U.S. warns of severe pain with osteoporosis drugs

WASHINGTON (Reuters) - Patients treated with widely used osteoporosis drugs may develop severe and sometimes disabling pain in muscles, joints and bones, U.S. officials said on Monday in an alert highlighting the previously known risk.

The warning applies to Merck & Co Inc’s Fosamax, Roche Holding AG and GlaxoSmithKline PLC’s Boniva, plus all other members of the family known as bisphosphonates.

The risk of severe pain with the drugs has been known for years, but health officials said doctors may be overlooking the medicines as a cause.

Doctors “should consider whether bisphosphonate use might be responsible for severe musculoskeletal pain ... and consider temporary or permanent discontinuation of the drug,” the Food and Drug Administration said in an alert posted on its Web site.

The prescribing instructions for the drugs already mention the risk of severe pain in a list of “precautions” for doctors. Manufacturers said cases of incapacitating pain were uncommon.

The muscle, joint or bone pain “may occur within days, months or years after starting a bisphosphonate,” the FDA said.

Some patients reported the pain was so severe it interfered with normal activities and they required aids for walking.

In some cases, pain disappeared after stopping a bisphosphonate, “whereas others have reported slow or incomplete resolution,” the FDA said.

FDA spokeswoman Susan Cruzan said the agency is reviewing hundreds of reports of pain in bisphosphonate users, noting that prescriptions for the drugs number in the millions. Potential side effects typically are under-reported, she added.

The ongoing FDA review will take about six months, the agency said.

Bisphosphonates are used primarily to increase bone mass and reduce the risk of fractures in patients with osteoporosis, which weakens bones and increases the risk of fractures. Some of the drugs are injected and some are oral pills.

The other bisphosphonates include Actonel, sold by Procter & Gamble and Sanofi-Aventis; Novartis AG’s Zometa, Aredia and Reclast; P&G’s Didronel; and Sanofi’s Skelid. Reclast is sold outside the United States as Aclasta.

Novartis said reports of severe pain were rare among bisphosphonate users. Clinical trials and post-approval reporting for Reclast/Aclasta and Zometa showed less than 1 percent of patients experienced incapacitating muscle, joint or bone pain, the company said in a statement.

Roche and Procter & Gamble said reports of disabling pain were “infrequent”.

Merck said its instructions for Fosamax tell doctors to stop prescribing the drug if severe pain develops. “Most patients had relief of symptoms after stopping treatment,” the company said.

The pain is different from acute pain that some patients develop with fever, chills and other symptoms soon after starting the drugs, the FDA said. That type of pain usually resolves within several days while drug treatment continues.

In October, the FDA disclosed a separate review of whether bisphosphonates may be linked to a dangerously fast heartbeat known as atrial fibrillation. That review could take as long as a year, the agency said at the time.

The new FDA alert was postedhere.

Reporting by Lisa Richwine, editing by Carol Bishopric, Gary Hill