Lamitor, tablets 50 mg 30 pcs

Lamitor blocks potential-dependent sodium channels. Causes block of impulse discharges in neuronal culture, inhibits excessive release of glutamate (an amino acid that plays a key role in the generation of epileptic seizures) along with inhibition of glutamate-induced effector impulses.

Pharmacokinetics

Absorption

Lamotrigine is rapidly and completely absorbed from the GI tract after oral administration. Cmax in plasma is observed 2.5±1.5 hours after oral administration. Time to reach Cmax is slightly longer when taking the drug after meal, but the degree of absorption remains unchanged. Pharmacokinetics is linear up to 450 mg, the maximum single dose that has been studied. There is significant individual variation in Cmax values of the drug, but individual concentrations vary very little.

Distribution

The binding to plasma proteins is approximately 55%.

Metabolism

Metabolized in the liver with the formation of predominantly glucuronides.

Elimination

The T1/2 in healthy adults is 24-35 h.

The average clearance values in healthy subjects are 39±14 ml/min.

Lamotrigine is excreted in the urine as glucuronides. Less than 10% is excreted unchanged in the urine. Only 2% of metabolic products are excreted with the feces.

Pharmacokinetics in special clinical cases

The T1/2 of lamotrigine is highly dependent on concomitant drug therapy.

The T1/2 of lamotrigine is reduced to 14 h when combined with drugs that induce cytochrome P450 isoenzyme activity, such as carbamazepine and phenytoin, and increases to about 70 h on average when combined with sodium valproate.

The T1/2 of lamotrigine in children is generally shorter than in adults. The T1/2 in children is approximately 7 h when taken with drugs that induce isoenzyme activity, such as carbamazepine, phenytoin, phenobarbital and primidone. T1/2 is increased up to 45-55 hours when combined with sodium valproate.

Studies of lamotrigine pharmacokinetics in single doses in patients with renal disease indicate that pharmacokinetic parameters change slightly, but concentrations of the main metabolite as glucuronide increase almost 8-fold due to decreased renal clearance.

Indications

Lamitor is recommended as monotherapy and adjunctive therapy for adults and children over 12 years of age:

Active ingredient

Composition

1 tablet contains lamotrigine 25 mg.

How to take, the dosage

The starting dose of Lamitor for adults and children over 12 years of age who do not take sodium valproate but who take other antiepileptic isoenzyme-inducing drugs is 50 mg once daily for the first 2 weeks and 100 mg/day (in 2 doses) for the next 2 weeks. Then the dose should be increased to 200-400 mg/day (in 2 doses).

The starting dose of Lamitor for patients taking sodium valproate in combination with other isoenzyme-inducing antiepileptic drugs is 25 mg every other day for the first 2 weeks and then 25 mg once daily for the next 2 weeks. Then the dose should be increased until optimal therapeutic effect is achieved. The maintenance dose is 100-200 mg (1 or 2 doses).

The starting dose of Lamitor for children from 2 to 12 years old not taking sodium valproate but taking other antiepileptic isoenzyme-inducing drugs is 2 mg/kg/day (in 2 doses) for the first 2 weeks and 5 mg/kg/day (in 2 doses) for the next 2 weeks. The maintenance dose is 5-15 mg/kg/day (in 2 doses).

The starting dose of Lamitor for children taking sodium valproate in combination with other isoenzyme-inducing antiepileptic drugs is 0.2 mg/kg 1 time/day for the first 2 weeks, then 0.5 mg/kg 1 time/day for the next 2 weeks. Then the dose should be increased until optimal therapeutic effect is achieved. The maintenance dose is 1-5 mg/kg (1 or 2 doses).

Interaction

Simultaneous use with antiepileptic drugs inducing hepatic isoenzymes (phenytoin, carbamazepine, phenobarbital, primidone) increases Lamitor metabolism, which may require increasing its dose.

Sodium valproate, which competes with lamotrigine against liver metabolizing isoenzymes, inhibits its metabolism. There is no evidence that Lamitor can induce or inhibit liver isoenzymes that metabolize other drugs. Lamitor can induce its own metabolism, but this effect is very small and does not cause serious clinical manifestations.

While changes in plasma concentrations of other antiepileptic drugs have been noted in some patients, controlled studies have not confirmed the effect of Lamitor on plasma levels of concomitant antiepileptic drugs. In vitro studies indicate that Lamitor does not compete with other antiepileptic drugs for plasma protein binding sites.

Special Instructions

There is limited information on the use of Lamitor in elderly patients. Therefore, caution should be exercised when prescribing the drug in this category of patients.

If the dose of Lamitor is exceeded, a skin rash may occur (in this case, the drug should be discontinued).

In some cases, the drug may cause a severe skin rash (including Stevens-Johnson syndrome). These reactions develop more often in children. Lamitor should be discontinued at the first sign of a rash. The risk of these complications is increased when Lamitor is prescribed concomitantly with sodium valproate and if the dose of Lamitor used exceeds the recommended initial and maximum daily dose.

The drug should be discontinued immediately if a skin rash develops.

When using Lamitor, symptoms of hypersensitivity may develop (in some cases up to death), such as fever, malaise, cold symptoms, drowsiness, lymphadenopathy, facial edema, and in very rare cases, liver dysfunction, hematopoiesis (leukopenia and thrombocytopenia). In most patients, these symptoms disappear after discontinuation of Lamitor.

If rash, chills, cold symptoms, drowsiness, worsening seizure control occur during use (especially in the first month), liver function tests, renal function tests, and blood clotting should be monitored.

If Lamitor is abruptly withdrawn, seizures may become more frequent. The dose of Lamitor should be reduced gradually over 2 weeks.

In patients with impaired renal function, accumulation of the metabolite as glucuronide should be expected in the terminal stage of the disease. Therefore, caution should be exercised when prescribing in these patients.

Impact on driving and operating machinery

The ability to drive motor vehicles and operate moving machinery while taking Lamitor is decided on an individual basis taking into account the clinical situation.

Contraindications

Hypatic disorders

Contraindicated in severe hepatic impairment.

The use in impaired renal function

In patients with impaired renal function in the terminal stage of the disease, accumulation of the metabolite in the form of glucuronide should be expected. Therefore, caution should be exercised when prescribing in these patients.

Side effects

Side effects reported with Lamitor as monotherapy

CNS side effects: dizziness, headache, somnolence, sleep disturbance, increased fatigue.

Digestive system disorders: nausea.

Allergic reactions: maculopapular skin rash (2%), most often observed in the first 4 weeks after the start of treatment and disappears after discontinuation of the drug. In some cases – Stevens-Johnson syndrome, angioneurotic edema, toxic epidermal necrolysis.

Side effects when using Lamitor as adjunctive therapy to standard antiepileptic drugs

CNS side effects: dizziness, headache, somnolence, impaired balance, increased fatigue, irritability, aggressiveness, tremor, confusion.

Visual organs: diplopia, visual acuity disorders.

Hematopoietic system disorders: neutropenia, leukopenia.

Digestive system disorders: nausea, vomiting, dyspeptic symptoms.

Overdose

Symptoms: nystagmus, ataxia, dizziness, drowsiness, headache, nausea, unconsciousness, coma.

Treatment: gastric lavage, administration of activated charcoal. If necessary, symptomatic therapy is carried out.

Pregnancy use

The drug should not be administered during pregnancy and lactation unless the expected benefits of therapy for the mother exceed the potential risk to the fetus and child.

Periatric use

The starting dose of Lamitor for children from 2 to 12 years old who do not take sodium valproate but who take other antiepileptic isoenzyme-inducing drugs is 2 mg/kg/day (in 2 doses) for the first 2 weeks and 5 mg/kg/day (in 2 doses) for the next 2 weeks. The maintenance dose is 5-15 mg/kg/day (in 2 doses).

The starting dose of Lamitor for children taking sodium valproate in combination with other isoenzyme-inducing antiepileptic drugs is 0.2 mg/kg 1 time/day for the first 2 weeks, then 0.5 mg/kg 1 time/day for the next 2 weeks. Then the dose should be increased until optimal therapeutic effect is achieved. The maintenance dose is 1-5 mg/kg (1 or 2 doses).

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