FDA Reviews Evidence on Painkiller Risks in Pregnancy

January 12, 2015

Pregnant patients concerned about taking painkillers for their rheumatic disease? Here's a quick summary of why the FDA thinks risks for miscarriage, neural tube defects and ADHD aren't yet well documented.

The FDA has reviewed the evidence about the safety of painkillers during pregnancy from large clinical trials, to address "concerns arising from recent reporrs."

Citing conflicting evidence and limitations in study design, the agency makes no new recommendations, advising physicians only to follow prescribing guidelines.

The FDA reminds physicians that NSAIDs are contraindicted in the third trimester due to the risk of premature closure of the ductus arteriosus.

Its Drug Safety Communication on the subject makes the following major points:

•    Prescription nonsteroidal anti-inflammatory drugs (NSAIDs) and miscarriage: Three retrospective case-control studies (total n>100,000) showed adjusted odds ratios (aORs) ranging from 2.4 to 7.0. They overlooked so many possible confounding factors that it's impossible to judge their validity. Two prospective observational studies (n-3,835) had opposing results (adjusted hazard ratios of 1.8 and 0.9).

•    Opioids and birth defects:  Two retrospective case-control studies (n>28,000) showing aORs of 2.0 and 2.2 for neural tube defects had potential for selection bias and relied on patient interviews to document opioid use. (Would mothers of infants with birth defects be more likely to remember using these painkillers?)

•    Acetaminophen and attention deficit/hyperactivity disorder (ADHD):  Prospective studies (n>100,000) showing risk increases from 13% to 37% lacked information about general health and acetaminophen dosage and as well as clinical diagnoses of ADHD.