Epitomax decreases the frequency of action potentials characteristic of the neuron in the state of persistent depolarization, indicating that the drug’s blocking effect on sodium channels depends on the state of the neuron. Epitomax potentiates GABA activity against several GABA receptor subtypes (including GABAA receptors) and modulates the activity of GABAA receptors themselves, inhibits kainate activation of kainate/AMPK receptor sensitivity to glutamate and does not affect N-methyl-D-aspartate activity against NMDA receptors. These effects of epitomax are dose-dependent at plasma concentrations of epitomax between 1 μM and 200 μM, with minimal activity between 1 μM and 10 μM.
In addition, Epitomax inhibits the activity of some carboanhydrase isoenzymes, but this effect in Epitomax is weaker than in acetazolamide and does not seem to be the main in the antiepileptic activity of Epitomax.
After oral administration Epitomax is absorbed quickly and effectively. Bioavailability is 81%. Food intake has no clinically significant effect on the bioavailability of Epitomax. Binding to plasma proteins is 13-17%. After a single dose of up to 1.2 g, the average Vd is 0.55-0.8 l/kg. Vd value depends on sex: in women it is about 50% of values observed in men, which is associated with a higher content of adipose tissue in women.
Epitomax pharmacokinetics is linear. Plasma clearance remains constant, with AUC in the dose range of 100 to 400 mg increasing in proportion to the dose. Css in plasma is reached after 4-8 days. After multiple oral doses of 100 mg twice daily, Cmax averages 6.76 mcg/ml. After oral administration, about 20% of the administered dose is metabolized. Six virtually inactive metabolites have been identified in plasma, urine and feces. It is excreted mainly by the kidneys unchanged (70%) and as metabolites. Plasma clearance is 20-30 ml/min. After multiple doses of 50 mg and 100 mg twice daily, the T1/2 of Epitomax from plasma is on average 21 hours.
Epilepsy: as monotherapy agent for initial treatment in patients over 2 years old – partial or primary generalized tonic-clonic seizures; as part of complex therapy in patients over 2 years old – partial or generalized tonic-clonic seizures and seizures against Lennox-Gastaud syndrome. Migraine: prevention of migraine attacks in adults.
The mode of administration and dosage regimen of a particular drug depend on its form of release and other factors. The optimal dosing regimen is determined by the doctor. It is necessary to strictly follow the correspondence of the used dosage form of a particular drug to the indications for use and the dosing regimen.
Individual, depending on the indications, age of the patient, kidney function, and effectiveness of the ongoing therapy.