Results of the study demonstrated conclusive evidence of drug dose gender gaps from 86 different FDA-approved medications.
Results of a new study published in the journal Biology of Sex Differences showed an association between sex biases in drug dosage trials and the overmedication of women.1
According to the study investigators from UC Berkeley and the University of Chicago, women are more likely than men to experience adverse drug reactions (ADRs) from medications as clinical trials have historically focused on men.1
The study evaluated data from several thousand medical journal articles and found conclusive evidence of drug dose gender gaps from 86 different FDA-approved medications, including but not limited to antidepressants, cardiovascular, and anti-seizure drugs and analgesics.1
“Women have a nearly 2-fold greater risk than men for exhibiting ADRs across all drug classes and are significantly more likely to be hospitalized secondary to an ADR,” study authors wrote. 2
Until the early 1990s, women had been excluded from drug trials for concerns about exposing pregnant women to drugs that risked damage to their fetus. While the US National Institute of Health (NIH) Revitalization Act of 1993 required enrollment of women in federally supported phase 3 clinical trials, the historical remanence of sex biases in medicine and the exclusion of women in drug dose clinical trials remain prevalent factors for gender inequality in pharmacokinetic (PK) study today.2
A 2018 review of 107 NIH funded randomized control trials (RCTs) incorporating both men and women showed that only 26% reported at least 1 outcome by sex or included both sexes as a covariate, whereas 72% failed to include an analysis by sex at all.2
Investigators also found that in upwards of 90% of the cases analyzed, women experienced worse ADRs, including nausea, headache, depression, cognitive deficits, seizures, hallucinations, agitation, and cardiac anomalies.1
Of the 668 medications for the 20 most common treatment regimens in the United States, 46%, or 307, of them show considerable sex differences in ADRs, according to the investigators.2
The study findings argued that doses should be based on milligram/kilogram body weight or titrated to the desired clinical effect rather than a “1-size-fits-all” basis, which leads to higher exposures in women.2
Study authors offered several recommendations to address sex biases and limitation in drug dose gender gaps, including:2
“When it comes to prescribing drugs, a 1-size-fits-all approach, based on male-dominated clinical trials, is not working, and women are getting the short end of the stick,” said study lead author Irving Zucker, PhD, a professor emeritus of psychology and of integrative biology at UC Berkeley.