Problems of Forensic Sciences 2000 Vol. 43 (XLIII) 57-61
PHARMACOKINETIC STUDY OF DEXTROMETHORPHAN WITH URINARY EXCRETION
Heesun CHUNG, Wonkyung YANG, Hwakyung CHOI, Wontack JIN, Sihnyoung SIHN, Youngchan YOO
National Institute of Scientific Investigation, Seoul, Korea
Streszczenie
Because the abuse of Dextromethorphan, a non-narcotic antitussive agent, is very common and characteristic in Korea, the metabolic phenotype of dextromethorphan is studied to understand the disposition of the drug in the Korean population. Firstly, the pharmacokinetic study with urinary excretion in man was performed to obtain the urinary excretion rate constant (K) of the unchanged drug and elimination half-life (t1/2) of the drug. Secondly, the pharmacokinetics of dextromethorphan in rat was studied. After a single 30mgdextromethorphan oral administration to volunteers, dextromethorphan and free dextrorphan concentrations in urine were measured using solid-phase extraction byGCand GC/MS. Urine was collected every 2 h for 8 h, 3–4 times in 24 h and then every 12 h for 72 h. The excretion rate constant of dextromerhophan was 0.056/h. The elimination half-life of dextromethorphan in the body was 6.58 h. Urinary recovery of dextromethorphan ranged from 0.23–0.55% in five subjects over 24 h. The metabolic ratio of free dextrorphan to dextromethorphan varied between subjects. The ratio between dextrorphan/dextromethorphan ranged from 1.6 to 37.3. The plasma concentration of dextromethorphan was determined in five rats after administration of 10 mg/kg of dextromethorphan intravenously. The first order elimination rate constant of dextromethorphan by two compartment model was 0.036 and the value of Vd (l/kg) was 0.66.
Słowa kluczowe
Dextromethorphan; Urinary excretion; Pharmacokinetics.