From the Guidelines
Quinine lozenges are not recommended for treating shin cramps due to insufficient evidence and potential serious side effects. The provided evidence does not support the use of quinine lozenges for shin cramps, and the FDA has warned against using quinine for leg cramps due to risks including cardiac arrhythmias, thrombocytopenia, and severe allergic reactions 1. For shin cramps, better approaches include:
- Proper hydration
- Stretching before and after physical activity
- Ensuring adequate intake of electrolytes (particularly potassium, magnesium, and calcium)
- Gentle massage of the affected area during a cramp If shin cramps are frequent or severe, it's advisable to consult a healthcare provider to rule out underlying conditions like peripheral artery disease or electrolyte imbalances. The mechanism of muscle cramps involves involuntary muscle contractions, and while quinine was historically used to treat them by affecting muscle membrane excitability, its risks outweigh potential benefits for this non-life-threatening condition. Alternative treatments for muscle cramps, such as baclofen, albumin, orphenadrine, and methocarbamol, have been proposed, but quinine lozenges are not a recommended option 1.
From the FDA Drug Label
Quinine sulfate capsules may cause unpredictable serious and life-threatening hematologic reactions including thrombocytopenia and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP) in addition to hypersensitivity reactions, QT prolongation, serious cardiac arrhythmias including torsades de pointes, and other serious adverse events requiring medical intervention and hospitalization. The risk associated with the use of quinine sulfate capsules 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
The FDA drug label does not support the effectiveness of quinine lozenges for treating shin cramps. Key points:
- Quinine sulfate capsules are not approved for the treatment of nocturnal leg cramps.
- The risk of serious side effects outweighs any potential benefit for this condition.
- There is no mention of quinine lozenges in the provided drug labels, only quinine sulfate capsules. 2
From the Research
Effectiveness of Quinine Lozenges for Shin Cramps
- The effectiveness of quinine for treating leg cramps, including shin cramps, has been studied in several trials 3, 4, 5, 6.
- A study published in the Journal of Clinical Pharmacology found that quinine sulfate can be an effective therapy for idiopathic leg cramps, reducing the frequency and severity of cramps compared to placebo or vitamin E 3.
- However, another study published in The Consultant Pharmacist noted that the efficacy trials for quinine in leg cramps have numerous design flaws, resulting in poor quality data and both positive and negative findings 4.
- A randomized controlled trial published in The British Journal of General Practice found that calf-stretching exercises are not effective in reducing the frequency or severity of night cramps, and advising patients to stop quinine treatment temporarily may result in no major problems and allow a significant number to stop medication 5.
- A meta-analysis published in the Journal of General Internal Medicine found that quinine is efficacious in the prevention of nocturnal leg cramps, but its benefit may not be as large as reported from the pooling of published studies alone, and nonpharmacologic therapy is recommended as the best first-line treatment 6.
Safety of Quinine Lozenges
- Quinine has a well-known toxicity profile, involving the hematologic, renal, neurologic, cardiac, and endocrine systems 4.
- A case report published in The Journal of the Oklahoma State Medical Association described a patient who developed occult quinine-induced thrombocytopenia, highlighting the importance of considering drug-induced thrombocytopenia in patients taking quinine for night leg cramps 7.
- The meta-analysis published in the Journal of General Internal Medicine found that the use of quinine was associated with an increased incidence of side effects, particularly tinnitus 6.
Alternatives to Quinine Lozenges
- Several alternatives to quinine have been suggested, including verapamil, gabapentin, carisoprodol, and orphenadrine for the general population, and vitamin E for the dialysis population 4.
- Nonpharmacologic therapy, such as regular passive stretching of the affected muscle, is recommended as the best first-line treatment for nocturnal leg cramps 6.