Dear Dr. Donohue • What are your feelings about Actonel? There's been talk that it causes bones to break after taking it for five or more years. I have taken it for five years. Should I stay on it? I take calcium and vitamins, and I swim and work out. — E.R.

Dear Dr. Donohue • A friend of a friend was going down a flight of stairs and was three steps from the bottom. She fell and broke her hip. She was told that Fosamax caused the bone to break. I would like your input on this. — B.J.

Answer • The most effective medicines for prevention of broken bones due to osteoporosis are the class of drugs called bisphosphonates. Fosamax (alendronate), Actonel (risedronate), Boniva (ibandronate) and Reclast (zoledronate) are their brand and generic names. Every day, bone is being absorbed and rebuilt. At older ages, absorption outpaces rebuilding, so bones become osteoporotic. Bisphosphonates slow the absorption process. These drugs have been proven to prevent hip fractures from osteoporosis.

A few years ago, it was noted that some women on long-term bisphosphonate treatment were suffering fractures of their thigh bones (femurs) — not the same kind of fractures due to osteoporosis, but fractures of the thigh about midway down the bone It's been suggested that long-term use of bisphosphonates could be responsible for these fractures. Actually, the number of broken thighs allegedly due to bisphosphonates is quite low even in people who have taken the drugs for 10 years.

So what's the upshot? As of March 2010, the Food and Drug Administration has not suggested any change in how bisphosphonates are used or the length of time they're taken. Some experts, however, feel it is wise to take a vacation from these drugs after five or 10 years of use.

This is an issue best addressed by your own doctor, who can assess your risk of suffering from an osteoporosis fracture. If a vacation is suggested, keep taking calcium and vitamin D, and performing weight-bearing exercise like walking.

Dear Dr. Donohue • I am 69 and have just found out that I have a fatty liver. What is the cause? What do I do to get rid of it? — S.J.

Answer • Fatty livers are found in 29 million Americans. The condition is called NAFLD, nonalcoholic fatty liver disease. It produces no symptoms and is not an immediate health danger. It might, however, progress to NASH, nonalcoholic steatohepatitis, which is a health danger. In this condition, the fat irritates the liver cells, which, in turn, can produce liver scarring, cirrhosis and liver failure.

If you are overweight, losing about 5 percent of your current weight should return the liver to normal.

Write Dr. Donohue at P.O. Box 536475, Orlando, Fla. 32853-6475.