Failure of magnesium sulphate to prevent suxamethonium induced muscle pains.

In fit unpremedicated patients undergoing minor operations and who were ambulant on the afternoon of the operations, pretreatment with magnesium sulphate given intravenously did not reduce the incidence of suxamethonium induced myalgia below that in a similar series who received no prophylactic therapy. The injection of magnesium in conscious patients is followed by unpleasant side effects.