Bisphosphonates are a class of drugs used in the treatment of osteoporosis, and other bone conditions that result in a loss of bone mass. Phosphate is, along with calcium, a necessary component in the formation of healthy bones – hence where the class got their name. In conditions such as osteoporosis, these mineral deposits will be deficient and, consequently, it’s necessary to replenish these minerals. In bone, there are two main competing types of cell – osteoblasts and osteoclasts. Osteoblasts function to form the bone while osteoclasts serve to destroy bone. Bisphosphonates fit into this equation as they are responsible for blocking the function of osteoclasts – meaning the osteoblasts can make more healthy bone. Bisphosphonates have proven very effective in this role.
Drugs that are considered to be a part of the bisphosphonates drug class include:
Bisphosphonates are not only effective in the treatment of osteoporosis but have also proven effective in other conditions where the risk of bone fractures remains high. For this reason, bisphosphonates are also used in the treatment of Paget’s disease, multiple myeloma, osteogenesis imperfecta.
Many cancer patients also benefit from the use of bisphosphonates. Many chemotherapeutic drugs have the potential to reduce bone mass significantly and increase bone pain, as well as increasing the risk of bone fractures. The administration of bisphosphonates has the effect of ameliorating the risk of these symptoms occurring in afflicted patients.
In addition, bisphosphonates have found use in postmenopausal women. In many postmenopausal women, the likelihood of bone fractures is high, not least because of the hormonal consequences of the menopause.
Bisphosphonates Side Effects
One of the principal challenges with bisphosphonate drugs is their inclination to irritate the esophagus and stomach. This can become particularly problematic as the effective dose may be disrupted and not absorbed at the correct time. This is why patients are advised to remain upright for at least thirty minutes after taking the drug with a large glass of water. This prevents, as much as possible, the interaction of the drug with the lining of the esophagus and stomach.
In patients with cancer, the bisphosphonate drugs have been linked with a condition known as BRONJ – bisphosphonate-associated osteonecrosis of the jaw. If a cancer patient were to take a course of bisphosphonate drugs, they would be at risk of forming this condition if they went to the dentist. The lack of wound healing may, after all, result in infection. Common side effects include:
- Flu-like symptoms
- Irritation to the esophagus
- Changes in bowel movements
- Feeling of sickness
- Low calcium levels in the blood
- Damage to jaw bone
- Damage to kidneys
Patients taking bisphosphonates need to consider the foods and drugs they consume on a daily basis. Food and drugs that contain the minerals calcium, magnesium, and aluminium, should be avoided when taking each bisphosphonate drug. This is because these minerals interact and render obsolete the function of the drug. It’s advised that such drugs and foods should only be consumed at least 30-60 minutes after taking the oral drug.
Interactions may also occur with NSAID drugs such as aspirin and ibuprofen. NSAIDs carry a risk of gastric ulceration and this risk is augmented when taken with bisphosphonate drugs. It’s, therefore, recommended that patients do not take these drugs at the same time but, instead, space their use out as much as reasonably possible.