An approach to muscle cramps for the pharmacist : evidence-based pharmacy practice

A muscle cramp is an involuntary contraction (tightening) or spasm of a muscle. This contraction is often painful and can be caused by movement. The cramping causes the muscle to feel hard, and the muscle often seems to bulge. Cramps can affect one muscle or a group of muscles. Although muscle cramps are associated with a number of medical conditions, for example, dehydration, neuropathies, hypomagnesaemia, hypocalcaemia, hypothyroidism, renal disease and pregnancy, they frequently occur without an identifiable underlying cause. They are then referred to as idiopathic muscle cramps, a common medical complaint that is more frequent in the elderly. Although any muscle group can be affected, usually they occur at night in the lower limbs. Treatment options include quinine and its derivatives, but these medicines are associated with significant, primarily haematological, adverse events. Therefore, they should not be used routinely in the treatment of muscle cramps. Small studies have suggested that gabapentin, diltiazem and vitamin B complex are effective in treating muscle cramps. However, the results of these studies should be confirmed by larger trials. Stretching and massage are common non-pharmacological treatments that are used. There is limited evidence of their effectiveness. More research is needed on the safety and effectiveness of treatments for muscle cramps.