Frequently Asked Questions for Pharmacists on Quinine Sulfate
Q: May I dispense quinine sulfate for leg cramps?
A: Federal law expressly prohibits the sale of over-the-counter quinine sulfate products. 21 C.F.R. Sections 310.546 & 310.547.
Effective February 13, 2007, the Food & Drug Administration (“FDA”) ordered all manufacturers of prescription quinine sulfate products not approved for marketing by FDA to cease manufacturing. FDA has approved one quinine sulfate product, Mutual Pharmaceutical Company’s Qualaquin, for the treatment of malaria only. At this writing, Qualaquin remains the only FDA-approved quinine sulfate product on the market.
As noted FDA approved Qualaquin for the treatment of malaria only. Indeed, FDA-approved labeling for Qualaquin specifically states that “Quinine sulfate oral capsules are not approved for the treatment or prevention of nocturnal leg cramps.” The labeling further states in the warning section:
Quinine sulfate may cause unpredictable serious and life-threatening hypersensitivity reactions, QT prolongation, serious cardiac arrythmias including torsades de pointes, and other serious adverse events requiring medical intervention and hospitalization. Fatalities have been reported. The risk associated with the use of quinine sulfate in the absence of evidence of its effectiveness for treatment or prevention of nocturnal leg cramps, outweighs any potential benefit in treating and/or preventing this benign, self-limiting condition.
In short, FDA-approved labeling affirmatively warns that quinine sulfate is unsafe for the treatment of leg cramps.
The Board is aware that numerous physicians continue to prescribe quinine sulfate for leg cramps. In light of the approved labeling's warnings about the lack of safety, such prescribing seems at best highly risky. There is nothing, however, in the law that absolutely prohibits a prescriber from writing for Qualaquin as an “off-label” use for leg cramps.
Pharmacists presented with such a prescription have a choice to make as to whether to fill such a prescription. Under Rule .1801(a), “a pharmacist or device and medical equipment dispenser may refuse to fill or refill a prescription order, if, in his professional judgment, it would be harmful to the recipient, is not in the recipient's best interest or if there is a question as to its validity.” In light of the labeled warnings with regard to treatment of leg cramps with quinine sulfate, a pharmacist would certainly be justified in refusing to fill the prescription. A pharmacist who chooses to fill the prescription notwithstanding the labeled warnings should be aware of the possibility of professional or civil liability should a patient be harmed as a result of using quinine sulfate for leg cramps.
More information concerning quinine sulfate is available at this Q&A monograph issued by FDA.