Quinine not routine for treating leg cramps

Quinine should not be routinely prescribed to treat leg cramps, advises the MHRA in its latest newsletter (Drug Safety Update 2010;3:Issue 11).

    Quinine offers only modest efficacy – an average reduction of one episode per week against a baseline of 17 per week – and may be associated with thrombocyto­penia; it is toxic in overdose and may cause loss of vision. The MHRA says quinine should only be prescribed when leg cramps regularly disrupt sleep, initially for a trial period of four weeks followed by three-monthly reviews if effective.