Review Drug

Brand name Tegretol

Used in the following combined preparations None

GENERAL INFORMATION

Chemically related to the tricyclic antidepressants, carbamazepine reduces the likelihood of fits caused by abnormal nerve signals in the brain. Doctors have used it in the long-term treatment of epilepsy for many years. This drug is
considered particularly suitable for treating children since side effects are less of a problem compared to some of the other drugs used in the treatment of epilepsy.

Carbamazepine is also prescribed to relieve the intermittent severe pain caused by damage to the cranial nerves – for example, in trigeminal neuralgia.
Carbamazepine is also occasionally prescribed to treat certain psychological or behavioural disorders.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken

Tablets, chewable tablets, liquid, suppositories.

Frequency and timing of doses

1-4 x daily.

Adult dosage range

Epilepsy 100-1,200mg daily. Pain relief 100-1,600mg daily. Psychiatric disorders 400-1,600mg daily.

Onset of effect

Within 4 hours.

Diet advice

None.

Storage

Keep in a closed container in a cool, dry place out of the reach of children.

Missed dose

Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug

Do not stop the drug without consulting your doctor; symptoms may recur.

Exceeding the dose

An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause tremor, convulsions, and coma. Notify your doctor.

Duration of action

12-24 hours.

POSSIBLE ADVERSE EFFECTS

Most people experience very few adverse effects with this drug, but when blood levels get too high, adverse effects are common and the dose may need to be reduced. To avoid side effects, carbamazepine therapy is usually commenced at a low dose and is gradually increased until the required blood level of the drug is achieved.

INTERACTIONS

Anticoagulant drugs Carbamazepine may reduce the effect of anticoagulant drugs.
The anticoagulant dose may need to be adjusted accordingly.

Oral contraceptives Carbamazepine may reduce the effectiveness of oral contraceptives. An alternative form of contraception may be necessary. Discuss with your doctor.

Cimetidine may increase the effects of carbamazepine.

Verapamil and co-proxamol These may increase the effects of carbamazepine.

Antibiotics and isoniazid Antibiotics, such as clarithromycin and erythromycin, and isoniazid may increase blood levels of carbamazepine.

QUICK REFERENCE

Drug group Anticonvulsant drug and antipsychotic drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

You have long-term liver or kidney problems.

You have heart problems.

You are taking other medications.

Pregnancy

May be associated with abnormalities in the unborn baby. Folic acid supplements recommended. Discuss with your doctor.

Breast-feeding

The drug passes into the breast milk, but at normal doses adverse effects on the baby are unlikely. Discuss with your doctor.

Infants and children

Reduced dose necessary.

Over 60

May cause confused or agitated behaviour in the elderly. Reduced dose may be
necessary.

Driving and hazardous work

Discuss with your doctor. Your underlying condition, as well as the possibility of reduced alertness while taking carbamazepine may make such activities inadvisable.

Alcohol

Avoid. Alcohol may increase the sedative effects of this drug.

PROLONGED USE

There is a slight risk of changes in liver function or blood abnormalities occurring during prolonged use.

Monitoring Periodic blood tests are usually performed to monitor levels of the drug in the body, the composition of the blood, and liver function.