Pharmacokinetic and Exploratory Electrocardiogram (ECG) Study

This study will characterize the pharmacokinetics of colchicine after an oral dosing regimen of 4.8 mg over 6 hours. In addition it will compare the electrocardiogram (ECG) changes, if any, from this dosing regimen to that of a single dose of moxifloxacin 400 mg, a positive control for the corrected QT interval (QTc) prolongation.

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.

Eligibility Criteria:
Inclusion Criteria:

* Healthy adults 18-55 years of age, non smoking and non-pregnant, weighing at least 55kg and within 15% of ideal body weight, with no significant EKG changes

Exclusion Criteria:

* Pregnant or lactating
* Test positive at screening for human immunodeficiency virus (HIV), hepatitis B surface antigen (HbsAg), or hepatitis C virus (HCV)
* Recent (2-year) history or evidence of alcoholism or drug abuse
* History or presence of significant cardiovascular, pulmonary, hepatic, renal, haematological, gastrointestinal, endocrine, immunologic, dermatologic, neurological, or psychiatric disease
* History or family history of congenital long QT syndrome (LQTS) or sudden death possibly related to LQTS
* Subjects who have used any drugs or substances known to inhibit or induce cytochrome (CYP) P450 enzymes and/or P-glycoprotein (P-gp) within 30 days prior to the first dose and throughout the study