There are several medications that can be used for treating osteoporosis, some are oral, others are injectable; some must be taken daily, some weekly or monthly, others every 6 or 12 months. Your Bone Health Program physician or provider will recommend the most appropriate option for you, based on the severity of the condition, your personal history and needs, your age and many other factors that must be considered for best effectiveness and safety.
It is important to keep in mind that the goal of any osteoporosis treatment is to reduce fracture risk, more than increasing bone density, although the latter is always desirable. As important, all the pharmacological options currently available have been thoroughly tested in large, randomized clinical trials involving tens of thousands or women and men across the globe, and have been approved by the US Food and Drug Administration (FDA), which has very stringent criteria for effectiveness and safety of any drug that comes to market. All these medications have been shown to reduce the risk of fracture by 30 to 80%; so they are all very effective.
All these medications, through different mechanisms, reduce the process of bone breakdown (resorption) by acting on bone resorbing cells (osteoclasts). This results in stabilization or even increase in bone density, conserved bone quality and decreased fracture risk. It is the largest group and comprises agents of different classes.
Oral bisphosphonates, such as alendronate (Fosamax®), risedronate (Actonel, Atelvia®), and ibandronate (Boniva®), are the most widely used. They are taken weekly or monthly, on an empty stomach, first thing in the morning (to ensure good absorption and avoid esophageal irritation). Treatments typically are for up to 5-6 years; and can be repeated multiple times. These medications are very safe, but if not taken properly they can cause heartburn (esophageal irritation); however, they do not cause gastroesophageal reflux disease (GERD).
Raloxifene (Evista®) is a “design estrogen” that mimics the beneficial effect of estrogen hormones on bone without estrogen’s unwanted effects on the breast and uterus. In fact, raloxifene is sometimes used in the treatment of breast cancer. A similar agent is bazedoxifene, which is available in association with estrogen (Duavee®). Unlike estrogen, these medications can cause menopausal symptoms (hot flashes); like estrogen, they can increase the risk of deep vein thrombosis in people at high risk of such events (personal history, bedridden subjects, long-term travel).
Zoledronic Acid (Reclast®) belongs to the bisphosphonate class, but it is given by i.v. infusion once a year. It is remarkable that the effect of a drug can last so long as one year, but this is because zoledronic acid binds to the bone tissue and it is released very slowly over several months. The most common side effect is flu-like symptoms (muscle or join aches, fever) that typically resolve in a few hours, can be prevented by antihistamine medications, and occur only after the first infusion.
Denosumab (Prolia®) is a human antibody that recognizes and removes a bone protein (RANKL), resulting in reduced number and function of cells that break down bone (osteoclasts). It is given by i.m. injection every 6 months. The most common side effect is minor discomfort at the injection site and low serum calcium. It is very important to keep the 6-month schedule, since missing a dose for 3 months or longer may increase the risk of bone loss and fractures.
These agents directly stimulate bone building cells (osteoblasts) to produce more bone. This results in substantial increases in bone density, improved bone quality and reduced risk of fractures. They are typically used in more severe cases, when stopping bone breakdown may not be enough to reverse the bone deterioration.
Teriparatide (Forteo®; Teriparatide Injections) is a small fragment of the natural hormone, parathyroid hormone (PTH). Abaloparatide (Tymlos®) is also a small molecule that resembles the natural hormone, parathyroid hormone-related peptide. They have a very similar mechanisms of action and act directly on bone forming cells. They come as pre-filled pen-like devices for self-administered subcutaneous, daily injections. They can only be used for up to 2 years because longer clinical trials have never been performed. The most common side effect is leg cramps, which can be minimized by taking the injection before going to sleep. Romosozumab (Evenity®) is a human antibody that recognizes and removes a bone protein (sclerostin) that slows down bone formation, thus freeing the bone building cells (osteoblasts) to produce more bone. It also slows down the process of bone breakdown. All this results in rapid increase in bone density. It is given as two i.m. injections every month. The most common side effect is arthralgia and minor discomfort at the injection site. Evenity should not be used in subjects who have had a heart attack or stroke.