Official Title: “Examination of the Pharmacokinetic Properties of Two Generic Antidepressants and Their Respective Brand Preparations in Healthy Male Volunteers”

Generic medications should be the equivalent of brand medications with the exception of their price. Before a generic medication is introduced, its bioequivalence within a window of 80 to 125% of the original has to be demonstrated. There are reports that this criterion is not always followed in post-marketed periods. Such investigations were triggered by the observation that some patients previously stable on original medications relapsed when switched to a presumable equivalent generic. Several factors could account for this problem.

Given reports of such problems occurring with the antidepressants citalopram and venlafaxine, some pharmacokinetic properties of specific brands of generics and the originals will be examined for these two medications. Twelve healthy male volunteers will participate in this crossover study. It is anticipated that there will be significant differences emerging between the two formulations given the clinical reports of patients deteriorating when switched from the original to the generic preparations.

Study Type: Interventional

Study Design: Treatment, Randomized, Open Label, Crossover Assignment, Bio-equivalence Study

Study Primary Completion Date: July 2008

Intervention(s) in this Clinical Trial

• Drug: Venlafaxine
  • NOVO-Venlafaxine XR 75 mg (NOVOPHARM, Generic)
• Drug: Gen-Citalopram
  • Gen-Citalopram 40 mg (Genpharm, Generic)
• Drug: Effexor XR
  • Effexor XR 75 mg (Wyeth Pharmaceuticals, Brand Name)
• Drug: Celexa
  • Celexa 40 mg (Lundbeck, Brand Name)

Arms, Groups and Cohorts in this Clinical Trial

• Active Comparator: 1
  • Crossover Effexor / NOVO-Venlafaxine Examination of the bioequivalence of Effexor (Wyeth Pharmaceuticals) and NOVO-Venlafaxine (NOVOPHARM). Both drugs will be given at the dose of 75 mg/day (one capsule per day) for 4 consecutive days. A washout period (corresponding to 10 half-life of the active metabolite desmethylvenlafaxine) will be respected after receiving each medication.
• Active Comparator: 2
  • Crossover Celexa/Gen-citalopram Examination of the bioequivalence of Celexa (Lundbeck, Brand Name) and Gen-Citalopram (Genpharm, Generic). Both drugs will be given at the dose of 40 mg/day (one tablet per day) for 8 consecutive days. A washout period (corresponding to 10 half-life of citalopram) will be respected after receiving each medication.

Primary Measures

• Blood levels of drugs and their metabolite (when appropriate) will be evaluated for both the generic and the brand name medication.
  • Time Frame: 1 month
    Safety Issue?: No

Inclusion Criteria:

• Healthy volunteers (absence of diseases: psychiatric, physical, neurological, metabolic,...)

Exclusion Criteria:

• Psychiatric disorder
• Hepatic disease
• Renal disease
• Gastrointestinal disease
• Hematological disease
• Smokers
• Physical and/or neurological disease
• Positive urine drug screen
• Abnormal blood pressure
• Abnormal urine/blood analysis (sodium, potassium, chloride, creatinine, urea, ALT, AST, total protein, glucose, and TSH)

Gender Eligibility for this Clinical Trial: Male

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 50 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: Accepts Healthy Volunteers

Lead Sponsor: University of Ottawa

Overall Clinical Trial Officials and Contacts

Franck Chenu, Ph.D. Study Director University of Ottawa Institute of Mental Health Research  

Information obtained from ClinicalTrials.gov on July 02, 2009

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00676039

Study ID Number: REB-2007024

ClinicalTrials.gov Identifier: NCT00676039

Health Authority: Canada: Health Canada