Pharmacokinetics/bioavailability of colchicine in healthy male volunteers

In a randomized 2-way cross-over study with twelve healthy male volunteers, two colchicine preparations (tablets, A vs. oral solution, B) were tested. The preparations were administered as single doses of 1 mg; prior to and up to 72 h after medication blood samples were collected and the plasma colchicine concentrations determined. Additionally urine samples were collected at 0-2, 2-4, 4-6, 6-8, 8-10, 10-24, 24-48, 48-72 and 72-96 h intervals. The colchicine plasma and urine concentrations were determined by a newly developed and validated RIA method. The mean area under the plasma concentration-time curve (AUC-1, AUC-3) was calculated as 23.95 +/- 12.10 (AUC-1) and 26.73 +/- 12.75 (AUC-3) h.ng/ml after application of A and 28.01 +/- 14.74 (AUC-1) and 31.57 +/- 16.58 (AUC-3) h.ng/ml after application of B, respectively. Mean peak plasma concentrations of 4.15 +/- 2.35 (A) and 4.88 +/- 3.90 (B) ng/ml were reached at 1.15 +/- 0.38 (A) and 1.13 +/- 0.42 (B) h after application. The mean terminal half-lives accounted for 9.31 +/- 3.98 (A) and 10.57 +/- 5.53 (B) h. The mean total clearance (Cl/F) and volume of distribution (V/F) were found to be 40.12 +/- 20.87 (A) and 46.58 +/- 24.65 (B) l/h and 472.59 +/- 196.46 (A) and 624.89 +/- 304.09 (B) l, respectively. The mean total amount excreted in urine (Ae) was 172.66 +/- 91.51 (A) and 174.85 +/- 63.53 (B) micrograms.(ABSTRACT TRUNCATED AT 250 WORDS)