Lamotrigine: Price, Dosage & Where to Buy

Lamotrigine is an antiepileptic medicine used to treat epilepsy, including partial-onset seizures and certain generalised seizures. It is also used for maintenance treatment of bipolar disorder to delay further mood episodes after an acute episode has been treated with standard therapy. Lamotrigine requires a prescription in the United Kingdom and is available in several oral formulations.

Lamotrigine is indicated alongside other epilepsy medicines for partial-onset seizures, primary generalised tonic-clonic seizures and generalised seizures associated with Lennox-Gastaut syndrome in patients aged 2 years and older. Partial-onset seizures begin in a particular area of the brain. The label also describes conversion to lamotrigine alone in patients aged 16 years and older with partial-onset seizures who are receiving carbamazepine, phenytoin, phenobarbital, primidone or valproate as their single antiepileptic medicine.

For bipolar disorder, lamotrigine is a maintenance treatment intended to delay subsequent episodes of depression, mania, hypomania or mixed mood symptoms after standard treatment of an acute episode. It is not recommended for acute manic or mixed episodes, and effectiveness in treating acute mood episodes has not been established.

Antiepileptic medicines reduce the tendency of nerve cells in the brain to produce excessive electrical activity. A general mechanism involves stabilising channels that control the movement of electrically charged particles across nerve cell membranes. This helps limit repeated, rapid nerve signals and can reduce the release of chemical messengers that stimulate other nerve cells.

These effects help explain seizure control. The way such effects contribute to maintenance treatment of bipolar disorder is less clearly understood than their role in reducing abnormal electrical activity.

The label lists oral tablets in strengths of 25 mg, 50 mg, 100 mg, 150 mg, 200 mg, 250 mg and 300 mg, and an oral suspension of 10 mg/mL. The label lists chewable tablets of 5 mg and 25 mg, tablets for suspension of 2 mg, 5 mg and 25 mg, and orally disintegrating tablets of 25 mg, 50 mg, 100 mg and 200 mg. The label lists extended-release tablets of 25 mg, 50 mg, 100 mg, 200 mg, 250 mg and 300 mg.

Dosing depends on the indication, age and other medicines, rather than a single starting schedule. Recommended initial dosing and subsequent increases must not be exceeded because of rash risk. Maintenance treatment may need adjustment when oestrogen-containing products are started or stopped.

Moderate or severe liver impairment requires dosage adjustment, while reduced maintenance dosing may be effective in significant kidney impairment. Restarting treatment after an interruption requires assessment of whether the initial dosing schedule is needed again.

A missed dose can interrupt regular treatment. General pharmacy advice is to avoid doubling a dose to compensate and to ask a pharmacist if the timing is uncertain.

After a longer interruption, lamotrigine may need to be restarted using an initial dosing schedule because of rash risk. A prescriber should assess restarting rather than assuming the previous regimen remains appropriate.

Pregnancy registries and epidemiological studies have not detected an increased overall frequency of major congenital malformations or a consistent pattern of malformations with lamotrigine exposure. Animal studies found developmental toxicity, so these human findings do not establish absence of risk. Poorly controlled seizures can harm the mother and baby, and antiepileptic treatment should not be abruptly discontinued during pregnancy.

Lamotrigine concentrations may fall during pregnancy and return towards pre-pregnancy levels after delivery, potentially requiring treatment adjustment. The label does not specify breastfeeding information here; discuss pregnancy or breastfeeding with a doctor or pharmacist.

The label specifies storage at 20°C to 25°C in a dry place. Keep the medicine out of the reach of children. A blister that is torn or broken should not be used.