be used. These patients should be closely monitored for prompt diagnosis of early signs and/or symptoms of toxicity (e.g. somnolence, lethargy) (see Section 4.4 Special Warnings and Precautions for Use; Section 4.9 Overdose). Signs and symptoms of overdosage have been reported with doses above 5 mg daily in this setting (see Section 4.9 Overdose).
Clofen should only be administered to end stage renal failure patients when benefit outweighs risk.

Hepatic impairment.

No studies have been performed in patients with hepatic impairment under baclofen therapy. Baclofen should be prescribed with caution in patients with hepatic impairment (see Section 4.4 Special Warnings and Precautions for Use).

Elderly patients (aged 65 years or above).

Since unwanted effects are more likely to occur in elderly patients (due to increased risk of renal function impairment and CNS toxicity), a very cautious dosage schedule should be adopted and the patient kept under appropriate surveillance.
Toxicity due to baclofen may be mistaken for uraemic encephalopathy.

Paediatric patients.

Baclofen should be given with extreme caution to children under 16 years of age, as only limited data are available. Clofen tablets are not suitable for use in children with a body weight below 33 kg.

Monitoring advice.

Since in rare instances elevated AST, alkaline phosphatase or glucose levels in the serum have been recorded, appropriate laboratory tests should be performed periodically in patients with liver diseases or diabetes mellitus, in order to ensure that no drug induced changes in these underlying diseases have occurred.
Careful monitoring of respiratory and cardiovascular function is essential especially in patients with cardiopulmonary disease and respiratory muscle weakness.

4.3 Contraindications

Known hypersensitivity to baclofen or any of the components of the formulation.

4.4 Special Warnings and Precautions for Use

Psychiatric and nervous system disorders.

Patients suffering not only from spasticity but also from psychotic disorders, schizophrenia, depressive or manic disorders or confusional states should be treated cautiously with baclofen and kept under careful surveillance, because exacerbations of these conditions may occur.
Suicide and suicide-related events have been reported in patients treated with baclofen. In most cases, the patients had additional risk factors associated with an increased risk of suicide including alcohol use disorder, depression and/or a history of previous suicide attempts. Close supervision of patients with additional risk factors for suicide should accompany drug therapy. Patients (and caregivers of patients) should be alerted about the need to monitor for clinical worsening, suicidal behaviour or thoughts or unusual changes in behaviour and to seek medical advice immediately if these symptoms present.
Cases of misuse, abuse and dependence have been reported with baclofen. Caution should be exercised in patients with a history of substance abuse and the patient should be monitored for symptoms of baclofen misuse, abuse or dependence e.g. dose escalation, drug-seeking behaviour, development of tolerance.

Epilepsy or other potential convulsive conditions.

Caution is needed in patients with epilepsy or other convulsive conditions, cortical or subcortical brain damage or significant EEG abnormalities, since ingestion of baclofen may cause deterioration of seizure control and EEG changes, and may precipitate convulsions. In patients with epilepsy and muscle spasticity, baclofen can be used under appropriate supervision, provided adequate anticonvulsive therapy is continued.
Lowering of the convulsion threshold may occur and seizures have been reported occasionally after cessation of baclofen or with overdosage.

Other concomitant conditions.

Baclofen should be used with caution in patients with:
peptic ulcers or with a history of peptic ulcers;
cerebrovascular diseases or respiratory or hepatic insufficiency;
porphyria;
a history of alcoholism;
diabetes mellitus (baclofen may increase blood glucose concentrations);
hypertension (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).
Since unwanted effects are more likely to occur, a cautious dosage schedule should be adopted in elderly and patients with spasticity. Baclofen is not recommended in Parkinson's disease or spasticity arising from strokes, cerebral palsy or rheumatoid disorders.

Changes in muscle tone.

Baclofen should be used with caution in patients who use spasticity to maintain an upright posture and balance in moving. If an undesirable degree of muscular hypotonia occurs, making it more difficult for patients to walk or fend for themselves, this can usually be relieved by adjusting the dosage (i.e. by reducing the doses given during the day and possibly increasing the evening dose).
During treatment with baclofen, neurogenic disturbances affecting emptying of the bladder may improve, whereas in patients with pre-existing sphincter hypertonia, acute retention of urine may occur. The drug should, therefore, be used with caution in such cases.

Abrupt discontinuation.

Anxiety and confusional states, delirium, hallucinations, psychotic, manic or paranoid states, convulsions (status epilepticus), dyskinesia, tachycardia, hyperthermia and, as a rebound phenomenon, temporary aggravation of spasticity, have been reported upon the abrupt withdrawal of baclofen, especially after long-term medication.
Drug withdrawal reactions including postnatal convulsions in neonates have been reported after intrauterine exposure to oral baclofen (see Section 4.6 Fertility, Pregnancy and Lactation, Use in pregnancy).
Except in overdose-related emergencies or where serious adverse effects have occurred, treatment should, therefore, always be gradually withdrawn by successive dosage reduction over a period of approximately 1 to 2 weeks.
If withdrawal symptoms occur, restarting baclofen therapy and withdrawing over a longer period may help to resolve withdrawal problems.

Posture and balance.

Baclofen should be used with caution when spasticity is needed to sustain upright posture and balance in locomotion (see Section 4.2 Dose and Method of Administration).

Use in hepatic impairment.

Because baclofen is partially metabolised in the liver, patients with impaired hepatic function should be periodically monitored with laboratory tests (see Section 4.2 Dose and Method of Administration, Monitoring advice).

Use in renal impairment.

Since baclofen is largely eliminated by the kidneys, a dosage reduction is advised to avoid drug accumulation. Baclofen should be used with caution in patients with renal insufficiency and should only be administered to end stage renal failure patients only if the expected benefit outweighs the potential risk (see Section 4.2 Dose and Method of Administration, Renal impairment).
Neurological signs and symptoms of overdose including clinical manifestations of toxic encephalopathy (e.g. confusion, somnolence, hallucination) have been observed in patients with renal impairment taking baclofen at doses at and above 5 mg daily. Patients with renal impairment should be closely monitored for prompt diagnosis of early signs and symptoms of toxicity (see Section 4.9 Overdose).
Particular caution is required when combining baclofen to drugs or medicinal products that can significantly impact renal function. Renal function shall be closely monitored and baclofen daily dosage adjusted accordingly to prevent baclofen toxicity.
Besides discontinuing treatment, unscheduled haemodialysis might be considered as a treatment alternative in patients with severe baclofen toxicity. Haemodialysis effectively removes baclofen from the body, alleviates clinical symptoms of overdose and shortens the recovery time in these patients.

Use in the elderly.

See Section 4.2 Dose and Method of Administration.

Paediatric use.

Baclofen should be given with extreme caution to children under 16 years, as only limited data are available.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Levodopa/dopa decarboxylase (DDC) inhibitor (carbidopa).

In patients with Parkinson's disease receiving treatment with baclofen and levodopa (alone or in combination with DDC inhibitor, carbidopa), there have been reports of mental confusion, hallucinations, headaches, nausea and agitation. Worsening of the symptoms of Parkinsonism has also been reported. Hence, caution should be exercised during concomitant administration of baclofen and levodopa/carbidopa.

Drugs causing central nervous system (CNS) depression.

Increased sedation may occur where baclofen is taken concomitantly with other drugs causing CNS depression including other muscle relaxants (such as tizanidine), with synthetic opiates or with alcohol (see Section 4.4 Special Warnings and Precautions for Use). The risk of respiratory depression is also increased.
In addition, hypotension has been reported with concomitant use of morphine and intrathecal baclofen. Careful monitoring of respiratory and cardiovascular functions is essential, especially in patients with cardiopulmonary disease and respiratory muscle weakness.

Antidepressants.

During concurrent treatment with tricyclic antidepressants, the effect of baclofen may be potentiated, resulting in pronounced muscular hypotonia.

Lithium.

Concurrent use of baclofen and lithium resulted in aggravated hyperkinetic symptoms. Thus, caution should be exercised when baclofen is used concomitantly with lithium.

Antihypertensives.

Since concomitant treatment with baclofen and antihypertensive agents is likely to increase the risk of hypotension, the dosage of antihypertensive medication should be adjusted accordingly.

Agents reducing renal function.

Drugs or medical products that can significantly impact renal function may reduce baclofen excretion leading to toxic effects (see Section 4.4 Special Warnings and Precautions for Use, Use in renal impairment).

Others.

The concurrent use of baclofen with monoamine oxidase (MAO) inhibitors may result in increased CNS-depressant and hypotensive effects. Caution is recommended and dosage of one or both agents may require reduction.
Since baclofen may increase blood glucose concentrations, dosage adjustments of insulin and/or oral hypoglycaemic agents may be necessary during and after concurrent therapy.
Studies in rats indicate that the agonistic effects of baclofen on gastric acid secretion are potentiated by diazepam.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

There are no data available on the effect of baclofen on fertility in humans.
(Category B3)

Risk summary.

There are no adequate and well-controlled studies in pregnant women. Animal data showed that baclofen crosses the placental barrier. Therefore, baclofen should not be used during pregnancy unless the expected benefit outweighs the potential risk to the foetus.
Drug withdrawal reactions including postnatal convulsions in neonates following intra-uterine exposure to oral baclofen, have been reported. In one suspected case of postnatal baclofen withdrawal, the convulsions were refractory to various anticonvulsants, but responsive to the administration of baclofen to the affected neonate (see Section 4.4 Special Warnings and Precautions for Use, Abrupt discontinuation).
Studies in lactating women are limited to one (1) patient. In this particular case, available evidence suggests that baclofen is found in quantities so small that adverse effects in the infant would have been unlikely.

4.7 Effects on Ability to Drive and Use Machines

Baclofen may be associated with adverse effects such as dizziness, sedation, somnolence and visual disturbance (see Section 4.8 Adverse Effects (Undesirable Effects)) which may impair the patient's reaction. Patients experiencing these adverse reactions should be advised to refrain from driving or using machines.
The patient's ability to react may be adversely affected by sedation and decreased alertness caused by baclofen. Patients should, therefore, exercise due caution when driving a vehicle or operating machinery.

4.8 Adverse Effects (Undesirable Effects)

Adverse effects mainly occur at the start of treatment (e.g. sedation, somnolence), if the dosage is increased too quickly, if large doses are used, or if the patient is elderly. They are often transitory and can be attenuated or eliminated by reducing the dosage. They may necessitate withdrawal of the medication.
In patients with a history of psychiatric illness, cortical or organic brain disorders, or with cerebrovascular disorders (such as stroke), as well as in elderly patients, adverse reactions may be more serious.
It is often difficult to distinguish whether some of these are drug effects or manifestations of the diseases under treatment. Psychiatric manifestations can occur in acute or chronic toxicity due to baclofen.
Lowering of the convulsion threshold and convulsions may occur, particularly in epileptic patients (see Section 4.4 Special Warnings and Precautions for Use).
Certain patients have shown increased muscle spasticity as a paradoxical reaction to the medication.
Adverse reactions are ranked under heading of frequency, the most frequent first, using the following convention: Very common (≥ 1/10); common (≥ 1/100, < 1/10); uncommon (≥ 1/1,000, < 1/100); rare (≥ 1/10,000, < 1/1000); very rare < 1/10,000), not known (cannot be estimated from the available data).

Cardiac disorders.

Common: cardiac output decreased.
Rare: arrhythmias, palpitations, chest pain.
Not known: bradycardia.

Vascular disorders.

Common: hypotension.
Rare: dyspnoea, ankle oedema.

Gastrointestinal disorders.

Very common: nausea (particularly at the start of treatment).
Common: gastrointestinal disorder, constipation, diarrhoea, retching, vomiting.
Rare: colicky abdominal pain, anorexia.

Hepatobiliary disorders.

Rare: hepatic function abnormal.

Nervous system disorders.

Very common: sedation, somnolence.
Common: respiratory depression, fatigue, confusional state, dizziness, personality changes, vertigo, headache, insomnia, euphoric mood, depression, muscular weakness, ataxia, tremor, hallucination, nightmare, myalgia, nystagmus, dry mouth, tinnitus.
Rare: paresthesia, dysarthria, dysgeusia, syncope, dyskinesia, coma, taste disturbances.
Very rare: hypothermia.
Not known: Cases of misuse, abuse and dependence have been reported with baclofen. Suicide and suicide-related events have been reported in patients treated with baclofen (see Section 4.4 Special Warnings and Precautions for Use, Psychiatric and nervous system disorders).

Eye disorders.

Common: accommodation disorders, visual impairment.

Skin and subcutaneous tissue disorders.

Common: hyperhidrosis, rash, pruritus.
Not known: urticaria.

Renal and urinary disorders.

Common: pollakiuria, dysuria, enuresis.
Rare: urinary retention, nocturia, haematuria.

Reproductive system and breast disorders.

Rare: erectile dysfunction, inability to ejaculate.

General disorders and administration site conditions.

Very rare: hypothermia.
Not known: drug withdrawal syndrome.*

Investigations.

Not known: blood glucose increase.

Miscellaneous.

Rare: nasal congestion, weight gain.
* Drug withdrawal syndrome including postnatal convulsions has also been reported after intra-uterine exposure to oral baclofen.

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.

4.9 Overdose

Signs and symptoms.

Prominent features are signs of central nervous depression: somnolence, depressed level of consciousness, respiratory depression due to absent respiratory movement, coma.
Also liable to occur are: confusion, hallucinations, agitation, abnormal electroencephalogram (burst suppression pattern and triphasic waves), accommodation disorders, impaired pupillary reflex; generalised muscular hypotonia, myoclonus, hyporeflexia or areflexia; convulsions; peripheral vasodilatation, hypotension or hypertension, bradycardia, tachycardia or cardiac arrhythmias; hypothermia; nausea, vomiting, diarrhoea, hypersalivation; increased hepatic enzymes, sleep apnoea, rhabdomyolysis, tinnitus.
A deterioration in the condition may occur if various substances or drugs acting on the central nervous system (e.g. alcohol, diazepam, tricyclic antidepressants) have been taken at the same time.
Adult patients have ingested up to 1,125 mg of baclofen and survived. Ingestion of 1,250 to 2,500 mg by one patient was fatal. Serious poisoning has occurred with doses of 150 and 300 mg in adults.

Treatment.

No specific antidote is known.
Supportive measures and symptomatic treatment should be given for complications, such as hypotension, hypertension, convulsions, gastrointestinal disturbances, and respiratory or cardiovascular depression.
Symptomatic treatment should include the following:
Elimination of the drug from the gastrointestinal tract, e.g. administration of activated charcoal; if necessary, saline laxatives.
Since the drug is excreted chiefly via the kidneys, generous quantities of fluid should be given, possibly together with a diuretic.
Measures in support of cardiovascular functions.
In the case of respiratory muscle weakness, administration of artificial respiration.
In the event of convulsions, diazepam should be administered cautiously intravenously, paying attention to increased muscle relaxation, and possible respiratory insufficiency, if the patient is not already being artificially ventilated.
Haemodialysis (sometimes unscheduled) may be useful in severe poisoning associated with renal failure (see Section 4.4 Special Warnings and Precautions for Use).
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Baclofen is an effective antispastic agent with a spinal site of action. Its mechanism of action and pharmacological properties are different from those of other antispastic agents.
Baclofen also has central sites of action given the adverse event profile and general CNS depressant properties.
Baclofen depresses monosynaptic and polysynaptic reflex transmission, probably by various actions, including stimulation of GABAβ-receptors. This stimulation in turn inhibits the release of excitatory amino acids (glutamate and aspartate) in guinea pig preparations. Neuromuscular transmission is not affected by baclofen.
Baclofen exerts an antinociceptive effect. The clinical significance of this awaits clarification. In neurological diseases associated with spasm of the skeletal muscles, the clinical effects of baclofen take the form of a beneficial action on reflex muscle contractions and of marked relief from painful spasm, automatism and clonus. Baclofen, where indicated, improves the patient's mobility, making for greater independence and facilitating passive and active physiotherapy. Baclofen stimulates gastric acid secretion.

Clinical trials.

See Section 4.4 Special Warnings and Precautions for Use, Use in renal impairment; Section 5.1 Pharmacodynamic Properties.

5.2 Pharmacokinetic Properties

Absorption.

Baclofen is rapidly and completely absorbed from the gastrointestinal tract. Maximum concentrations of unchanged drug are achieved in plasma in 2 to 4 hours after an oral dose. The bioavailability of oral baclofen is 70-80%.
Following oral administration of a single dose of 40 mg baclofen, a peak serum concentration between 500 to 600 nanogram/mL was reached. The serum concentration remains above 200 nanogram/mL for 8 hours. The onset of action is highly variable and may range from hours to weeks.

Distribution.

The distribution volume of baclofen amounts to 0.7 L/kg. In cerebrospinal fluid, the active substance attains concentrations approximately 8.5 times lower than in the plasma.
Baclofen is bound to plasma proteins to the extent of approximately 30%.

Metabolism.

About 15% of the baclofen dose is metabolised in the liver. Deamination yields the main metabolite, β-(chlorophenyl)- γ-hydroxybutyric acid, which is pharmacologically inactive.

Excretion.

Approximately 70% of baclofen is eliminated in the urine in the unchanged form. The plasma elimination half-life of baclofen averages 3 to 4 hours. Within 72 hours, approximately 75% of the dose is excreted via the kidneys, approximately 5% of this quantity being in the form of metabolites. The remainder of the dose, including 5% as metabolites, is excreted in the faeces.

5.3 Preclinical Safety Data

Genotoxicity.

Baclofen did not induce mutations in bacterial or mammalian cells in vitro, lacked DNA damaging activity in the sister chromatid exchange assay, and had no clastogenic activity in the nuclear anomaly test.

Animal data.

In two teratogenic studies in pregnant rats, baclofen has been shown to increase the incidence of omphaloceles (ventral hernias) in foetuses at a dose of 20 mg/kg/day, which is maternotoxic. The relevance of this finding to humans is unknown. At the same dose there was also an increased incidence of incomplete sternebral ossification in the foetuses.
In mice, no teratogenic effects were observed at a dose of 81.5 mg/kg/day given via the diet or up to 40 mg/kg/day given by gavage.
At 40 mg/kg/day by gavage, a delay in foetal growth was associated with maternal anorexia. The lack of maternotoxicity seen in the dietary study suggests that the dose used was inadequate.
In pregnant rabbits, oral doses up to 10 mg/kg/day were manifested as a sedative effect. Skeletal examination of foetuses revealed a marked increase in the absence of ossification of the phalangeal nuclei of fore-limbs and hind-limbs.

Carcinogenicity.

A two year carcinogenicity study in rats found no evidence that baclofen had carcinogenic potential at oral doses up to 100 mg/kg/day. An apparently dose related increase in the incidence of ovarian cysts and of enlarged and/or haemorrhagic adrenals at the highest two doses (50 and 100 mg/kg/day) was observed in female rats. The clinical relevance of these findings is not known.
Ovarian cysts have been found by palpation in about 5% of the multiple sclerosis patients who were treated with oral baclofen for up to one year. In most cases these cysts disappeared spontaneously while patients continued to receive the drug. Ovarian cysts are known to occur spontaneously in a proportion of the normal female population.

6 Pharmaceutical Particulars

6.1 List of Excipients

The tablets also contain the following inactive ingredients: lactose monohydrate, microcrystalline cellulose, calcium hydrogen phosphate, sodium starch glycollate, colloidal anhydrous silica, magnesium stearate.

6.2 Incompatibilities

See Section 4.5 Interactions with Other Medicines and Other Forms of Interactions.

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 25°C. The tablets should be kept out of reach of children.

6.5 Nature and Contents of Container

Container type: HDPE bottles with PP lidded child resistant caps.
Pack sizes: available in bottles of 100's.
Some strengths, pack sizes and/or pack types may not be marketed.

Australian Register of Therapeutic Goods (ARTG).

AUST R 42146 - Clofen 10 baclofen 10 mg tablet bottle.
AUST R 42147 - Clofen 25 baclofen 25 mg tablet bottle.

6.6 Special Precautions for Disposal

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

6.7 Physicochemical Properties

Chemical structure.


Chemical name: (3RS)-4-amino-3- (4-chlorophenyl) butanoic acid.
Molecular formula: C10H12ClNO2.
Molecular weight: 213.7.
Baclofen is a derivative of gamma-aminobutyric acid (GABA). It is slightly soluble in water, very slightly soluble in ethanol (96%), practically insoluble in acetone and in ether. It dissolves in dilute mineral acids and in dilute alkali hydroxides.

CAS number.

1134-47-0.
Baclofen is a white or almost white powder.

7 Medicine Schedule (Poisons Standard)

S4 (Prescription Only Medicine).

Summary Table of Changes