Studies on concentration-time profiles of nimodipine enantiomers following intravenous and oral administration of nimodipine in patients with subarachnoid hemorrhage.
After i.v. and oral administration of nimodipine the concentration-time profiles of the drug and its enantiomers were studied in seven patients with subarachnoid hemorrhage. Concentrations of nimodipine, (+)-(R)-, and (-)-(S)-nimodipine were analyzed using a new stereoselective high-performance liquid chromatographic method. During the first 3 h after oral administration the concentrations of (+)-(R)- and (-)-(S)-nimodipine were significantly different, the (-)-(S)-enantiomer being found in much lesser concentrations compared to the (+)-(R)-enantiomer. The results indicate that if uptake from the gastrointestinal system is equal for the two enantiomers, then (-)-(S)-nimodipine is metabolized at a much faster rate compared to (+)-(R)-nimodipine after oral administration of the drug in patients with subarachnoid bleeding. After i.v. administration; no significant differences between the concentrations of the (-)-(S) and the (+)-(R) isomers were demonstrated.
Wanner-Olsen
H
H
Department of Anaestesiology, Aarhus Kommunehospital, DK-8000 Aarhus C, Denmark.
Gaarskaer
F B
FB
Mikkelsen
E O
EO
Jakobsen
P
P
Voldby
B
B
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009553:Nimodipine / Q000008:administration & dosage* / Q000097:blood* / Q000737:chemistry; D013237:Stereoisomerism; D013345:Subarachnoid Hemorrhage / Q000097:blood* / Q000188:drug therapy*; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000097:blood* / Q000737:chemistry
D014665:Vasodilator Agents; D009553:Nimodipine