Plasma tenoxicam concentrations after single and multiple oral doses.
The pharmacokinetics of single- and multiple-dose administration of tenoxicam 20 mg were evaluated in 8 healthy males. Maximum plasma concentration (Cmax) after the first dose was 2.76 +/- 0.48 micrograms/ml (mean +/- s.d.) and the time to reach Cmax (Tmax) was 5.0 +/- 3.0 h. The area under the plasma concentration-time curve (AUC0-infinity) after a single administration of tenoxicam was 242.5 +/- 73.5 micrograms x h/ml. The elimination half-life (t1/2) was 66.3 +/- 15.8 h and the plasma concentration at 24 hours after dosing (Cmin) was 1.84 +/- 0.33 micrograms/ml. Steady-state plasma concentrations of tenoxicam were virtually reached after 10 consecutive daily doses. At steady-state, Cmax averaged 13.63 +/- 3.33 micrograms/ml and Tmax remained 5.0 +/- 3.0 hours. AUC within a dosing interval at steady-state was 262.2 +/- 67.0 micrograms x h/ml, Cminss was 9.67 +/- 3.25 micrograms/ml, and t1/2 averaged 74.2 +/- 13.3 h. The average fluctuation during multiple-dose administration was 26.8 +/- 8.0% and the accumulation ratio was 5.82 +/- 0.60. Steady-state pharmacokinetic parameters predicted from the first-dose data slightly underestimated observed values, but the results supported the assumption of linear pharmacokinetics during multiple-dose tenoxicam administration.
Crevoisier
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C
Pharma Clinical Research Department, F. Hoffmann-La Roche & Co., Basle, Switzerland.
Heizmann
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P
Forgo
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Dubach
U C
UC
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008297:Male; D010894:Piroxicam / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010894:Piroxicam; C032801:tenoxicam