Dutch sildenafil trial ‘immediately stopped’ due to baby deaths

25-Jul-2018 - Last updated on 25-Jul-2018 at 14:41 GMT

(Image: Getty/Wavebreakmedia)

Researchers have halted a clinical trial testing sildenafil citrate – the active ingredient in Pfizer’s Viagra – in pregnant women, following reports of baby deaths.

A clinical trial in the Netherlands exploring the use of sildenafil in pregnant women, whose babies had severe, early-onset foetal growth restriction due to placental insufficiency, has been immediately halted in the Netherlands.

Blood vessel dilator sildenafil is the active ingredient in Pfizer’s off-patent erectile dysfunction drug, Viagra. However, the Dutch study was investigator-initiated, and Pfizer has no involvement in the trial, a Pfizer spokesperson told us.

According to investigator Amsterdam University Medical Centre (UMC), “An interim analysis by Amsterdam UMC, location AMC [Academic Medical Centre], showed that sildenafil may be detrimental to the baby after birth.”

“The chance of a disease of the blood vessels of the lungs appears to be greater and the chance of death after birth seems to have increased. All adverse effects occurred after birth. For the mothers, the drug had no adverse effect,” a spokesperson told us.

Of the 93 women who took sildenafil in the trail, 19 babies died – including 11 due to a possible lung disease thought to cause a form of high blood pressure in the lungs. 90 women partook in a placebo arm, in which nine babies died. None of these babies had developed the lung disease. Nine babies across the two groups developed the lung disease, but did not die.

“Based on these findings, the study was stopped immediately,” the UMC spokesperson added.

The study was initiated in 2015, and conducted at 11 hospitals across the Netherlands. The Medical Ethical Committee and the Committee for Research on Humans had both approved the trial, we were told.