Lamotrix (Tablets) Instructions for Use

ATC Code

N03AX09 (Lamotrigine)

Active Substance

Lamotrigine (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Anticonvulsant drug

Pharmacotherapeutic Group

Anticonvulsant agent

Pharmacological Action

Anticonvulsant. The mechanism of action is associated with an effect on voltage-gated sodium channels of the presynaptic membrane.

This leads to a decrease in the release of mediators, primarily glutamate, an excitatory amino acid that plays an important role in the formation of epileptic discharges in the brain, into the synaptic cleft.

Pharmacokinetics

After oral administration, Lamotrigine is rapidly and completely absorbed from the gastrointestinal tract.

C_max in plasma is reached in approximately 2.5 hours. Plasma protein binding is 55%.

It undergoes intensive metabolism to form the main metabolite, the N-glucuronide.

T_1/2 in adults averages 29 hours.

It is excreted by the kidneys mainly in the form of a metabolite; about 8% of the active substance is excreted unchanged.

T_1/2 in children is shorter than in adults.

Indications

Partial and generalized tonic-clonic seizures (more often in cases of resistance to treatment with other anticonvulsants).

ICD codes

Dosage Regimen

Tablets

When taken orally for adults and children over 12 years of age, the initial single dose is 25-50 mg, maintenance doses are 100-200 mg/day.

In rare cases, doses of 500-700 mg/day may be required.

For children aged 2 to 12 years, the initial dose is 0.2-2 mg/kg/day, the maintenance dose is 1-15 mg/kg/day.

Maximum daily dose for children aged 2 to 12 years, depending on the treatment regimen used, is 200-400 mg.

The frequency of administration, intervals between doses when increasing the dose depend on the treatment regimen used, the patient’s response to the treatment.

Adverse Reactions

From the nervous system headache, dizziness, drowsiness, sleep disorders, feeling of fatigue, aggressiveness, confusion.

From the digestive system nausea, liver function disorders.

From the hematopoietic system leukopenia, thrombocytopenia.

Allergic reactions skin rash (usually maculopapular), angioedema, Stevens-Johnson syndrome, toxic epidermal necrolysis, lymphadenopathy.

Contraindications

Severe liver dysfunction, hypersensitivity to lamotrigine.

Use in Pregnancy and Lactation

Clinical data on the safety of lamotrigine use during pregnancy and lactation are insufficient.

When deciding on the need for use during pregnancy, the expected benefit of therapy for the mother and the potential risk to the fetus should be compared.

Preliminary data show that Lamotrigine penetrates into breast milk at a concentration of 40-45% of the plasma concentration.

No adverse effects were noted in a small number of breastfed infants whose mothers received Lamotrigine.

Use in Hepatic Impairment

Contraindicated in severe liver dysfunction.

Use in Renal Impairment

Use with caution in patients with renal failure.

Pediatric Use

Lamotrigine should not be used in children under 2 years of age.

Geriatric Use

Lamotrigine should not be used in elderly patients.

Special Precautions

Use with caution in patients with renal failure.

Lamotrigine should not be used in elderly patients.

If severe skin allergic reactions appear, the use of lamotrigine should be discontinued.

Abrupt withdrawal of lamotrigine may increase the manifestations of epilepsy, so it is necessary to gradually discontinue treatment, reducing the dose over 2 weeks.

When used concomitantly with carbamazepine, dizziness, diplopia, ataxia, visual disturbances, and nausea are possible. These phenomena usually disappear when the dose of carbamazepine is reduced.

Lamotrigine should not be used in children under 2 years of age.

Effect on ability to drive vehicles and mechanisms

During treatment, a slowdown in the speed of psychomotor reactions is observed. This should be taken into account by persons engaged in potentially hazardous activities that require increased attention and rapid psychomotor reactions.

Drug Interactions

With simultaneous use with anticonvulsants – inducers of liver metabolism (including phenytoin, carbamazepine, phenobarbital, primidone), the metabolism of lamotrigine is accelerated.

With simultaneous use of lamotrigine and carbamazepine or phenytoin, the T_1/2 of lamotrigine decreases.

There are reports of dizziness, ataxia, diplopia, blurred vision and nausea in patients taking carbamazepine after starting treatment with lamotrigine.

Due to the inhibition of liver microsomal enzymes under the influence of sodium valproate, with simultaneous use, the metabolism of lamotrigine slows down, the T_1/2 of lamotrigine increases.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.