Therapies for narcolepsy with or without cataplexy: evidence-based review.

(1) Narcolepsy is a rare disorder of unknown aetiology characterized by excessive daytime sleepiness and typically associated with cataplexy. It is extremely incapacitating, and frequently results in impaired psychosocial functioning and reduced work performance. Currently there is no cure for narcolepsy, so treatment focuses on control of symptoms.(2) Although the sympathomimetic stimulants, such as amphetamines or methylphenidate, are effective in improving excessive daytime sleepiness in patients with narcolepsy, they have the potential for dependence, have sometimes disabling sympathomimetic side-effects and are associated with tolerance.(3) To date, there is clear evidence of the efficacy of modafinil, armodafinil and sodium oxybate in patients with narcolepsy. Modafinil and armodafinil improve excessive daytime sleepiness symptoms and have little abuse potential, but have no effect on cataplexy, so other drugs, such as antidepressants, are required to control cataplexy attacks.(4) Sodium oxybate improves both excessive daytime sleepiness and cataplexy. However, there is potential for abuse and possibly dependence.