A Guide to Osteoporosis Drugs: Bisphosphonates

Institute for Better Bone Health's Guide to Osteoporosis Drugs, part 1: Bisphosphonates (Fosamax® Actonel® Didronel® Boniva® Aclasta®, Reclast®)

woman taking osteoporosis medication

Bisphosphonates are the name of the class of prescriptions drugs for the medical management of osteoporosis.  Nutrition should be the first line of prevention against osteoporosis, but today we turn to powerful drugs before they may really be needed.They are increasingly prescribed for osteopenia - low bone density - as well as full blown osteoporosis, where nutrition may have sufficed.

Understanding how bisphosphonates work and the many products available can help you make an informed decision if these drugs are right for you, or if you have the commitment to preventing or managing osteoporosis naturally.

Bisphosphonates work by slowing the natural process of bone loss.  Bone is constantly going through a process of losing bone mass and building it back up. As we age, bone loss accelerates. It is fundamental to understand this process before starting any medications. Bisphosphonates may help maintain or improve bone density, which may slow the progression of osteoporosis. If you have already been diagnosed with osteoporosis, taking bisphosphonates may reduce the risk of fracturing your weak bones.  Bisphosphonates are deposited on the surface of bone and work by decreasing the activity of osteoclasts, the cells that strip away bone during the bone remodeling process.  The osteoclasts undergo apoptosis, which is the technical term for premature cell death.


Who should take osteoporosis drugs?

This is a controversial subject even among physicians.  The National Osteoporosis Foundation Guidelines for Osteoporosis Management advises bisphosphonates for postmenopausal women and men age 50 and older if they have one or more of the following:

1. A hip or spine fracture (identified by your doctor or found on vertebral imaging)

2. A  T-score ≤ -2.5 at the femoral neck, total hip or lumbar spine

3. Low bone mass (T-score between -1.0 and -2.5 at the femoral neck or lumbar spine) AND a 10-year probability of a hip fracture ≥3% OR a 10-year probability of a major osteoporosis-related fracture ≥20%, based on World Health Organization's FRAX tool.

Basically,  men and women over 50 who have low bone density and have had a bone fracture are  most likely to benefit from prescription medicines for osteoporosis, because they have the highest risk for more fractures.

Most physicians now recommend that patients who take osteoporosis drugs also supplement.  Numerous studies indicate that women taking Fosamax® and other brand name osteoporosis medications almost always require additional vitamin D supplementation, in addition to other nutrients.


Types of Bisphosphonates and Risks

Oral bisphosphonates include: alendronate (Fosamax®), risedronate (Actonel®), Etidronate (Didronel®), and ibandronate (Boniva®).Zolendronate (Aclasta®, Reclast®) is an intravenous form of bisphosphonates, although some of the oral types can also be given intravenously.

Generally, it is recommended to take these on an empty stomach with 8 ounces of water, half an hour before any food, drinks or other medicines. Sitting or standing for 30 to 60 minutes after taking bisphosphonates is also recommended to help avoid heartburn or indigestion.

A major problem with bisphosphonates is that approximately half of the people who are treated will stop taking the medicine within a year. This problem has been reported whether the medicine is taken once a week, or once a month. The most common complaints include inconvenience, indigestion, nausea, heartburn, or irritation of the lining of the throat or stomach. Serious complications are rare although some can be major, such as osteonecrosis of the jaw, where the bone in the jaw has poor circulation. This increases the risk of serious infections that are difficult to treat after tooth extraction. This occurs approximately once in 10,000 patients including some otherwise healthy patients. However, a study of this condition found that nine out of ten cases of osteonecrosis of the jaw occurred following intravenous zolendronate treatment, and in patients with cancer, mainly one type of cancer called multiple myeloma. In spite of this concern, studies show that bisphosphonate treatment decreases 2-5 year mortality rates by more than 10%, especially in older, frailer individuals. Some of this improved life expectancy is attributed to fewer hip fractures, which have serious complications.

Another risk are ‘atypical’ fractures - usually stress fractures and fractures just below the hip. Bone is constantly suffering small injury and repairing it. These atypical fractures may develop because the bone can no longer repair microscopic damage that accumulates over a period of years. Atypical fractures are  painful and more difficult to treat than other types of broken bones -  and much slower  to heal.   Orthopedic surgeons are improving the methods to treat these types of fractures, but are concerned about their connection to bisphosphonate use.

Another consideration might be to stop taking bisphosphonates after 5 years, because the benefits continue for several years after a break from these medicines might give bone a chance to repair microdamages.


Do bisphosphonates work?   

In women with osteoporosis who have had a fracture, bisphosphonates decrease the risk of a second fracture. However, the best available evidence concludes that the benefits are significantly less for preventing that first fracture. Bisphosphonates work about the same as calcium and vitamin D to prevent fractures in women with low bone mineral density, who have never had a fragility fracture. 

Doctors use the term fragility fracture to refer to any broken bone that’s caused by a fall from a standing height or less. Many women with low bone density never break a bone. And low bone mineral density is only one factor of bone health.

In summary, bisphosphonates are most likely to benefit women with osteoporosis who have already had one or more fractures. The benefits may also outweigh the risks for women with osteoporosis who also have one or risk factors: a family history of osteoporosis, very poor diet, unhealthy lifestyle choices, and an inability to tolerate supplements.

Continue the series with Part 2 : Hormone Replacement Therapy

Leave a Reply