Pharmacokinetic and Exploratory Electrocardiogram (ECG) Study

• Maximum Plasma Concentration (Cmax) [ Time Frame: serial pharmacokinetic blood samples collected pre-dose and 1 (prior to second dose), 3 (prior to fourth dose), 6 (prior to final dose), 6.17, 6.33, 6.5, 6.75, 7, 7.25, 7.5, 7.75, 8, 10, 12, 23, 36, 48, 72 and 96 hours post-dose ] [ Designated as safety issue: No ]
  
• Area Under the Concentration Versus Time Curve From Time 0 to Time t [AUC(0-t)] [ Time Frame: serial pharmacokinetic blood samples collected pre-dose and 1 (prior to second dose), 3 (prior to fourth dose), 6 (prior to final dose), 6.17, 6.33, 6.5, 6.75, 7, 7.25, 7.5, 7.75, 8, 10, 12, 23, 36, 48, 72 and 96 hours post-dose ] [ Designated as safety issue: No ]
  
• Area Under the Concentration Versus Time Curve From Time 0 Extrapolated to Infinity [AUC(0-∞)] [ Time Frame: serial pharmacokinetic blood samples collected pre-dose and 1 (prior to second dose), 3 (prior to fourth dose), 6 (prior to final dose), 6.17, 6.33, 6.5, 6.75, 7, 7.25, 7.5, 7.75, 8, 10, 12, 23, 36, 48, 72 and 96 hours post-dose ] [ Designated as safety issue: No ]
  

• Electrocardiogram (ECG) Evaluation of the QTcF Interval (Colchicine) [ Time Frame: 24 hours - measured 0.5 hr prior to first dose (baseline), then 1, 3, 6, 7, 8, 10, 12, and 23 hours after first dose ] [ Designated as safety issue: Yes ]
  
• Electrocardiogram (ECG) Evaluation of the QTcF Interval (Moxifloxacin) [ Time Frame: 24 hours - measured 0.5 hr prior to dose (baseline), then 1, 3, 6, 7, 8, 10, 12, and 23 hours after dose ] [ Designated as safety issue: Yes ]
  

This study will characterize the pharmacokinetics of colchicine after an oral dosing regimen of 4.8 mg over 6 hours. In addition, it will determine whether or not there is a trend toward effect of this high dose regimen on the electrocardiogram (ECG), mainly the corrected QT interval (QTc), via comparison to a 400 mg dose of moxifloxacin, a positive control for QTc prolongation. Eighteen healthy, non-smoking, non-obese, non-pregnant adults between the ages of 18 to 55 years of age will be randomized in a double blind fashion to either the colchicine or moxifloxacin treatment groups. On the day prior to the study (Day -1), subjects will receive colchicine and moxifloxacin placebos according to the same schedule and conditions as will be present during the study, and baseline ECG's will be determined by 24 hour 12-lead Holter monitoring. On Day 1, after a minimum 10 hour overnight fast, subjects enrolled in the colchicine treatment group (N=15) will receive two 0.6 mg capsules (plus one dose moxifloxacin placebo) followed by an additional 0.6 mg colchicine dose (plus one dose moxifloxacin placebo) every hour for 6 additional doses; subjects in the moxifloxacin treatment group will receive placebo doses matching the colchicine treatment group over the first 5 hours, then 400 mg moxifloxacin (plus one dose colchicine placebo) at the 6 hour point. Fasting will continue for 4 hours after the first dose at which time a standardized meal will be served. Blood will be drawn from all participants at times sufficient to adequately define the pharmacokinetics of colchicine. During the study, continuous 24-hour ECG monitoring via 12-lead Holter monitor will be performed. Triplicate ECG records will be extracted from 5 minute observation periods throughout the 24 hours post dose. Finally, all study subjects will be monitored for adverse effects throughout the entire study period.