A Silver Bullet?

A trial in the new American Journal of Psychiatry found that adding metformin to a regimen of atypical antipsychotic medications stopped children from continuing to gain weight while taking the atypical antipsychotics. So can we now just shrug off concerns about the skyrocketing use of atypical antipsychotic use among kids? Here’s part of what an accompanying editorial by Towbin had to say:

“The study does not address the long-term safety of metformin treatment or whether weight loss is sustained. This is important because vulnerable children may require metformin treatment as long as they continue to take atypical antipsychotics, typically for symptoms that last many years. Metformin, a relative of pheformin, has long-term side effects that lead to B₁₂ and folate deficiency (7) in up to 30% of chronic users. Fatal lactic acidosis with metformin has been seen in the context of uncompensated congestive heart disease, acute renal insufficiency, and liver disease (8) and may emerge with chronic use of nonsteroidal anti-inflammatory drugs (9). It is reassuring that these conditions are relatively rare in children and adolescents. In addition, the study did not compare pharmacological treatment to specific, targeted treatments for dietary control that combine dietary counseling, exercise, and behavioral intervention, which have been shown to be effective in adults (10, 11). Just as patients in the metformin trial missed doses of medication, behavioral programs also have problems with patients failing to adhere to their diet or exercise schedules on occasion…

Finally, it is noteworthy for our field that such a high proportion of the cohort had diagnoses or symptoms for which there is no clear FDA-approved indication for treatment with atypical antipsychotics (12, 13)—17 (44%) of the 39 had "attentional disorders," and seven (18%) had oppositional defiant disorder.”

My View: Doubtless, many will take this as a blessing to continue the use of atypicals for everything (including ADHD and oppositional defiant disorder, apparently) now that a “cure” for weight gain has been discovered. Don’t get me wrong – if metformin is really helpful, GREAT! But I’ll await longer-term studies before I jump on this bandwagon.