Hormone Replacement Therapy (HRT) Bleeding Risk Examined in New Study

The findings of a new study suggest that women taking hormone replacement therapy (HRT) drugs may face an increased risk of gastrointestinal bleeding. 

Researchers from Massachusetts General Hospital say they found that an increased risks of blood clots associated with HRT, which can raise the risk of heart attacks and strokes, also increase the risk of lower intestinal bleeding. The findings were presented on May 18 at the Digestive Disease Week in Washington, D.C. and have not yet been published or peer reviewed.

The study looked at data on about 74,000 women and compared intestinal bleeding rates between women who used HRT drugs and those who had not.

The results indicate that women currently using popular hormone drugs, like Prempro and Premarin, were 50% more likely to experience some type of gastrointestinal bleeding. Those who had used HRT drugs in the past had a 20% increased risk compared to those who had never used it.

The largest increased risk, however, was linked to ischemic colitis and lower intestinal bleeding. Current HRT users were more than twice as likely to experience those types of gastrointestinal problems than non-users. In addition, the longer a woman used HRT drugs, the more her risk of lower intestinal bleeding increased, the findings suggest.

HRT Cancer Risks

Previously, the primary concerns associated with use of hormone replacement therapy has been the potential risk of breast cancer. In 2002, a study by the Women’s Health Initiative first warned of the risk of breast cancer from hormone replacement therapy.

In 2012, a study using data from the Nurse’s Health Study, found an 88% increase in the risk of breast cancer for women who underwent HRT over a period of 10-15 years. The risk doubled if the women used HRT for 15 to 20 years.

The manufacturers of Prempro, Premarin and other HRT medications have faced thousands of breast cancer lawsuits filed by former users of hormone replacement therapy, which alleged that inadequate warnings were provided about the safety of the medications.

Several juries nationwide have awarded multi-million dollar compensatory damage awards to plaintiffs diagnosed with breast cancer after HRT use, including a number of cases that included punitive damage awards after juries found that drug makers intentionally hid the risks associated with the medications. However, the drug makers have also obtained defense verdicts in a number of cases.

Pfizer agreed to pay out about $1.2 billion to settle 10,000 HRT breast cancer lawsuits in 2012.