The effect of an apparent change to a branded or generic medication on drug effectiveness and side effects

Generic medications are associated with reduced perceived effectiveness, increased perceived adverse effects, and increased rates of nonadherence compared with brand-name medications. This study examined the effect of an apparent medication formulation change on subjective and objective measures of medication effectiveness and medication side effects.

Sixty-two university students participated in a study purportedly testing the effectiveness of fast-acting β-blocker medications in reducing preexamination anxiety. All tablets were placebos. In session 1, all participants received a yellow tablet ("Betaprol"). In session 2, participants were randomly allocated to receive Betaprol (no change condition) or a white tablet labeled either as "Novaprol" (branded change condition) or "Generic" (generic change condition). Blood pressure and state anxiety were measured before and after tablet ingestion. Side effects attributed to medication were assessed.

The no change group showed significantly greater decreases in systolic blood pressure (mean [M] [standard deviation] = -7.72 mm Hg, standard error [SE] = 1.45) than the branded change (M = -2.75 mm Hg, SE = 1.44, p = .02) and generic change (M = -3.26 mm Hg, SE = 1.45, p = .03) groups. The no-change group showed significantly greater decreases in state anxiety (M = -1.53, SE = 0.33) than the branded change (M = -0.50, SE = 0.33, p = .03) and generic change (M = -0.52, SE = 0.33, p = .04) groups. Significantly more side effects were attributed to the medication in the generic change (M = 1.83, SE = 0.23) (but not the branded change) condition when compared with the no change condition (M = 0.87, SE = 0.31, p = .03).

Medication formulation change, particularly to generic medication, seems to be associated with reduced subjective and objective measures of medication effectiveness and increased side effects.