Management of Muscle Cramps

Initial Treatment

The American College of Physicians recommends starting with baclofen 10 mg/day, increasing weekly by 10 mg increments up to 30 mg/day, as this is the first-line pharmacological treatment, with a strength of evidence of high quality 1
Apply ice and massage to the cramping muscle, and ensure adequate hydration and correct any documented electrolyte abnormalities, particularly hypokalemia and hypomagnesemia, as recommended by the American Academy of Neurology 1

The American Academy of Neurology recommends starting baclofen at 10 mg/day (or 5 mg three times daily in older adults), and increasing by 10 mg weekly up to a maximum of 30 mg/day, with a strength of evidence of moderate quality 1
Monitor for dizziness, somnolence, gastrointestinal symptoms, muscle weakness, and cognitive impairment, as recommended by the American Geriatrics Society 1
Never discontinue baclofen abruptly after prolonged use—taper slowly to prevent withdrawal symptoms including CNS irritability, as recommended by the American Academy of Neurology 1

The National Kidney Foundation recommends correcting documented deficiencies, not empiric supplementation, with magnesium oxide 12-24 mmol daily (480-960 mg) given at night for true hypomagnesemia, with a strength of evidence of high quality 2
Always correct water and sodium depletion first, as secondary hyperaldosteronism worsens magnesium losses, as recommended by the American Heart Association 2
Avoid magnesium supplementation in renal insufficiency—magnesium is renally excreted and can accumulate to toxic levels, as recommended by the National Kidney Foundation 2

The American Geriatrics Society recommends starting baclofen at lower doses (5 mg three times daily maximum initially) in older adults, and monitoring carefully for muscle weakness, urinary dysfunction, cognitive effects, and sedation, with a strength of evidence of moderate quality 1
The British Journal of Sports Medicine recommends reviewing medications that affect hydration or thermoregulation (dopamine reuptake inhibitors, diuretics) with healthcare providers before training in hot environments, especially for patients with recent gastrointestinal illness or fever, with a strength of evidence of low quality 3

The American College of Sports Medicine recommends maintaining hydration with carbohydrate-electrolyte beverages during prolonged exercise in heat, which can delay (but not prevent) cramp onset, with a strength of evidence of moderate quality 4
Address heavy sodium losses in "salty sweaters" exercising in hot environments, as recommended by the National Athletic Trainers' Association 4

The FDA recommends avoiding quinidine due to toxicity and only modest benefit, as recommended by the American Heart Association 1
The American Academy of Neurology recommends avoiding cyclobenzaprine, as it should not be prescribed with the mistaken belief it directly relieves muscle spasm, with a strength of evidence of low quality 1

The American Association for the Study of Liver Diseases recommends reducing or discontinuing diuretics if cramps are incapacitating in patients with liver disease, and monitoring for hepatic encephalopathy when using baclofen 5
The American College of Sports Medicine suggests that athletes maintain hydration with carbohydrate-electrolyte beverages during prolonged exercise in heat, and address sodium losses in "salty sweaters" exercising in hot environments, aiming for 0.5-0.7 g/L sodium in fluids, increasing to 1.5 g/L if cramping persists 6

The International Marathon and Distance Racing Medical Association recommends including 30-60 g/h of carbohydrates for exercise lasting >1 hour 6