Side Effects of Actonel, Fosamax Linked to Eye Problems: Study

People using Fosamax, Actonel and similar osteoporosis drugs for the first time could be at an increased risk of inflammatory eye diseases that may result in permanent vision loss, according to the findings of new research. 

In a study published online Monday by the Canadian Medical Association Journal (CMAJ), researchers from the Child and Family Research Institute and the University of British Columbia examined the risk of inflammatory eye problems from side effects of Fosamax, Actonel and the entire family of drugs known as bisphosphonates .

Researchers conducted a retrospective cohort study involving British Columbia residents from 2000 to 2007, and found that use of the popular osteoporosis drugs may significantly increase the risk of the rare eye disease uveitis and scleritis during the first 30 to 90 days of use.

Fosamax (alendronate sodium) and Actonel (risedronate) are among the most commonly used bisphosphonate medications in the United States. The oral medications are often prescribed to strengthen the bones and reduce the risk of fractures associated with osteoporosis.

The study compared nearly 11,000 first-time users of oral bisphophonates to nearly 1 million non-users. Researchers found that if 10,000 people were followed for one year, then 63 of them that took Fosamax or a similar drug would develop scleritis, compared to only 36 people among 10,000 who did not take the drug. Similarly, there would be 29 incidents of uveitis for every 10,000 person years among those who took one of the osteoporosis drugs, compared to only 20 among those who did not.

Uveitis occurs when the middle layer of the eye, known as the uvea, begins to swell and become irritated. Symptoms include blurred vision, seeing dark spots, eye pain, redness of the eye and sensitivity to light. The uvea delivers blood to the retina. It can last for weeks and is usually mild, but can result in permanent vision loss.

Scleritis is an inflammation of the white outer wall of the eye. Symptoms can include blurred vision, severe eye pain, red patches in the whites of the eye, painful sensitivity to light and tearing of the eye. It is easily treated with corticosteroids but if left untreated it can cause perforation of the eyeball, leading to permanent vision loss.

In recent years, a number of side effects have been associated with Fosamax and other bisphosphonates, such as an increased risk of low-trauma femur fractures and a rare jaw bone condition, known as osteonecrosis of the jaw. Merck & Co., the manufacturer of Fosamax, currently faces hundreds of product liability lawsuits alleging that they failed to adequately warn risk of these side effects.