Bisphosphonates are drugs used for osteoporosis by preserving the bone and preventing its further breakdown. It includes such drugs as alendronate, risedronate, pamidronate, ibandronate, and zoledronate. There are many drugs used in the treatment of osteoporosis but none are as important as a group of drugs known as bisphosphonates (bis-fos-fo-nate-s). There are three generations of bisphosphonates and the newest is about 10,000 more effective that its first generation counterparts. Without these bone saving drugs, the medical treatment for osteoporosis would not be as effective as it is today. Yet many osteoporosis sufferers avoid the drug, especially in the early stages of the disease, due to at times an unrealistic fear of the side effects of these drugs.
Bone is constantly undergoing remodeling throughout life. New bone is laid down by a bone cell known as an osteoblast. At the same time old bone is resorbed by the osteoclasts. This is normally kept in balance. In osteoporosis, the bone becomes weak, brittle and prone to fractures. With regards to the bone cells, it can arise with increased osteoclast activity (more bone taken up than normal) and/or decreased osteoblast activity (less new bone laid down).
Bisphosphonates are able to help in osteoporosis by killing off osteoclasts. This is done by the substance being laid down in the bone, then being absorbed into the osteoclast when it consumes bone and then destroying the osteoclast. The structure of bisphosphonates and its presence in the bone ensures that it can specifically target the osteoclasts. By decreasing osteoclast activity, osteoporosis can to be reversed to some degree or at the very least the progression of the disease can be slowed.
There are other ways in which bisphosphonates help with bone strength but it ultimately focuses on decreasing bone resorption.
These drugs are not without side effects but this should not detract from its importance in treating osteoporosis. Dietary change and exercise along with other conservative measures can be helpful in osteoporosis but bisphosphonates should still be used if prescribed. The drug should not be discontinued without a doctor’s supervision.
Bisphosphonates can cause upper gastrointestinal disturbances which are among the more common side effects. This area includes the esophagus (food pipe), stomach and first part of the small intestine (duodenum). It can cause :
Osteoporosis patients using bisphosphonates and experiencing severe upper gut upset may need to take another medication known as proton pump inhibitors (PPIs). This reduces stomach acid production. The medication schedule may also need to be changed but this should only be done after consulting with a doctor.
Other side effects includes fever, muscle pain, kidney problems and weakening of the bone through another disease known as osteomalacia. Due to its impact on the upper gut and kidney, bisphosphonates should not be used by any person with peptic ulcers or chronic kidney disease. Despite its effectiveness, osteoporosis treatment may also require the use of other drugs. None, however, target the bone cell activity directly and to the degree as is seen with bisphosphonate use.