Lamicet 25

Indications

Lamotrigine is used to treat epilepsy, including focal (partial) seizures, generalised tonic-clonic seizures and seizures linked to Lennox-Gastaut syndrome, either alone or with other antiepileptic medicines. It is also used in adults with bipolar disorder to help prevent episodes of depression.

How It Works

Lamotrigine blocks sodium channels on nerve cells, which steadies the nerve cell membrane. This reduces the release of excitatory chemicals such as glutamate, which can trigger seizures when nerve cells fire too much. The same calming effect on brain signalling is thought to help stabilise mood in bipolar disorder.

Dosage and Administration

Lamotrigine must be started at a low dose and increased slowly over several weeks, exactly as your doctor prescribes, to lower the risk of a serious skin rash. The schedule depends on age, the condition and whether you take Valproate or enzyme-inducing medicines. Swallow tablets with water; dispersible tablets can be chewed or mixed in a little water. Take it at the same times each day. If you stop for more than a few days, do not restart at your old dose: ask your doctor, as you may need to build up again. Do not stop suddenly, as seizures may return.

Interactions

• Valproate roughly doubles Lamotrigine levels, so much lower doses are used and rash risk is higher.
• Carbamazepine, Phenytoin, Phenobarbital, Primidone, Rifampicin and some HIV medicines (such as Lopinavir with Ritonavir) lower Lamotrigine levels.
• Oestrogen-containing contraceptive pills lower Lamotrigine levels; seizure control may change when starting or stopping the pill. Lamotrigine may slightly reduce the effect of some progestogen contraceptives.
• Other medicines that affect folate, such as Methotrexate or Trimethoprim, should be used with care.

Contraindications

• Allergy to Lamotrigine, or a previous serious rash with Lamotrigine.

Side Effects

Common side effects include headache, dizziness, double or blurred vision, unsteadiness, drowsiness or trouble sleeping, nausea, tremor, tiredness, irritability and mild rash.

Serious effects include severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), mostly in the first 8 weeks, especially in children, with Valproate, or when doses are increased too fast. Rarely, a serious immune reaction (haemophagocytic lymphohistiocytosis), liver problems, blood disorders, aseptic meningitis, heart rhythm problems in people with heart disease, and thoughts of self-harm can occur.

Get urgent medical help if you develop any rash, especially with fever, blisters, peeling skin, mouth or eye sores; swollen glands with fever; yellow skin or eyes; unusual bruising or bleeding; severe headache with stiff neck; worsening seizures; or thoughts of harming yourself.

Pregnancy and Lactation

Lamotrigine is considered one of the lower-risk antiepileptic medicines in pregnancy, but any risk must be discussed with your doctor before you try to conceive. Do not stop it on your own, as uncontrolled seizures can harm both mother and baby. Levels usually fall during pregnancy and rise after birth, so blood levels and doses may need checking. Folic acid is advised before and during pregnancy. Lamotrigine passes into breast milk; breastfeeding is often possible, but watch the baby for rash, drowsiness or poor feeding and follow medical advice.

Precautions and Warnings

Tell your doctor about any previous rash with an antiepileptic, kidney or liver disease, heart rhythm problems, or depression. Patients and carers should watch for mood changes. It can cause dizziness and double vision; do not drive or operate machinery until you know how it affects you, and follow local driving rules for epilepsy. Make sure you receive the same type of Lamotrigine product each time.

Overdose

Overdose may cause severe dizziness, unsteadiness, rapid eye movements, headache, vomiting, fits, heart rhythm problems and coma. Seek emergency medical help immediately.

Therapeutic Class

Antiepileptic (anticonvulsant), phenyltriazine; mood stabiliser.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.