Lamotrigine is indicated for:Epilepsy-combination therapy in patients aged 2 years and older: partial-onset seizures primary generalized tonic-clonic seizures generalized seizures of Lennox-Gastaut syndrome Epilepsy-monotherapy in patients aged 16 years and older.Adults with Bipolar Disorder.

Primary anti-epileptic drugs

Lamotrigine controls epileptic seizures by inhibiting voltage-sensitive sodium channels, thereby stabilizes neuronal membranes and consequently inhibits presynaptic excitatory neurotransmitter (e.g., glutamate and aspartate) release.

Monotherapy of seizures (adult and child over 16 years): Initially 25 mg once daily for 14 days, then 50 mg once daily for further 14 days, then increased by maximum 50 mg/day every 7-14 days; usual maintenance dose 225-375 mg/day in 1-2 divided doses.Adjunctive therapy of seizures with Valproate: Adult and child over 12 years: Initially 25 mg on alternate days for 14 days, then 25 mg once daily for further 14 days, thereafter increased by maximum 25-50 mg/day every 7-14 days; usual maintenance, 100-200 mg/day in 1-2 divided doses. Child 2-12 years: Initially 150 mcg/kg/day in 1-2 divided doses for 14 days (those weighing under 13 kg may receive 2 mg on alternate days for first 14 days), then 300 mcg/kg/day in 1-2 divided doses for further 14 days, thereafter increased by maximum 300 mcg/kg/day every 7-14 days; usual maintenance 1-3 mg/kg/day in 1-2 divided doses. Adjunctive therapy of seizures (with enzyme inducing drugs e.g., Carbamazepine, Phenytoin, Phenobarbital, or Primidone) without Valproate: Adult and child over 12 years: Initially 50 mg once daily for 14 days, then 50 mg twice daily for further 14 days, thereafter increased by maximum 100 mg/day in every 7-14 days; usual maintenance 300-500 mg daily in 2 divided doses. Child 2-12 years: Initially 600 mcg/kg/day in 2 divided doses for 14 days, then 1.2 mg/kg/day in 2 divided doses for further 14 days, thereafter increased by maximum 1.2 mg/kg/day in every 7-14 days; usual maintenance 5-15 mg/kg/day in 2 divided doses (maximum 400 mg/day in 2 divided doses). Monotherapy therapy of bipolar disorder (without enzyme inducing Drugs) without Valproate: Adult over 18 years: Initially 25 mg once daily for 14 days, then 50 mg once daily for further 14 days, then 100 mg once daily for further 7 days; usual maintenance dose 200 mg once daily; maximum 200 mg daily. Adjunctive therapy of bipolar disorder with valproate: Adult over 18 years: Initially 25 mg on alternate days for 14 days, then 25 mg once daily for further 14 days, then 50 mg once daily for further 7 days; usual maintenance dose 100 mg daily; maximum 100 mg daily. Adjunctive therapy of bipolar disorder (with enzyme inducing drugs with enzyme inducing drugs e.g., Carbamazepine, Phenytoin, Phenobarbital, or Primidone) without Valproate: Adult over 18 years: Initially 50 mg once daily for 14 days, then 50 mg twice daily for further 14 days, then 100 mg twice daily for further 7 days, then 150 mg twice daily for further 7 days; usual maintenance 200 mg twice daily

Lamotrigine interacts with Oral contraceptives, Atazanavir/ritonavir, Carbamazepine, Levetiracetam, Lithium, Lopinavir/ritonavir , Olanzapine, Phenobarbital/primidone , Phenytoin, Pregabalin etc.

Hypersensitivity (e.g., rash, angioedema, acute urticaria, extensive pruritus, mucosal ulceration) to the drug or its ingredients.

Common side effects of Lamotrigine include-dizziness, tremor, headache, rash, blurred vision, fever, lack of coordination, abdominal pain, infections, sleepiness, back pain, vomiting, diarrhea, tiredness, insomnia, dry mouth, stuffy nose, sore throat.

Pregnancy category C. Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.Nursing Mothers: Lamotrigine is present in milk from lactating women taking Lamotrigine.

Serious skin rashes, Blood Dyscrasias, Suicidal Behavior, Aseptic Meningitis can occur in both adult and pediatric population.

Overdose has resulted in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma, and intraventricular conduction delay.

Store below 30°C. Protect from light and moisture. Keep out of the reach of children.

Primary anti-epileptic drugs

The exact mechanism of action of lamotrigine is not fully elucidated, as it may exert cellular activities that contribute to its efficacy in a range of conditions. Although chemically unrelated, lamotrigine actions resemble those of phenytoin and carbamazepine, inhibiting voltage-sensitive sodium channels, stabilizing neuronal membranes, thereby modulating the release of presynaptic excitatory neurotransmitters.Lamotrigine likely acts by inhibiting sodium currents by selective binding to the inactive sodium channel, suppressing the release of the excitatory amino acid, glutamate. The mechanism of action of lamotrigine in reducing anticonvulsant activity is likely the same in managing bipolar disorder. Studies on lamotrigine have identified its binding to sodium channels in a fashion similar to local anesthetics, which could explain the demonstrated clinical benefit of lamotrigine in some neuropathic pain states.Lamotrigine displays binding properties to several different receptors. In laboratory binding assays, it demonstrates weak inhibitory effect on the serotonin 5-HT3 receptor. Lamotrigine also weakly binds to Adenosine A1/A2 receptors, α1/α2/β adrenergic receptors, dopamine D1/D2 receptors, GABA A/B receptors, histamine H1 receptors, κ-opioid receptor (KOR), mACh receptors and serotonin 5-HT2 receptors with an IC50>100 µM. Weak inhibitory effects were observed at sigma opioid receptors. An in vivo study revealed evidence that lamotrigine inhibits Cav2.3 (R-type) calcium currents, which may also contribute to its anticonvulsant effects.

Pregnancy Category C. Lamotrigine is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Lamotrigine, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.