Toxic myopathies

Toxic myopathy symptoms range from myalgia and muscle cramps to severe weakness, bearing similarities to a number of other muscle conditions. Thus, when evaluating patients with muscle symptoms, an iatrogenic muscle problem should always be considered, to be able to distinguish a toxic from any other myopathy early on, preventing further muscle damage and to potentially reverse muscle injury by withdrawal of the toxic agent. Various commonly prescribed medications, as well as illicit drugs, may cause muscle damage. These substances may cause muscle injury through direct myotoxic effects, or indirectly through various mechanisms, such as electrolyte abnormalities and triggering, or disinhibiting the immune system response.