Amitiza Side Effects During Pregnancy Lead to Call for Stronger Warnings

The prominent consumer advocacy group Public Citizen has filed a petition with the FDA seeking a “black box” warning about the potential side effects of Amitiza for pregnant women, indicating that stronger warnings are necessary about the risk of early child birth and unintended abortions.

The petition was sent to the FDA in early May 2009, asking for the stronger warning on the label, the required distribution of a Medication Guide for all patients indicating the risk of taking the drug while pregnant and a “Dear Doctor” letter to inform healthcare providers about the risk.

“The FDA and drug makers should take every step possible to warn pregnant women and their doctors about the dangers of taking [Amitiza],” said Sidney Wolfe, M.D., director of the Health Research Group at Public Citizen. “The current label is grossly inadequate as it lacks useful information pertaining to the risks of drug-induced abortion in pregnant women who take this drug.”

Amitiza (lubiprostone) is in a new class of medications known as chloride channel activators, which work by causing a release of chloride ions and concomitant fluids in the intestinal track. It was approved by the FDA in January 2006 for treatment of chronic constipation and later approved in 2008 for use on patients with irritable bowel syndrome.

The petition calls for the FDA to require a “black box” warning on Amitiza clearly indicating a risk of premature birth and abortion, and strong wording indicating that the drug should not be used by women who are pregnant or intend to become pregnant while on the medication. Additionally, Public Citizen also charges that the drug seems to have very little actual use against the ailments they were designed to treat.

In the current issue of their Worst Pills newsletter, Public Citizen recommends to readers that Amitiza should not be used at all, as there are “safer and equally or more effective treatments for both chronic constipation and for the constipation variety of irritable bowel syndrome.”

Public Citizen indicates that the drugs makers, Sucampo Pharmaceuticals Inc. and Takeda Pharmaceuticals America, Inc., noted Amitiza side effects on pregnant guinea pigs and monkeys in clinical trials. The trials found that Amitiza caused dose dependent abortions in some guinea pigs, and contractions in others. In monkeys, there were incidents of early child birth and abortion as well.

The group notes that the results were similar to the ulcer drug Cytotec (misoprostol), which works similarly to Amitiza. However, misoprostol has far more stringent labeling, particularly regarding pregnancy.