Chronic use of protease inhibitors may be associated with avascular necrosis of bones, say US researchers.
Presenting the results of a study at the annual meeting of the American Orthopaedic Association on June 16, Dr Guy Paiement (professor of orthopaedic surgery, University of California, San Francisco) reported a link between protease inhibitors and avascular necrosis of the femoral head.
The study evaluated 18 patients with HIV who were diagnosed with avascular necrosis between 1991-99. Of the 18, 11 were using protease inhibitors. Of these 11 patients, 10 had no other risk factors (such as alcohol consumption or steroid use) for the condition. Of the seven not using protease inhibitors, six had other risk factors for avascular necrosis.
The researchers suggest a possible mechanism for the development of avascular necrosis related to the effects of protease inhibitors on fat metabolism.
Increased levels of fat in the circulation could lead to fat molecules blocking the amount of blood that can feed into the bone tissue, resulting in bone death, said Professor Paiement.