Review Drug.

Brand name Lamictal

Used in the following combined preparations None

General Information

Lamotrigine, introduced in 1993, is an anticonvulsant drug that is prescribed, either alone or in combination with other anticonvulsants, for the treatment of epilepsy. The drug acts by restoring the balance between excitatory and inhibitory neurotransmitters in the brain. Lamotrigine may be less sedating than older anticonvulsants, and there is no need for blood tests to determine the level of the drug in the blood.

Lamotrigine may cause a number of minor adverse effects (see below), most of which will respond to an adjustment in dosage. Unlike many of the older anticonvulsant drugs, lamotrigine does not interfere with the action of the oral contraceptive pill.

Quick Reference

Drug group Anticonvulsant drug

Overdose danger rating Medium
Dependence rating Low
Prescription needed Yes
Available as generic No

Information for Users

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

How taken

Tablets, dispersible tablets.

Frequency and timing of doses

1-2 x daily.

Adult dosage range

100-400mg (100-200mg if given together with sodium valproate) daily (maintenance dose). Smaller doses are used at the start of treatment.

Onset of effect

Approximately 5 days at a constant dose.

Duration of action

Up to 24 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 taking the drug without consulting your doctor, who will supervise a gradual reduction in dosage over a period of about two weeks. Abrupt cessation increases the risk of rebound fits.

Exceeding the dose

An occasional unintentional extra dose is unlikely to be a cause for concern. Large overdoses may cause sedation, double vision, loss of muscular coordination, nausea, and vomiting. Contact your doctor immediately.

Possible Adverse Effects
Serious adverse effects are rare. The most common side effects are skin rash, nausea, headache, tiredness, insomnia, blurred or double vision, dizziness, agitation, confusion, and lack of muscle coordination. These will
respond to a dose reduction, and a rash is less likely if the treatment is started at a low dose (25mg), increasing gradually over about 4 weeks. If sore throat or persistent or unusual bruising occur, call your doctor immediately.

Special Precautions

Be sure to tell your doctor if:

You have long-term liver or kidney problems.

You suffer from thalassaemia.

You are taking any other medication.

Pregnancy

Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding

Safety in breast-feeding not established. Discuss with your doctor.

Infants and children

Not recommended under 2 years. Not recommended as a single therapy under 12 years. Doses may be relatively higher than adult doses due to increased metabolism.

Over 60s

The dose may need to be reduced.
Driving and hazardous work

Your underlying condition, in addition to the possibility of sedation, dizziness, and vision disturbances while taking lamotrigine, may make such activities inadvisable. Discuss with your doctor.

Alcohol

Alcohol may increase the adverse effects of this drug.

Prolonged Use

No special problems known.

INTERACTIONS

Sodium valproate increases and prolongs the effectiveness of lamotrigine. A reduced dose of lamotrigine is used if the two are prescribed together.

Carbamazepine may reduce lamotrigine blood levels, but lamotrigine may increase the side effects of carbamazepine.

Phenytoin and phenobarbitone may decrease blood levels of lamotrigine so a higher dose of lamotrigine may be needed.