Pharmacokinetics of carbamazepine in normal man

The bioavailability of commercial carbamazepine talbets with and without meals was compared to a propylene glycol solution respect to extent of absorption in 6 normal humans after a dose of 6 MG/KG. The presence of dose-dependent kinetics within a clinically sigificant range was also investigated. Serum and urine samples were assayed by gal-liquid chromatography (GLC). Carbamazepine is rapidly absorbed from the propylene glycol solution. Eight per cent of the dose was absorbed from the commercial tablet, resulting in therapeutic serum concentrations(30 to 6 mcg/ni). The data were consitent with disolution rate-limited absorption. Mean half-lives ranged from 31 to 35 hr. No dose-dependent kinetics were observed following administration of does of 3. 6. or 9 mg/kg. The fraction of dose abosrbed, the fraction excredted unchanged in urine, the time of maxium serum concentration, and absorption and elimination half-lives appear to be independent of dose. The time course of side effects could not be correlated with serum carbamazepine levels, suggesting that metabolities contributed to side effects.