I heard there is a medication given once a year called Reclast (zoledronic acid). Is it like other bisphosphonates?
Reclast (zoledronic acid) is another bisphosphonate available for intravenous (IV) administration. Like Boniva, it is used to treat postmenopausal osteoporosis. Unlike Boniva, IV administration is done only once every 12 months (see Table 11). Because it is only given intravenously, Reclast does not include following the complex regimen required for taking oral bisphosphonates. IV administration does require a visit to your clinician's office. To protect your kidneys, you must be well hydrated prior to receiving your yearly dose of Reclast, which means drinking lots of water and sometimes getting extra fluids through the IV before receiving the medication. The 5 mg of Reclast comes in an IV bag of 100 milliliters of fluid (a little over 3 ounces), and administration takes about 15 to 20 minutes.
Reclast is very effective in reducing vertebral fractures. Clinical studies showed that it reduced new vertebral fractures by about 75% when compared to placebo. It also reduced new fractures in the hips and at other sites by 25% to 35%.
Some patients are reluctant to try Reclast because they are concerned about the needle insertion needed for IV administration. Usually the nurses giving Reclast are very skilled in doing IV medication administration and it is over before you know it. For many people, the once-a-year administration schedule overrides any concerns about the need for IV administration because it does not require daily, weekly, monthly, or every-3-months administration that can sometimes be hard to follow or remember.
Table 11 Reclast (zoledronic acid)
Reclast was well tolerated in a study done with patients who had recently experienced a low-trauma hip fracture. Patients receiving Reclast were less likely to have adverse events or die than those receiving placebo. Patients receiving Reclast also had significantly fewer fractures. A study evaluating more than 7700 postmenopausal women with osteoporosis also showed that the medication was very well tolerated and that fractures were reduced.
Reclast is also FDA-approved for treatment of Paget's disease (see Question 60). Another form of zoledronic acid, known as Zometa, is used in higher doses with more frequent administration for bone cancers, multiple myeloma, and high blood calcium levels associated with some types of cancer. Recent research suggests that Zometa may also be helpful in reducing breast cancer recurrences and metastases. Reclast is not used in combination with other osteoporosis medications.
Didronel (etidronate) is usually prescribed for Paget's disease. Is it ever prescribed for osteoporosis?
Didronel (etidronate) is another bisphosphonate. It is FDA-approved for Paget's disease, high calcium levels related to cancer, and rare bone conditions related to hip replacement surgery, but not for osteoporosis. Outside of the United States, Didronel is used for osteoporosis. It works a little differently from other bisphosphonates in that it kills off the osteoclasts (the cells that break down bone). Nonetheless, Didronel has been very effective in reducing osteoporosis-related fractures, particularly spinal ones, and safety has been established for 7 years or more use in postmenopausal women. Additionally, like other bisphosphonates, some protective effects of Didronel on bone density have been shown to persist even after stopping the medication. Didronel is not FDA-approved for treatment or prevention of osteoporosis in the United States.
Although Paget's disease is also a bone disease, it is totally unrelated to osteoporosis. One person can have both conditions. Paget's disease causes large, deformed bones because of an excessive breakdown and formation of bone. The most common presenting symptom is bone pain located where the bone is closest to a joint. Paget's disease can often be mistaken for arthritis because it is usually diagnosed in people who are over 40 years of age. However, x-rays of bones in individuals with Paget's disease show a characteristic pattern and fractures occur frequently. Blood levels of alkaline phosphatase are usually elevated in people with Paget's disease. If the skull bone is affected, hearing loss can result.
The treatment of choice for Paget's is a bisphosphonate. Bisphosphonates Actonel, Fosamax, Reclast, and Didronel are FDA-approved for the treatment of Paget's. Unlike the longer dosing regimens of other bisphosphonates, Didronel is generally prescribed for only 2 weeks to 3 months at a time depending on the dosage, with a rest period off the medication lasting at least 3 months. This regimen is usually repeated for about 2 years. Didronel is taken on an empty stomach without eating or drinking for 2 hours after taking it. Didronel should still be prescribed with caution in those with upper intestinal disorders. The most common side effects include nausea, diarrhea, and flatulence. Medications that cause stomach upset, such as NSAIDs like ibuprofen, naproxen, or aspirin, can increase the risk for ulcer or heartburn. Table 12 has information on Didronel.
Table 12 Didronel (etidronate)
-  Causes large, deformed bones due to the excessive breakdown and formation of bone. Although totally unrelated to osteoporosis, it can occur with osteoporosis in the same bones.