Sponsor drugs dosed higher in trials
A newly released study by Sunnybrook researchers has found that in industry-sponsored randomized controlled trials, antidepressants produced by a sponsor company are often dosed higher than nonsponsor comparator drugs. These findings suggest that comparative dose should be considered when interpreting results of sponsored trials.
Studies in which the sponsor drug was dosed higher were significantly more likely to show a positive outcome for that medication, as opposed to studies in which the sponsor drug was not dosed higher.
The team identified several possible explanations for the difference in dosages, including sponsorship bias and the fact that a ‘typical dose' may not have been established. Another possible explanation is that newer antidepressants have fewer or more tolerable side effects than older ones, allowing for higher dosages.
One important issue that arises from these findings is how clinicians use individual studies to decide which medications to use for their patients. "By using a lower dose of the comparator drug in these trials, the results may lead to the false conclusion that a new drug is the same as or better than an optimally dosed comparator drug," says Dr. Mark Sinyor, co-chief resident, psychiatry, Sunnybrook and lead author of the study.
As a result, the researchers suggest "studies should be more transparent about the issue of dosing, and the pharmaceutical industry, sponsors, journal editors, peer reviewers and clinicians need to pay greater attention to this issue," says Dr. Anthony Levitt, psychiatrist-in-chief at Sunnybrook.