Baclohexal

Generic Name: Baclofen
Product Name: Baclohexal

Indication

Baclohexal (baclofen) belongs to a class of drugs called muscle relaxants and is used to suppress muscle spasms or excess tension associated with disorders such as multiple sclerosis and diseases and injuries of the spinal cord. Multiple sclerosis is a disease associated with loss of conducting layers (myelin) of nerves in the brain and spinal cord which causes a number of neurological problems. Spinal cord disease on the other hand can result from trauma, infections, degeneration or tumours which interfere with muscle and bladder function. In these conditions Baclohexal relieves muscle tension and pain and can help increase your mobility and ability to perform daily activities.

Baclohexal is NOT suitable for all disorders associated with spasticity and is not recommended in disorders such as Parkinson’s disease. You should discuss with your doctor whether Baclohexal is suited for you and your current condition.

Action

Baclohexal is an antispastic agent that acts on the spinal cord as well as centrally to cause CNS depression. Baclohexal works by binding certain receptors called GABA_B receptors in the body. This inhibits the release of excitatory agents that are involved in muscle contraction and spasm. Hence, Baclohexal reduces painful spasm in the aforementioned conditions.

Dose advice

Pregnancy:

If you are pregnant or intend on becoming pregnant- Baclohexal is not recommended during pregnancy as animal studies have shown adverse effects on the fetus and there is limited experience in this group.

Precautions:

1. If you have any other medical conditions- In particular tell your doctor if you have any psychiatric illness, epilepsy, peptic ulceration, cerebrovascular disease, hypertension, lung, liver or renal problems, porphyrias, alcoholism or diabetes mellitus as these can increase your risk of seide effects.
2. If you are allergic to any medications, foods or dyes- Baclohexal is contraindicated in patients with an allergy to Baclofen or any of the inactive ingredients of the tablets.
3. Any other medications you are taking (including those bought from supermarkets or the chemist)- Baclohexal can react with some medicines used to treat depression and lower blood pressure.

Baclohexal comes in a tablet form containing either 10mg or 25mg of the active ingredient baclofen. Tablets are designed to be taken with meals with a glass of water. Treatment with Baclohexal should always be commenced in hospital. You will be started on small doses which will be increased in small increments every three or so days. Your doctor will try to get the ideal dose that relieves your spasticity but still maintains enough tone in your muscles so you can do voluntary movements (such as lifting) and avoids adverse effects. The usual dosage range is 30-75mg daily. If you are younger than 16, older than 65 or have kidney disease you may require a smaller dose with less frequent dose increases to avoid side effects.

You should always take Baclohexal as prescribed by your doctor and should not cease the drug suddenly as it can induce withdrawal symptoms (including anxiety, altered mental status, seizures (including status epilepticus), high fever and rebound spasticity). Your doctor will discuss an appropriate duration of treatment and monitor your progress throughout. Whilst taking Baclohexal it is important to avoid alcohol as this can increase side effects. In addition, you should be careful driving and operating machinery as Baclohexal can cause drowsiness, dizziness and blurred vision. You should avoid these activities until you are certain of the effects this medication has on you.

Schedule

S4 (prescription required). Available on the general Pharmaceutical Benefits Schedule³.

Common side effects

Like all medications, Baclohexal can cause side effects in some patients. Most of these will occur at the start of treatment or in patients treated with large doses. Most side effects will decrease over time or can be relieved by lowering your dose. Very rarely will the side effects be severe enough to require withdrawal of the medication. Elderly patients and those with other health problems (such as kidney failure) are at greater risk of side effects. The most commonly reported side effects of Baclohexal are listed below but if you experience any symptoms that are worrying you discuss them with your doctor. The following side effects occur in approximately 1-10% of patients:

• Nausea (feeling sick).
• Vomiting.
• Constipation.
• Diarrhoea.
• Rash.
• Increased sweating.
• Hypotension.
• Dry mouth.
• Respiratory depression.
• Myalgia and muscle weakness.
• Drowsiness.
• Dizziness.
• Headache.
• Mental confusion.
• Depression.
• Sleep disturbances.
• Visual disturbances and nystagmus (oscilating eye movements).
• Tinnitus (ringing in the ears).
• Urinary disorders (increased frequency or pain on urination).
• Paradoxical increase in spasticity.

Uncommon side effects

A small number of patients (less than 1%) may experience more serious side effects that require medical attention. The following serious side effects can occur:

• Allergic reactions- If you notice rash, itching or hives on the skin, swelling of the face, lips, tongue or other parts of the body (angioedema), shortness of breath or wheezing see your doctor immediately.
• Respiratory depression- As Baclohexal causes CNS depression, when taken in large doses it can slow breathing and in extreme circumstances may lead to coma.
• Cardiovascular problem- You may notice palpitations, irregular heart beat, ankle swelling or chest pain if this medication affects your heart. These problems occur in less than 1 out of 1000 patients being treated with the drug.
• Psychiatric disturbances.
• Liver problems.
• Urinary retention.

Note that the above lists of side effects are not necessarily exhaustive and other side effects may be discovered as more patients use the drug. However, you should not be too alarmed by these long lists as most patients will not experience any side-effects at all. It is important for you to weigh up the risks and benefits of the drug (with the advice of your doctor) in your individual case to decide if this drug is suited to you.

References

1. Australian Medicines Handbook- 16.9 Baclofen. AMH Pty Ltd. 2006.
2. MIMS online- Prescribing Information. Baclo. MIMS Australia Pty Ltd 2003.
3. Muscle relaxants, Pharmaceutical Benefits Schedule for Health Professionals, Australian Government, Department of Health and Aging 2006. Available at: [URL Link]

For further information talk to your doctor.