Introduction:
Quinine, also known as Cinchona, Cinchona Bark, Fever Tree, Jesuit’s Bark, Peruvian Bark, Quina-Quina, Red Cinchonais an agent produced from the bark of the South American Cinchona tree. It is also produced synthetically. Quinine has been traditonally used for malaria treatment but new, more effective agents are available.
Quinine use and the FDA:
Quinine has been prescibed by physicians for leg cramps off-label without any strong evidence of effectiveness (1). The FDA has warned for many years that harm outweighs benefit of this agent for this condition (1). Quinine is also present in small amounts of tonic water to produce a bitter taste. The dose of quinine is quite small in tonic water, and one would need to consume over 6 liters of tonic water to obtain one therapeutic dose of quinine. Quinine is present in cinchona bark which is available over the counter in herbal supplement stores as a variety of different names. Cinchona bark has an unknown quinine content, and is not standardized or regulated by the FDA.
Quinine adverse effects:
Quinine or cinchona bark toxicity includes nausea, vomiting, confusion, blurred vision, dizziness, hearing loss, headache, arrythmia, hemolysis, rash, and renal failure.
Quinine and risk of bleeding:
Quinine can increase bleeding risk by potentiating warfarin (Coumadin) and patients need to stop taking these supplements with blood thinning agents (2).
Assessment and Plan: Quinine and Cinchona Bark
- Quinine has been prescibed by physicians for leg cramps off-label without any strong evidence of effectiveness, and the FDA has warned for many years that harm outweighs benefit of this agent for this condition (1).
- Quinine is present in cinchona bark available as an herbal supplement which has an unknown quinine content, and is not standardized or regulated by the FDA.
- Quinine or cinchona bark toxicity includes nausea, vomiting, confusion, blurred vision, dizziness, hearing loss, headache, arrythmia, hemolysis, rash, and renal failure.
- Quinine can increase bleeding risk by potentiating warfarin (Coumadin) and patients need to stop taking these supplements with blood thinning agents (2).
References:
1.FDA Orders Unapproved Quinine Drugs from the Market and Cautions Consumers About “Off-Label” Use of Quinine to Treat Leg Cramps. U.S. Food and Drug Administration, Silver Spring, MD 20993, Ph. 1-888-INFO-FDA (1-888-463-6332). http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108799.htm
2.Argento, A., Tiraferri, E., and Marzaloni, M. Oral anticoagulants and medicinal plants. An emerging interaction. Ann.Ital.Med Int 2000;15(2):139-143. http://www.ncbi.nlm.nih.gov/pubmed/10920504