Lamotrigine

Lamotrigine is a powerful anticonvulsant used to treat epileptic seizures.

[1], [2], [3], [4], [5],

Indications Lamotrigine

Among the indications for using the medication:

• generalized or partial forms of seizures (among them spasms of tonic-clonic type, and in addition seizures that develop as a result of Lennox-Gastaut syndrome) - children 12+ years of age, as well as adults for monotherapy of epileptic seizures or as an additional medicine;
• as a means for monotherapy with typical forms of absence;
• as a prophylaxis of mood disorders (such as mania, depression or hypomania, and in addition mixed cases) in patients aged 18+ suffering from manic-depressive psychosis.

[6]

Release form

Produced in the form of tablets in a volume of 25, 50 or 100 mg. One blister contains 10 tablets of medicine. The pack contains 1 or 3 blister plates.

[7], [8], [9]

Pharmacodynamics

The drug helps to stabilize the membranes of neurons, affecting the presynaptic channels of sodium (potential-dependent). In addition, it inhibits the pathological release of 2-aminopentanedioic acid (this amino acid contributes to the development of epileptic seizures) and slows depolarization, which is caused by glutamate.

[10], [11], [12]

Pharmacokinetics

The active substance is completely and rapidly absorbed from the digestive tract. After oral administration, the peak concentration reaches 2.5 hours later. Absorption of the drug slows down if taken with food, but this does not affect its effectiveness. The vessels circulate in the protein-bound form (maximum 55% of the absorbed substance). The coefficient of cleansing in plasma is approximately 0.2-1.2 ml / min per kilogram of weight, and the distribution volume is 0.9-1.3 l / kg.

Metabolism occurs in the liver due to the glucuronation process. The half-life in adults is approximately 24-35 hours, in children it is usually shorter. The speed of this period is strongly influenced by other medicines taken with lamotrigine.

Excretion occurs mainly through the kidneys (in the form of glucuronides, and less than 10% are excreted unchanged), and about 2% - by the intestine.

[13], [14]

Dosing and administration

Intended for oral administration. Frequency and duration of administration, as well as dosage, are determined by the doctor individually for each patient. Children 12+ years and adults are usually prescribed 25-200 mg twice a day (the maximum allowed daily dose is 700 mg); at the age of 2-12 years - 2-15 mg / kg twice a day (the maximum permissible daily dose is 400 mg).

[20], [21], [22]

Use Lamotrigine during pregnancy

When pregnant, the drug should not be used, except in situations where the potential benefit exceeds the risk of developing negative effects on the fetus. According to the FDA rating, the medicine is classified as C.

Contraindications

Among the contraindications: lactation period, individual intolerance of the elements of the medicine, as well as children younger than 2 years.

[15], [16],

Side effects Lamotrigine

Among the side effects are possible such reactions:

• organs of the National Assembly: dizziness with headaches, insomnia or vice versa drowsiness, severe fatigue, and in addition aggressiveness, anxiety and irritability. Diplopia, tremor, confusion, problems with balance, loss of visual acuity and conjunctivitis can also occur;
• organs of the hematopoietic system: leukopenia or thrombocytopenia;
• Gastrointestinal organs: vomiting with nausea;
• Allergies: a skin rash (mostly maculopapular, developing during the first 8 weeks of treatment) that disappears after the drug is withdrawn, hypersensitivity (swelling on the face, fever, hematologic disorders (anemia) and liver disorders, as well as lymphadenopathy and, in rare cases cases, ICE or MES). Occasionally, the development of Lyell's syndromes or Stevens-Johnson is possible.

[17], [18], [19]

Overdose

Among the manifestations of an overdose: sensation of drowsiness, headaches and dizziness, besides nystagmus with ataxia, vomiting, and coma.

To eliminate symptoms, hospitalization of the patient is necessary. Gastric lavage procedures are performed, activated charcoal is administered, and symptomatic and supportive treatment is also provided.

[23], [24], [25], [26],

Interactions with other drugs

Valproates are competitive blockers of liver enzymes, as a result of which the lamotrigine glucuronization process is suppressed, and the metabolic rate decreases and the average half-life time (up to 70 hours) increases.

Anticonvulsants that induce metabolic hepatic enzymes (such as phenytoin with carbamazepine, as well as phenobarbital with primidone), and in addition paracetamol - increase the rate of glucuronization of lamotrigine, as well as its metabolism. In the case of combined administration, the average half-life of the active ingredient decreases approximately 2-fold (to 14 hours). There are reports of the occurrence of side effects in the central nervous system - ataxia, dizziness, nausea, loss of visual acuity, diplopia (with carbamazepine during lamotrigine treatment). Symptoms disappear after a decrease in the dosage of carbamazepine.

When combined with combined OC, which contains ethinylestradiol (30 mcg), as well as levonorgestrel (150 mcg), the index of the lamotrigine cleansing factor is increased (approximately 2-fold). As a result, AUC and peak concentrations decrease (an average of 52, and 39%, respectively). During the week during which the medication is not taken, the concentration of the active substance in the plasma increases (before the use of a new dose, it is approximately 2 times higher than that observed during active treatment).

Rifampicin increases the index of the lamotrigine cleansing factor and, in addition, decreases its half-life - by stimulating the hepatic enzymes responsible for the glucuronidation process. Patients taking rifampicin as an additional remedy, it is necessary to prescribe lamotrigine according to a scheme that is recommended for its joint administration with stimulant drugs glucuronization.

[27], [28], [29], [30], [31]

Storage conditions

Keep the medication required in a place that is closed from sunlight and access to children. Temperature conditions - no more than 25 ° С.

[32], [33]

Shelf life

Lamotrigine is allowed to be used for 3 years after the manufacture of the medicine.

[34], [35], [36]