The Dutch trial meant to study whether sildenafil, the active ingredient in the brand-name drug Viagra, can prevent children from being born with low birth weight has been halted early amid a wave of tragic deaths.
Nearly 100 pregnant women were given the drug during their pregnancy in the trial and 11 babies later died, according to the Amsterdam University’s Academic Medical Center. The deaths are especially frightening, since the drug is seemingly already being given to expectant mothers around the world.
Sildenafil affects the body by dilating blood vessels, making it easier for blood to flow to wherever it’s needed. That attribute has made the drug a successful treatment for erectile dysfunction, but some doctors started speculating it could also help mothers with placentas that don’t easily provide blood (and nutrients) to developing fetuses. The incurable condition, known as intrauterine growth restriction, leads to stunted growth in fetuses that is usually spotted 20 weeks into the pregnancy through an ultrasound. The benefits of maternal sildenafil had earlier been seen in animal trials.
The trial began in 2015 and was originally set to run until 2020. Three-hundred and fifty women were expected to be recruited from 10 hospitals across the Netherlands, with half receiving sildenafil and half given a placebo. As of last week, when the trial was ended by an independent committee, 183 women had taken part, with 93 receiving sildenafil. amsterdam university medical center
Of the babies born to these women, 17 developed lung problems, with 11 dying soon after birth as a result. The rate of health complications and deaths was lower in the control group, with only three children experiencing any similar lung issues and none dying from it. There were 17 other deaths seen during the trial, but these were considered unrelated to the drug’s use and split about equally between the groups. There was also no positive effects on birth weight or other health outcomes in the treatment group. Currently, it’s theorized the drug might have caused some babies to have high blood pressure, which could have restricted blood and oxygen flow to their lungs. The independent committee reviewing the trial found no signs of malfeasance or improper actions taken by the trial researchers.
The Dutch trial results are only the latest to suggest that sildenafil might not be as useful for mothers as thought. The result of a trial in the UK released last year found no beneficial effect of the drug, though it also reported no significant adverse effects. A trial out of New Zealand published in March similarly found no effect on birth weight, though it did suggest a slightly higher survival rate for the children of women who took sildenafil. The unexpected deaths have led to another sildenafil trial in Canada being temporarily shut down.