Quinine and cramp: uncertainty efficacy, major risks

(1) Simple muscle cramp is a mild condition. It is defined as painful involuntary muscle contraction that occurs at rest and resolves spontaneously. (2) Passive stretching of the affected muscle relieves cramp. (3) The clinical file on quinine in simple cramp is inadequate, being based on small trials with conflicting results. (4) Two meta-analysis of comparative cross-over trials suggest that the benefit of quinine is negligible in this setting (less than one cramp avoided per week of treatment). (5) Severe and even fatal adverse effects have been reported, especially haematological complications such as thrombocytopenia, haemolytic anaemia, pancytopenia, and disseminated intravascular coagulation. (6) Dose-dependent sensory manifestations of cinchonism are far from rare (especially tinnitus). (7) The risk-benefit ratio of quinine in cramp is too unfavourable to justify its use.