For over 20 years, Zithromax has been one of the most prescribed antibiotics in the United States and has been used to treat a variety of bacterial infections. Despite its popularity and effectiveness, this drug (known generically as azithromycin) has been linked to several major health complications including liver damage, kidney failure, and skin blisters. It may also be linked to a new potential complication: antibiotic-induced birth defects.

Zithromax is manufactured by Pfizer, and has gained its fame from its short prescription requirement and fast-acting treatment mechanism. Compared to the standard 10-day prescription regime for other antibiotics, Zithromax (also known as Z-Pak and Zmax) only requires five.

Even with the potential Zithromax side effects that patients face, the drug still remains a formidable presence in the pharmaceutical community, gaining more than $450 million in sales in 2011.

Unfortunately, popularity does not exonerate Pfizer from the alleged liability violations the company is facing from patients who claim the antibiotic caused them serious health complications. These side effects have led to a number of Zithromax product liability lawsuits.

Overview: Antibiotic Birth Defects

In a 2009 study published in the Archives of Pediatrics and Adolescent Medicine, researchers found that popular antibiotics used to treat urinary tract infections could cause birth defects.

The study was funded by the Centers for Disease Control and Prevention (CDC), and was led by Dr. Krista Crider. The antibiotic birth defect study was the first large analysis of pregnant women who used antibiotics and the aftermath.

According to the results of the study, birth defects were more likely to occur when mothers used two particular antibiotics: sulfa drugs (like Thiosulfil Forte and Bactrim) and urinary germicides called nitrofurantoins (like Furadantin and Macrobid).

Researchers looked at over 13,000 mothers with infants born with birth defects, along with 5,000 women who lived in the same region who bore healthy infants. These women were interviewed by phone from six weeks to two years after their pregnancies, with researchers identifying women who had or had not been exposed to antibiotics during that time.

From the data gathered, sulfa drugs had been linked to more severe birth defects that affected the brain and heart, and caused the infants to have shorter limbs. As for the infants whose mothers were exposed to nitrofurantoins, they were born with minor heart problems and cleft palate.

While nothing was definitively proven, Dr. Crider stated that additional studies were needed to confirm if there is a risk for antibiotic birth defects.

The purpose of this study was to help determine which antibiotics were safe to prescribe to pregnant women, to reduce risk to the mother and unborn child. Even though Zithromax was not included in the study, major concern has arisen over whether or not pregnant women should be taking any antibiotic while pregnant.

Women who did take Zithromax (azithromycin) while pregnant and had a child with a birth defect may be eligible to file a Zithromax birth defect lawsuit.