Very recently the FDA decided that they were basically rescinding their previous authorization for prescribing quinine sulfate for the treatment of night cramps. AFAIK it is still being produced and dispensed, as we in the pharmacy haven’t been told to remove it from our shelves.
However, another brand name medication has recently arisen that’s targeted for patients with leg cramps. The ingredient in this brand-only medication? Quinine sulfate. So what gives? The FDA decides that it’s not okay to prescribe quinine sulfate for leg cramps, considering it is a dirt-cheap generic in all strengths, but approves a brand name of quinine sulfate for the treatment of leg cramps?
It was a good move to pull the drug for cramps. I am not aware that the FDA has approved any other quinine products for leg cramps. In fact, the only product they have approved that contains quinine sulfate is used to treat malaria that is resistant to other drugs, and the FDA labelling specifically states it is not to be used for leg cramps. It’s also about 50 times more expensive than the old quinine sulfate tabs were.
As a physician who’s looked into the matter, I agree with them. Quinine sulfate is a dangerous drug, there is no good evidence that it actually works better than placebo for leg cramps, and there are other meds out there that are safer, and have been shown to be effective for leg cramps.
I know that Qualaquin is still on the market, but I distinctly remember throwing away (of course :smack: ) a mailed ad about a new brand name medication that had quinine in it as a therapy for leg cramps. If I could just go back a couple days and dig through my blue trash bags of PHI…
I could be misinformed, however. Thanks for clearing that up. Would you mind elaborating on why quinine is such a dangerous drug?
With the phasing out of it I know there have been patients with good success with clonazepam, but besides that what else is effective for leg cramps?
-foxy
ETA: I haven’t seen many patients who complained of leg cramps who were taking potassium for their furosemide. Is there a correlation there?
I thought that once a drug was approved for prescription use, a doctor could legally prescribe it for any other purpose (so-called “off-label” use). The PDF linked to above mentions that Qualaquin was approved, so couldn’t a doctor prescribe that for leg cramps if he likes?
A lot of medications are prescribed for off-label use, that’s how Viagra came about (originally researched as a blood pressure medication) or Topamax (now commonly used for migraines, originally prescribed for seizures). The FDA has said that they are not approving quinine for leg cramps, so there’s a difference between saying that a drug has an off-label use and strictly forbidding it from being prescribed for a certain off-label use.
Thanks, Derleth, for the excerpt and Qadgop for the link. So what I’m wondering now is, does quinine have an actual therapeutic value for nocturnal leg cramps, and is there a possibility of it being resubmitted with a New Drug Application? Or is the FDA just concerned with the fact that it hasn’t been demonstrated that the harms/benefit ratio of the drug was not widely aware to prescribers?
How many more people you suppose took aspirin? Risk isn’t just about raw numbers, but likelihood of an adverse reaction. Also important is the efficacy and the seriousness of the condition it treats. If a drug causes a lot of adverse events, but it cures cancer 100% of the time, it will likely remain approved. If it causes a lot of adverse events and it is supposed to cure leg cramps and it doesn’t even do that very well (and not as well as much safer alternatives), it will get pulled.
Again from the PDF (which I can just copy from, as if it were a real text file):
So the drug is not extremely effective against craps, and certainly not effective enough to keep using for that purpose in the face of the risks involved. Personally, I used it for my leg cramps and I never got toxicity. I also have no real evidence it helped. (I HATE it when people rely on anecdotal evidence when something really matters, especially when there is real evidence to hand.)
I don’t think it is used as an anti-diarretic, Derleth.
However, Quinine water aka Tonic does contain Quinine and apparently in a low enough dose to be safe.
"Quinine is a flavour component of tonic water, bitter lemon, and vermouth. According to tradition, the bitter taste of anti-malarial quinine tonic led British colonials in India to mix it with gin, thus creating the gin and tonic cocktail, which is still popular today in both India and Great Britain, and in other former British colonies.
In the United States, the Food and Drug Administration limits tonic water quinine to 83 ppm, which is one-half to one-quarter the concentration used in therapeutic tonic."
" of mild cinchonism (which may occur from standard therapeutic doses of quinine) include flushed and sweaty skin, ringing of the ears (tinnitus), blurred vision, impaired hearing, confusion, reversible high-frequency hearing loss, headache, abdominal pain, rashes, lichenoid photosensitivity [1], vertigo, dizziness, dysphoria (feeling uneasy), nausea and vomiting, and diarrhea.
Large doses of quinine may lead to severe symptoms of cinchonism: skin rashes, deafness, somnolence, diminished visual acuity or blindness, anaphylactic shock, and disturbances in cardiac rhythm or conduction, death from cardiotoxicity. Quinine overdose can also result in a rare form of hypersensitivity reaction termed blackwater fever that results in massive hemolysis, hemoglobinemia, hemoglobinuria, and renal failure.
Patients treated with quinine may also suffer from hypoglycemia (especially if administered intravenously) and hypotension (low blood pressure). In very high doses (higher than those used to treat malaria) during the first trimester of pregnancy quinine may act as an abortifacient, or cause birth defects, especially deafness.
Most symptoms of cinchonism (except in severe cases) are reversible and disappear once quinine is withdrawn."
