There are definite benefits to osteoporosis drugs. People who take osteoporosis drugs, regularly and correctly, reduce their risk of having a fracture by about one-third. This is particularly true in patients who are at high risk for having a fracture or who have very low bone density. For people at low risk, fracture protection from osteoporosis medication is not well proven.
Rare harms can occur with long-term use of some osteoporosis drugs. Estimates are that for each year of use, about 1 of every 1,000 patients who take osteoporosis drugs has a harmful side effect. The risk of harm appears to increase the longer a patient stays on the drug, particularly after 4 to 5 years.
This risk of 1 in 1,000 is a 0.001% chance and would be similar to reaching into a bag of 1,000 balls—999 red balls and 1 blue ball—and pulling out the one blue ball. For people at high risk of having a fracture, the benefits of treatment are much greater than the harm. Treatment will reduce the risk of a fracture.
The two most publicized side effects are:
- Atypical femur fracture: One of the harmful effects that has been reported is a tendency for some patients to suffer a fracture, right in the middle of the long thighbone — with hardly any injury. Many patients who have had these fractures report a deep, aching pain in the middle of the thigh several weeks to months before that bone breaks. The ache is not joint pain and not related to exertion or physical activity.
- Osteonecrosis of the jaw: The other harmful effect is a condition where the bones that support the teeth break down and don’t heal — the medical term is osteonecrosis of the jaw (ONJ). ONJ usually occurs after dental procedures like implants or extractions and has been linked to high dose bisphosphonates used in patients with cancer. ONJ tends to happen in patients who have poor oral health.