For better or for worse, virtually all prescription drugs must be officially approved by the Food and Drug Administration (FDA), an immense bureaucracy that regulates the vast segment of our economy that the words “food” and “drugs” imply. (Though, somehow, the FDA can’t seem to get cigarettes off the market.) Before any drug is available for prescription, it must pass muster with a series of clinical trials and meet the approval of several separate committees.
When a drug is approved by the FDA, the approval applies only to specific medical conditions: Drug A is OKd for diabetes, Drug B for migraine, and so forth. Even though it’s not at all illegal to prescribe drugs A or B for other conditions, most physicians, fearing a visit from a malpractice attorney, prescribe according to FDA approval guidelines.
This, of course, presents a problem when a medicine for disease A is found to be helpful for disease B. The term for this is off-label prescribing. When, for example, the blood pressure meds called beta-blockers were found to be excellent at preventing migraines, it took a decade of off-label prescribing before enough clinical trials were conducted to add migraine prevention to the FDA approved-use list for beta blockers.
If a new use is found for an older drug, the pharmaceutical companies are forbidden to breathe a word about it to the public or to physicians until the required clinical trials are completed. When physicians reported the epilepsy drug Neurontin helped patients with chronic pain, migraines, and bipolar disorder, drug reps from Neurontin’s manufacturer Pfizer Labs began spreading the word, with the result that the company was fined $430 million for illegal marketing. These days, a drug rep would sooner cut off her tongue than discuss an off-label use for the med she’s touting.
All this relates to the off-label prescribing of a drug you’ve likely never heard of and probably won’t ever need: naltrexone. This is a medication FDA-approved only for serious addiction to opioid painkillers like Vicodin or OxyContin. It works by blocking the brain’s receptor sites for opioids, so if you take naltrexone and Vicodin together, the Vicodin doesn’t do anything—its effect is completely blocked.
Several years ago, a doctor discovered that people using naltrexone who also had Crohn’s disease reported their intestinal symptoms suddenly improved. He managed to get enough people interested until researchers from Hershey Medical Center at Penn State conducted clinical trials. 15 of 17 patients with Crohn’s reported feeling better and their disease stabilized. It was postulated that somehow the naltrexone altered the immune system for the better. Remarkably, a very low naltrexone dose (4.5 mg) was more effective than the 50-mg dose for opioid addiction. Also, because of this low dose side effects were virtually non-existent.
Thinking then of other autoimmune disorders, researchers began using low-dose naltrexone (LDN) for multiple sclerosis. Again, preliminary studies are very encouraging.
Then, naltrexone went generic. This meant the price was quite low and for precisely that reason no drug company would foot the bill for the high costs of obtaining coveted FDA approval. So there it sits, languishing. The term for this? Naltrexone is an orphan drug. One small company recently ran trials combining LDN with the antidepressant Wellbutrin for weight loss and saw very positive results. But the FDA wouldn’t give its approval until the company came up with a larger study that involved more patients. Unfortunately, the company may have run out of money for these costly clinical trials.
What’s interesting is how the medical profession responds to LDN. I have yet to meet a single gastroenterologist who has even heard of using LDN for Crohn’s disease. When I’ve asked if they’d prescribe it, the answer is the standard “Probably not. Let’s wait for FDA approval.” Which will, of course, probably never occur.
Because of its large internet presence, the multiple sclerosis community has plenty of articles on LDN and I imagine patients must be badgering their neurologists a-plenty. MS patients tell me their doctors will write an LDN prescription if asked. But interestingly, it’s never offered to them.
Among doctors whose specialty is weight loss (bariatricians), some are writing LDN prescriptions with Wellbutrin in a proportion similar to that recently blocked by the FDA. To these doctors, the results and the safety profile were satisfactory.
You can read more about the use of LDN for MS here and watch a news report on it here.
David Edelberg, MD