(HealthDay News) — Up to one-third of antidepressants are prescribed for pain, insomnia, migraine, or other unapproved uses, but just 16 percent of those off-label prescriptions are supported by strong research, according to a study published online Feb. 21 in The BMJ.
The new findings stem from an analysis of 106,850 antidepressant prescriptions issued in Quebec, Canada, between 2003 and 2015. They were written by 174 Quebec doctors. According to the researchers, trazodone for insomnia was the most common off-label use for antidepressants. In terms of class of drugs, tricyclic antidepressants like amitriptyline were the most likely to be prescribed off-label. Selective-serotonin reuptake inhibitors were less likely to be used off-label.
The researchers found that, overall, 29.3 percent of all antidepressant prescriptions were written for an off-label indication. They also found that 44.6 percent of the alternative drugs lacked any strong research backing up the effectiveness of the intended off-label purpose. Another 39.6 percent lacked evidence for the medicine at hand, but did have strong evidence supporting use of a similar drug in the same class for the intended off-label usage. Just 15.9 percent of all off-label prescriptions were found to be supported by strong research.
Lead author Jenna Wong, a doctoral candidate in epidemiology, biostatistics, and occupational health at McGill University in Montreal, described the findings as in line with the findings of prior investigations. Wong told HealthDay that she hopes the findings raise awareness among doctors. “Some physicians may not be aware that certain off-label antidepressant uses are not evidence-based, especially if the broader community of physicians prescribes antidepressants for these off-label uses so frequently that it seems like the norm,” she said.