Ephedrine is a central nervous system stimulant used to treat breathing problems (as a bronchodilator), nasal congestion (as a decongestant), low blood pressure problems (orthostatic hypotension), or myasthenia gravis. This drug has also been used to treat certain sleep disorders (narcolepsy), menstrual problems (dysmenorrhea), or urine-control problems (incontinence or enuresis).