Pharmacokinetics of dipotassium chlorazepate in patients after repeated 50 mg oral doses

Abstract

Dipotassium chlorazepate (DPC) was administered to ten patients (five males and five females), aged 18–37 years (mean 27.4), as a once daily dose of 50 mg until a steady state was reached. Plasma concentrations of the main metabolite N-desmethyldiazepam (DMD) were monitored by a high pressure liquid chromatographic (HPLC) method during the medication period and for 5 days after withdrawal of the drug. The plasma half life (t _1/2), the elimination coefficient (K_β), the steady state concentration $\left( {\bar C_{ss} } \right)$, and the apparent volume of distribution (V_β), were calculated at steady state and the mean values ±SEM were 44±5 h, 0.0184±0.0026 h^-1, 1590±163 ng/ml and 1.41 ±0.17 l/kg, respectively. A moderate inter-individual variability was observed. There was no tendency towards dose dependent elimination.