In 2014, the FDA finally acknowledged that CRPS is indeed, a rare condition. This has vast implications for pharmaceutical companies, as this is a game changer when it comes to CRPS research. These companies may now receive attractive tax breaks, and may include fewer subjects in any studies necessary to prove the ethicacy of a drug developed specifically for CRPS. In addition, such companies may market the drug for seven years without threat of competition. This is getting a lot of corporate attention. The first company to launch such research in the USA was Grunenthal, a German- based company, and the trail medication is neridronate, also known as amino-bisphosphate. This study is expected to be completed in 2016.
Significant attention has been focused on this drug since a very small but successful trial was completed in Italy44. The inclusion for this trial was very strict, as no one whose CRPS onset was greater than four months ago was allowed to participate. This study reported a good outcome of up to a year. Surprisingly, the placebo group in this study also reported a marked initial decrease in pain. The USA study trail inclusion will not be as strict, with the exception of patients who suffer from CRPS Type 2, meaning that nerve damage can be detected. Neridronate has been used in Europe for quite some time now. Bisphosphates are a class of drugs that prevent the loss of bone mass, used to treat
osteoporosis and similar diseases. Bone undergoes constant turnover and is kept in balance by specific bone cells called osteoblasts (that create bone) and osteoclasts (that destroy bone). Bisphosphonates inhibit the destruction of bone by encouraging osteoclasts to undergo cell death, thereby slowing bone loss. It does not encourage new bone growth, but simply slows down bone loss.
The side effects of this drug include muscle tremors, muscle and joint pain, inflammation of the eye, fever, cardiac arrhythmia, artrial fibrillation, thyroid problems and jaw necrosis. Since this last side effect is often glossed over, I want to make sure that we address it in detail, so that you understand the gravity of it. Necrosis means dying of the bone that form the jaw and house the teeth. This is not an uncommon side effect at all. This occurs more often when bisphosphates are administered through an IV, rather than orally. One large study found that 20% of IV bisphosphate users will develop necrosis of the jaw. There is no way to prevent this side effect. It is most often triggered by dental work after the drug has been administered, especially any kind of dental surgery. The risk remains high for the lifetime of the patient. Many dentists will not agree to work on a patient who has taken this drug, due to fear of complications. The symptoms of jaw necrosis include bad breath, lock jaw, abscesses, pockets of pus, loosening teeth, numbness in the face, feeling of heaviness in the jaw, and swelling of the gums or face.
Much hope is being focused on the current USA trial. Caution is advised, however, since the safety of taking this drug long term has not been studied, and the known side effects are potentially serious. There is no word yet on possible insurance company coverage of this treatment, nor the cost of this treatment.