Popular Hyperthyroid Drugs Linked to Birth Defects

Birth defect lawyers at Pintas & Mullins Law Firm highlight a recent study which found that two of the country’s most popular hyperthyroid medications were associated with birth defects when taken in early pregnancy. The drugs studied were propylthiouracil (PTU) and methimazole (MMI).

The study was conducted by researchers in Denmark, who analyzed the country’s national databank of children born with birth defects. The Aalborg University Hospital researchers presented their findings at a meeting with the American Thyroid Association.

Of the two drugs studied, MMI had significantly higher rates of risk (75%) than PTU (50%), though both rates were alarming compared to the general population not taking hyperthyroid drugs. The two types of drugs were also associated with very different types of birth defects: PTU with face and neck abnormalities, and MMI with musculoskeletal problems.

The study examined nearly 850,000 births in Denmark between 1996 and 2008 along with data on birth defects (diagnosed before the child was two years old) from the Danish National Hospital Registry. In total, 564 infants were exposed to PTU and nearly 1,100 were exposed to MMI. Another 159 were exposed to both. The remaining women took the drugs but not while pregnant or never took an antithyroid at all.

They found that infants exposed to both drugs in-utero showed significantly higher risks of birth defects compared with the general population. Fortunately, there were no increased risks for children born to women who took hyperthyroid drugs but not during pregnancy.

As stated, infants exposed to MMI were more likely to have musculoskeletal defects, including higher rates of digestive, urinary, and eye abnormalities along with respiratory and circulatory defects. Conversely, PTU-exposed infants had much higher rates of face and neck abnormalities, followed by urinary, circulatory, digestive, and respiratory defects.

Women with hyperthyroidism who become pregnant face an array of health risks, and are faced with the difficult decision of either ceasing their medication or risking their child’s future health. Hyperthyroidism accelerates the body’s metabolism, causing sudden weight loss, rapid or irregular heartbeats, and nervousness among other symptoms. Knowing this, physicians sometimes recommend that women with severe hyperthyroidism remain on medications because stopping them could cause even more devastating problems to the infant.

The study’s researchers concluded their report with recommendations that clinicians restrict the use of any thyroid drug during pregnancy, however, if treatment is necessary, to prescribe PTU over MMI. It is worth noting that mothers taking a PTU early in pregnancy and eventually switching to MMI did not appear to have a decreased risk of birth defects.

In related news, Nephron Pharmaceuticals recently recalled several lots of its generic Albuterol due to problems with its aseptic processing. The inhalable solution (0.083%) was recalled due to problematic internal monitoring results, and all recalled lots were in 25-count packs. All affected lot numbers can be found here.

Drug recall lawyers at Pintas & Mullins Law Firm will continue to report on dangerous drug recalls, studies, reports, and FDA notices. If you or a loved one took a drug while pregnant and had a child with defects or abnormalities, you may be entitled to significant compensation through a lawsuit against the manufacturer. Our experienced pharmaceutical lawyers have decades of experience in this field, and offer free legal consultations to potential clients in all 50 states.


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