Lamotrigina Teva (Lamotrigine)

Lamotrigine is an anticonvulsant indicated for several seizure disorders and for mood stabilization in bipolar disorder.

• Partial (focal) seizures: Decreases occurrence of focal onset seizures with or without secondary generalisation.
• Generalized tonic‑clonic seizures: Lowers the risk of convulsive seizures in patients with generalized epilepsy.
• Bipolar disorder (maintenance therapy): Helps maintain mood stability and prevent recurrence of depressive or manic episodes.
• Adjunctive therapy for epilepsy: Added to existing antiepileptic regimens to improve seizure control when monotherapy is insufficient.

• Lamotrigine inhibits voltage‑gated sodium channels, stabilising neuronal membranes and reducing the release of excitatory neurotransmitters such as glutamate. The drug preferentially binds to the inactivated state of the channel, prolonging the refractory period and limiting high‑frequency firing. This action also modulates calcium‑dependent release of other neurotransmitters, contributing to its efficacy in both seizure control and mood stabilization.

Lamotrigine may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Skin rash: mild erythema or itching on trunk or limbs.
• Headache: transient mild to moderate headache, often resolves without treatment.
• Dizziness: light‑headed sensation, especially on standing.
• Nausea: mild gastrointestinal upset, sometimes with loss of appetite.
• Fatigue: feeling of tiredness or reduced energy during daily activities.
• Blurred vision: temporary visual disturbance that improves with continued therapy.

Serious or Rare Side Effects

• Stevens‑Johnson syndrome: severe skin reaction with blistering and possible systemic complications.
• Aseptic meningitis: fever, neck stiffness, headache and photophobia indicating meninges inflammation without infection.
• Blood dyscrasias: agranulocytosis or aplastic anemia with low blood counts and infection risk.
• Liver injury: elevated liver enzymes indicating hepatic stress, may progress to hepatitis.
• Hypersensitivity reactions: fever, eosinophilia, rash and systemic symptoms requiring immediate evaluation.

When prescribing lamotrigine, clinicians should consider several precautionary measures to minimise risks.

• Initiate therapy at low dose: start with a low daily dose and increase gradually to reduce rash risk.
• Monitor skin reactions: watch for any rash or skin changes, especially during the first weeks.
• Assess hepatic function: evaluate liver enzymes before starting and periodically during treatment.
• Avoid abrupt discontinuation: taper the dose gradually to prevent seizure recurrence.
• Store at ambient temperature: keep tablets below 25 °C in the original packaging, protected from moisture.

Lamotrigine may interact with other medicines, altering its plasma concentration or increasing adverse effect risk.

Major Interactions (Avoid)

• Valproic acid: can increase lamotrigine levels up to tenfold, requiring dose reduction and careful monitoring.
• Carbamazepine: induces metabolism and may lower lamotrigine concentrations, potentially reducing efficacy.
• Rifampin: strong enzyme inducer that can markedly lower lamotrigine concentrations, possibly reducing seizure control.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: estrogen‑containing pills can decrease lamotrigine levels, possibly necessitating dose adjustment.
• Phenobarbital: moderate enzyme inducer that may modestly reduce lamotrigine exposure.
• Serotonergic agents: concurrent use may increase risk of serotonin syndrome, requiring clinical vigilance.
• Warfarin: potential interaction affecting anticoagulation; monitor INR closely when co‑administered.
• SSRIs: may increase incidence of skin rash when combined with lamotrigine.