Drug Interaction Study of Colchicine and Theophylline
Condition: Healthy
Study type: Interventional
Phase: Phase 4

Summary: 
      Colchicine is a supressor of hepatic CYP1A2 and theophylline is a sensitive CYP1A2 probe
      substrate. When the two are co-administered the potential exists for a clinically significant
      drug interaction. This study aims to determine the effect of steady-state colchicine on the
      pharmacokinetics of theophylline administered as a single dose. A secondary goal is to
      evaluate the safety and tolerability of this regimen in healthy volunteers. All study
      subjects will be monitored for adverse events throughout the entire study period.
    

Detailed description: 
      Colchicine is a supressor of hepatic CYP1A2 and theophylline is a sensitive CYP1A2 probe
      substrate. When the two are co-administered the potential exists for a clinically significant
      drug interaction. This study aims to determine the effect of steady-state colchicine on the
      pharmacokinetics of theophylline administered as a single dose. After a fast of at least 10
      hours, thirty healthy, non-smoking, non-obese, non-pregnant adult volunteers between the ages
      of 18 and 45 will be given one dose of 300mg (80mg/15ml concentrate) theophylline
      (theophylline elixir) on Day 1. Fasting will continue for 4 hours after the dose. Blood
      samples will be drawn from all participants before dosing and for 24 hours post-dose on a
      confined basis at times sufficient to adequately determine the pharmacokinetics of
      theophylline. Blood sampling will then continue on a non-confined basis on days 2-3. A four
      day washout period will be completed after the theophylline dose on Day 1 and prior to
      administration of the first colchicine dose on Day 5. Participants will return to the clinic
      on days 5-18 for non-confined dosing of colchicine (1x0.6mg twice daily every 12 hours).
      Administered dosing on these days will not necessarily be in a fasted state.
      Co-administration of a single 300mg dose of theophylline (80mg/15ml) and colchicine (1x0.6mg)
      will occur on the morning of Day 19 following a fast of at least 10 hours. Twelve hours
      later, subjects will receive the last dose of colchicine (1x0.6mg). Blood samples will be
      drawn from all participants before dosing on Day 19 and for 24 hours post-dose on a confined
      basis at times sufficient to adequately determine the pharmacokinetics of theophylline. Blood
      sampling will then continue on a non-confined basis on days 20 and 21. A further goal of this
      study is to evaluate the safety and tolerability of this regimen in healthy volunteers.
      Subjects will be monitored throughout participation in the study for adverse reactions to the
      study drug and/or procedures. Seated blood pressure and pulse will be measured prior to
      dosing and at approximately 1, 2, and 3 hours following drug administration on Days 1, 5
      (after the morning dose) and 19. All adverse events whether elicited by query, spontaneously
      reported, or observed by clinic staff will be evaluated by the Investigator and reported in
      the subject's case report form.
    

Intervention name(s): theophylline; colchicine
Intervention type(s): Drug; Drug
Intervention description(s): 300mg (80mg/15ml elixir); colchicine 0.6mg by mouth twice daily on Days 5-19, co-administered with theophylline 300mg (80mg/15ml) on the morning of Day 19
Other intervention name(s): Elixophyllin®; COLCRYS®
Intervention MeSH terms: Colchicine; Theophylline
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: pharmacokinetics; colchicine; theophylline