Restless Legs Syndrome and Periodic Limb Movement Disorder

Common Causes

Mostly no known cause
Iron-deficiency anemia (amount of hemoglobin is less than normal)
Pregnancy, menstruation, and menopause
Chronic renal failure
Osteoarthritis of the hips and knees
Drugs, for example, caffeine, tricyclic antidepressants, selective serotonin reuptake inhibitors, and dopamine receptor-blocking drugs
Neurological disorders
Peripheral neuropathies (disorder affecting any segment of the nervous system)
Various causes of myelitis
Postpolio syndrome
Diseases of the spinal cord
Disorders of the lumbar/sacral region

Treatment guidelines

Restless legs syndrome and periodic limb movement disorder are treated with 3 classes of medications.

Anti-parkinsonian drugs, such as levodopa/carbidopa, bromocriptine, ropinirole (Requip), pergolide (Permax), and pramipexole (Mirapex), have been used.
Benzodiazepines, especially clonazepam have been effective. Other benzodiazepines used have included diazepam, temazepam, and lorazepam.
Opiates, such as codeine, oxycodone, methadone, and propoxyphene, are other drugs that have been used.
Dopamine agonists, such as levodopa or pergolide, may be effective, but the effectiveness may not last, and some individuals are unable to tolerate side effects.
Other drugs that have shown effectiveness include clonidine or anticonvulsants, such as carbamazepine, valproate, and gabapentin.
Several studies have reported efficacy of different medications belonging to the aforementioned groups, but comparative studies between various classes of drugs or even individual drugs do not exist. Therefore, persons should receive one drug, and, if no response is noted, they should be placed on another drug of the same class or a different class.
A combination of drugs may be required in more severe cases. Some persons who do not respond to benzodiazepines alone, levodopa alone, or a combination of both may be treated with opiates.
One should receive the smallest possible dose and should be closely observed for the development of dependency. Experience reveals that the incidence of abuse, tolerance, or addiction to opiates or benzodiazepines in persons with severe restless legs syndrome appears to be insignificant. The disabling condition of severe restless legs syndrome must be treated aggressively.
Restless legs syndrome and periodic limb movement disorder are chronic conditions that require long-term drug therapy. Some persons may develop symptoms of restless legs during the daytime, and this may be treated with controlled release of levodopa/carbidopa administered in the evening and morning.
Avoidance of certain drugs, such as tricyclic antidepressants, fluoxetine, or lithium, may be helpful because these drugs generally worsen the symptoms of restless legs syndrome and periodic limb movement disorder.
A decrease in body iron stores, as indicated by serum ferritin (an iron-protein complex) levels less than 50 mcg/L, should be corrected with iron supplementation. Oral iron is preferred but takes a long time to provide improvement, because gastrointestinal absorption is low. However, replenishment is an effective treatment strategy for iron-deficiency anemia and may also relieve symptoms of restless legs syndrome and periodic limb movement disorder.