Pharmacy Daily | Quit-smoking drugs likely safe in pregnancy

QUIT-SMOKING medicines such as nicotine patches and varenicline do not increase the risk of major birth defects in babies, according to new research from the National Drug and Alcohol Research Centre (NDARC), UNSW Sydney.

The research data found no evidence that infants exposed to these medicines have higher rates of major congenital malformations.

"Considering the devastating consequences of smoking on both mother and baby, our results should reassure pregnant women who need help quitting smoking," said Dr Duong Tran, an NDARC Research Fellow and first author.

"These findings are also helpful for healthcare providers when discussing the benefits and risks of smoking cessation therapies with patients, and better support women to make informed choices about quitting during pregnancy."

There are currently three quit-smoking medicines available through the Pharmaceutical Benefits Scheme - nicotine replacement therapy (NRT), varenicline and bupropion - that are known to be safe and effective in the general population.

However, the lack of clear evidence for their safety in pregnancy means that many clinical guidelines for pregnancy have recommended caution when using NRT and advised against varenicline and bupropion.

The large multinational study compared 13,000 newborns - of whom 9,300 were exposed to NRT, 3,000 to varenicline, and 1,000 to bupropion - and their risk of birth defects with babies born to women who smoked in early pregnancy but did not use these therapies.

Overall, they found no evidence of an increased risk of major birth defects of any type among babies born to women who used these medicines compared with those who smoked in early pregnancy but did not use them.

"Our study is the largest of its kind to date and provides high-quality evidence on the safety of quit-smoking medications in pregnancy, thanks to the international collaboration and innovative analysis of routinely collected data," Dr Tran said.

"Pregnant women are typically excluded from clinical trials due to medico-legal, ethical and other reasons; hence, observational studies like ours are essential to filling in the knowledge gaps and for guiding healthcare decisions."

The authors pointed out there is not enough data on bupropion to make a definitive finding.

They also cautioned that the study timeframe does not discount the risk of long-term functional concerns such as neurodevelopmental disorders.

Read the full paper HERE. KB