My clinician wants me to give myself injections of something called Forteo® (teriparatide), which I understand to be parathyroid hormone. Should I take it? How often would I receive an injection?
Forteo (teriparatide) is the only currently FDA-approved anabolic agent used in the treatment of osteoporosis. It actually builds bone, in contrast to antiresorptive agents, which interfere with bone resorption by slowing bone breakdown. Forteo builds new bone by increasing the number of osteoblasts (cells that build bone). And it does that in as little as 3 months of daily treatments.
Forteo is a synthetic form of parathyroid hormone, a naturally occurring hormone critical to bone development (see Question 8). Forteo is approved for treating postmenopausal osteoporosis in women who are at high risk for fracture and for increasing bone mass in men with primary (osteoporosis related to aging) or hypogonadal osteoporosis (osteoporosis caused by hypogonadism, which results from inadequate function of the testes and low testosterone levels) who are at high risk for fracture. Forteo is also approved for the treatment of steroid-induced osteoporosis in women and men at high risk for fracture. Those at high risk for fractures include men and women who have a history of osteoporotic fracture, who have multiple risk factors for fracture, for whom other therapies have not worked,
Table 13 Evista (raloxifene)
or who are intolerant of other osteoporosis therapies. Clinical trials showed that Forteo increased bone density in 94% to 96% of patients and decreased the risk of spinal fractures by 65% and other fractures by 53% in women.
But Forteo has some drawbacks. The FDA has required a "black-box warning" on the Forteo labeling to indicate concern that Forteo may cause osteosarcoma, a rare form of bone cancer. Although no humans developed bone cancer during clinical trials, laboratory rats did develop the disease after receiving Forteo in dosages that were 3 to 60 times higher than those used in humans. The manufacturer, Eli Lilly and Company, is funding a 10-year study to determine if Forteo does cause bone cancer in humans. Using Forteo for longer than 2 years is currently not recommended.
Forteo is taken by self-injection each day from a pre-filled syringe-type "pen" containing about 1 month's worth of medication. After 28 days, the pen is discarded even if there are remaining doses. Each pen contains only 3 milliliters of fluid (a little over 2 teaspoon) and 750 micrograms of the synthetic parathyroid hormone. Although larger doses can be prescribed, the recommended daily dosage is about 20 micrograms. You must store your pen in the refrigerator. If it becomes cloudy or contains particles, do not use it. The contents of the pen should be clear and colorless. Although some people are squeamish about needles, the needle used in the pen is very, very small.
When you are prescribed Forteo, Lilly and Co. provides you with a starter kit that contains an instructional video.
Occasionally patients develop redness and swelling at the injection site, which is in the fat under the skin of either the thigh or the abdomen. If redness spreads, you should report this to your clinician. The most common side effects are nausea, dizziness, and leg cramps, although other side effects such as low blood pressure, weakness, joint pain, fainting, and chest pain can occur.
Forteo is more expensive than any of the antiresorptive therapies. But based on your individual case, you may benefit more from Forteo. If you and your clinician decide that you need to take it, be sure to check with your insurance carrier. The manufacturers of Forteo have a customer service center, and they may be able to assist you in getting the medication covered. Without insurance, Forteo can cost about $650 to $850 per month. Lilly has a patient assistance program called Lilly Cares®. Patients who cannot afford their medication can apply for assistance online or by submitting a form via mail. In some instances, patients can get their medications for no charge.
A clinical trial is under way to evaluate Forteo as an effective treatment option in women who have used either Fosamax or Actonel without success. In a study of women who had taken either Fosamax or Evista for almost 3 years, the women who had been on Evista and switched to Forteo built more bone mineral density, and more quickly, than the women who were switched from Fosamax to Forteo. Evista followed by Forteo was more effective than Fosamax followed by Forteo. Table 14 contains further information about Forteo.
The two prior medications I took for osteoporosis had not helped my bones. In fact, a pair of bone density tests in the
Table 14 Forteo (teriparatide)
same month gave nearly identical results: I am 60 but I had the bones of an 85-year-old!
I was referred to an endocrinologist who ordered blood tests to check my vitamin D levels, which were fine. The recommendation: Forteo, an injectable medication that speeds up the renewal of bone. According to the insert with the Forteo syringe, there are two sets of cells in bone: set #1 breaks down old bone, and set #2 builds it back up again. Ideally, these two sets work in synch; in my case, the second set was "slacking"!
There is a recommended treatment span of 2 years. As there is a black-box warning of bone cancer with this medication, I am looking for any sign of improvement after the first year of treatment, which will (hopefully) be confirmed with a bone density test. The doctor feels that Forteo will certainly prevent further deterioration and, "if we hit a home run, "the damage may be reversed. Meanwhile, I inject myself daily and look forward to hearing better news this year than last.
-  Given into the muscle or fat tissue or vein using a needle with a syringe attached.