Loss of response after switching from brand name to generic formulations: three cases and a discussion of key clinical considerations when switching

Int Clin Psychopharmacol. 2010 May;25(3):180-2. doi: 10.1097/YIC.0b013e328337910b.


Generic formulations of medications are marketed as therapeutically equivalent and less expensive than branded ones. Multiple studies and case reports have described relapses and worsening clinical outcome in patients after a switch from a brand name to a generic medication. Recent studies have shown that generics do not always lead to the expected costs savings, reducing the impetus to proceed with compulsory generic switching. We report on three patients who experienced clinical deterioration after commencing the generic formulation of their previous brand name psychotropic medication. We discuss key clinical differences between original and generic formulations of the same medication. The use of bioequivalence as an indicator of therapeutic and clinical equivalence, the lack of appropriate studies comparing generic and brand name medications and differences in excipients are some of the factors that could explain variation in clinical response between generic and brand name medications. Generic switching should be decided on a case-by-case basis with disclosure of potential consequences to the patient.

Publication types

  • Case Reports

MeSH terms

  • Drugs, Generic / therapeutic use*
  • Female
  • Fluoxetine / therapeutic use
  • Humans
  • Male
  • Mianserin / analogs & derivatives
  • Mianserin / therapeutic use
  • Middle Aged
  • Mirtazapine
  • Secondary Prevention
  • Therapeutic Equivalency*
  • Valproic Acid / therapeutic use


  • Drugs, Generic
  • Fluoxetine
  • Mianserin
  • Valproic Acid
  • Mirtazapine