Is it safe to use quinine (quinine) lozenges to treat shin cramps in a patient with thrombocytopenia (low platelet count)?

From the Guidelines

It is not recommended to use quinine lozenges to treat shin cramps in patients with thrombocytopenia. Quinine, even in lozenge form, can potentially worsen thrombocytopenia by triggering immune-mediated platelet destruction, as suggested by the association of quinidine/quinine with thrombocytopenia in the study 1. This medication has been associated with serious hematologic adverse effects, including thrombocytopenia, which could be dangerous in someone who already has a low platelet count.

Key Considerations

• The study 1 highlights the importance of considering medications that may cause thrombocytopenia, including quinidine/quinine, in the evaluation of patients with low platelet counts.
• Given the potential risks, safer alternatives should be considered for patients with thrombocytopenia experiencing muscle cramps, such as:
  • Stretching exercises
  • Proper hydration
  • Electrolyte replacement (particularly magnesium and potassium)
  • Addressing any underlying causes of the cramps
• If medication is necessary, muscle relaxants or calcium channel blockers might be considered under medical supervision.

Patient Guidance

Any patient with thrombocytopenia should consult their hematologist before taking any new medications, including over-the-counter products containing quinine, to avoid potentially dangerous decreases in platelet counts that could increase bleeding risk, as indicated by the consideration of drug-induced thrombocytopenia in the study 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. Quinine-induced thrombocytopenia is an immune-mediated disorder. Severe cases of thrombocytopenia that are fatal or life threatening have been reported, including cases of HUS/TTP.

It is not safe to use quinine lozenges to treat shin cramps in a patient with thrombocytopenia (low platelet count) due to the risk of serious and life-threatening hematologic reactions, including worsening thrombocytopenia and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP) 2, 2.

From the Research

Safety of Quinine Lozenges for Shin Cramps in Thrombocytopenia

• The use of quinine lozenges to treat shin cramps in patients with thrombocytopenia (low platelet count) is a concern due to the potential risk of exacerbating thrombocytopenia 3, 4, 5.
• Quinine has been reported to cause thrombocytopenia in some cases, with a median time-to-onset of 7 days and clinical severity that may require hospitalization 5.
• Studies have shown that quinine can induce thrombocytopenia through immune-mediated platelet destruction, which can be severe and life-threatening 4, 5.
• The diagnosis of quinine-induced thrombocytopenia can be difficult and requires a detailed history of all medications, including over-the-counter medications and herbal preparations 3, 4.

Efficacy and Safety of Quinine for Muscle Cramps

• Quinine has been shown to be effective in reducing the frequency, intensity, and duration of muscle cramps, including shin cramps, in some studies 6, 7.
• However, the safety of quinine for long-term use is a concern, and it should be used with caution, especially in patients with renal failure or liver disease 6, 7.
• The optimal dose and duration of quinine use for muscle cramps are not well established, and further research is needed to determine its safety and efficacy 6.

Clinical Considerations

• Clinicians should be aware of the potential risk of quinine-induced thrombocytopenia and monitor patients closely for signs of thrombocytopenia, such as bleeding or bruising 3, 4, 5.
• Patients with thrombocytopenia should be cautioned against using quinine lozenges or any other quinine-containing products without consulting their healthcare provider 3, 4, 5.
• Alternative treatments for shin cramps, such as stretching exercises or other medications, should be considered in patients with thrombocytopenia or other contraindications to quinine use 6, 7.