The pharmacokinetics, metabolism and urinary detection time of caffeine in camels.
The pharmacokinetics of caffeine were determined in 10 camels after an intravenous dose of 2.35 mg kg(-1). The data obtained (median and range) were as follows. The elimination half-life (t(1/2)) was 31.4 (21.2 to 58.9) hours, the steady state volume of distribution (V(SS)) was 0.62 (0.51 to 0.74) litre kg(-1)and the total body clearance (Cl(T)) was 14.7 (8.70 to 19.7) ml kg(-1)per hour. Renal clearance estimated in two camels was 0.62 and 0.34 ml kg(-1)per hour. In vitro plasma protein binding (mean +/-SEM, n = 10) to a concentration of 2 and 8 microg ml(-1)was 36.0 +/- 0.24 and 39.2 +/- 0.36 per cent respectively. Theophylline and theobromine were identified as caffeine metabolites in serum and urine. The terminal elimination half-life of the former, estimated in two camels, was 70. 4 and 124.4 hours. Caffeine could be detected in the urine for 14 days.
Camel Racing Laboratory, Forensic Science Laboratory, Abu Dhabi, United Arab Emirates. iawasfi@emirates.net.ae
I A
IA
Wasfi
N S
NS
Boni
M
M
Elghazali
A A
AA
Abdel Hadi
A M
AM
Almuhrami
I M
IM
Barezaig
N A
NA
Alkatheeri
D000818:Animals; D019540:Area Under Curve; D002110:Caffeine / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics* / Q000652:urine; D002162:Camelus / Q000378:metabolism* / Q000502:physiology; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D006207:Half-Life; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D011485:Protein Binding / Q000502:physiology; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D013805:Theobromine / Q000097:blood / Q000652:urine; D013806:Theophylline / Q000097:blood / Q000652:urine
D002110:Caffeine; D013806:Theophylline; D013805:Theobromine