Nocturnal leg cramps are particularly common in the elderly and pregnant women. The condition is characterized by painful cramps in the legs or feet that affect sleep quality. Treatment options are limited, but may have some effect by making lifestyle changes and mild stretching. Pharmacological treatment may be considered for people with frequent, severe leg cramps.
What Are Night Leg Cramps?
Nocturnal leg cramps are the sudden contractions of the muscles in the legs or feet during sleep. This painful tightening of the muscle can take from a few seconds to several minutes. Cramps often cause waking and although benign, the affected muscle is painful after a few hours and the consequences of sleep disturbance can be significant. Severe night cramps are characterized by painful, debilitating attacks that last an average of nine minutes and recur at intervals throughout the night. This can lead to secondary insomnia and impaired daytime functioning. Approximately 20% of people who regularly experience nocturnal cramps have symptoms severe enough to affect their sleep quality or require medical attention.
This is common, with a lifetime prevalence of 50-60% in adults and about 7% in children. Calf cramps are particularly common in women who are pregnant and considered a normal part of pregnancy. For many people, the cause of their cramps is unknown, and however, dehydration, electrolyte and mineral imbalances, muscle fatigue, and decreased peripheral blood flow have been suggested as possible contributing factors. There are factors known to be associated with the risk of nocturnal cramps, including:
• Over the age of 50,
Exercise, especially excessive exertion,
Leg positioning, such as prolonged sitting with the legs crossed, tight bedding that causes the toes to point down,
• Excessive alcohol consumption,
Structural disorders, for example flat feet or other foot and ankle malformations,
Medicines, eg diuretics (especially thiazide and potassium-sparing diuretics), some anti-inflammatories (eg Naproxen), long-acting beta-2 agonists, statins, opioids, raloxifene (used in osteoporosis) and lithium,
Comorbidities, eg osteoarthritis, vascular diseases, cirrhosis, diabetes, Parkinson’s disease, hypo and hyperthyroidism,
Clinical Diagnosis of Night Cramps
Description of the patient’s symptoms is usually sufficient to diagnose nocturnal leg cramps, for example, the patient may describe sudden onset of painful cramps in the muscles of the legs or feet that are awakened from sleep. A history of the disease, including a review of medications, and a focused physical exam can help identify underlying conditions that may be causing or contributing to cramps. During the examination, blood pressure measurement, neurological and vascular examination of the legs are performed.
Laboratory examinations such as electrolyte levels are not routinely required unless relevant findings are available on the history and examination. For example, it may be considered to investigate serum calcium in a patient with numbness in the feet and tetany (continuous involuntary muscle contractions).
Treatment of Nocturnal Leg Cramps
The goal of treating night cramps is symptom control unless an underlying cause is identified and managed. Lifestyle changes can be tried first to prevent cramping. If the patient remains symptomatic and symptoms are severe, pharmacological therapy may be considered. However, there is currently no pharmacological treatment for leg cramps that has been proven to be both safe and significantly effective.
Acute Management of Night Leg Cramps
Patients should be advised on what to do when they experience cramps. For example, physically stretching the cramping muscle in the calf, stretching the ankle by pulling the toes up in the direction of the shin is the most effective way to stop the cramp, but this can be painful. Passive stretching can also be effective and is less painful, and this includes relieving tension in the affected muscle with massage and postural changes. In addition, getting out of bed and walking for a short time can also provide relief.
There is no evidence of the benefit of other acute treatment strategies, but patients can have their own methods that can be encouraged if they are safe. For example, measures may be taken such as taking a hot shower or placing a wheat bag or an ice pack on the affected leg.
Lifestyle Changes of Night Leg Cramps
Encourage adequate fluid intake during the day and avoid caffeine and alcohol, especially later in the day. There is mixed evidence as to whether a short stretch before sleep is beneficial, but it can be tried. A randomized controlled study found that the frequency of nighttime leg cramps was significantly reduced after six weeks in participants who applied short stretches before bed each night.
However, one limitation of this study is that the control group did not receive a placebo intervention. In another study in which the control group used mock exercises, calf stretching was not shown to be effective in reducing the frequency or severity of night cramps. Short-term light exercise, such as walking on a stationary bike or riding a bike before bed, may be tried, but evidence of significant benefit is also lacking.
Pharmacological Interventions and Supplements of Night Leg Cramps
Mineral and vitamin supplements are unlikely to be beneficial for most people. Magnesium supplementation has many benefits in treating night cramps and may be beneficial, though the evidence is conflicting that it may reduce night cramps in pregnant women. Supplementing with both vitamin E and calcium was found to be more effective than placebo at reducing leg cramps. Over-the-counter anti-cramping formulations such as Crampeze include calcium, magnesium, high-dose B6 or B12, and some variation or combination of related supplements. Although there is anecdotal evidence that they may be beneficial for some people, there is no evidence of the benefit of these preparations.
There is limited evidence that nortriptyline, diltiazem, orphenadrine, verapamil, or gabapentin (non-subsidized) may be effective for night cramps and may be considered in patients with severe symptoms. Although there is evidence that it is effective in treating night cramps, it is no longer recommended due to safety concerns. If drugs are used, they should be started at the lowest possible dose and discontinued if no significant benefit is seen.
Quinine Treatment for Nighttime Leg Cramps
Quinine has traditionally been used at low doses (200 – 300 mg / day) for nighttime leg cramps, effective in reducing the frequency and severity of cramps. However, it is no longer recommended for nighttime leg cramps due to concerns about its safety. In 2007, Medsafe issued a warning stating that the risk-benefit ratio of quinine for leg cramps no longer supports its use and that manufacturers should relieve leg cramps as an indicator for quinine.
The main concern with quinine is the potentially fatal risk of thrombocytopenia. Drug-related thrombocytopenia is thought to be due to a peculiar hypersensitivity reaction. And therefore, it can occur unpredictably immediately after treatment or years later. Other hypersensitivity reactions associated with quinine include hemolytic uremic syndrome, diffuse intravascular coagulation, and acute kidney injury. It is significantly toxic at high doses and can cause cardiac arrhythmias, blindness, and seizures, while having significant interactions with many other drugs. The frequency of serious side effects is estimated to be 2% to 4%.
Quinine is also found in tonic water, and some people use it as a remedy for nighttime leg cramps. However, Medsafe cautioned that even low doses of quinine, such as those found in 500 mL of tonic water, have been shown to cause severe thrombocytopenia.
Author: Ozlem Guvenc Agaoglu