Two Meds. The two main medications used today to treat narcolepsy include xyrem (sodium oxybate) which is very helpful for treating cataplexy and excessive day time sleepiness and nuvigil/provigil which is used to promote wakefullness. The current "standard of care" is to give these medications together (xyrem at night and Nuvigil by day. Other medications are used but these are the current standard.
Stimulants medicines. Stimulants are used to control the sleepiness in narcolepsy. These include methylphenidate, amphetamines, and modafinil. They all work through their effects on Dopamine pathways in the brain. They improve but do not fully control sleepiness. Other symptoms like cataplexy, sleep paralysis and hypnagogic hallucinations are controlled by rem suppressants like citalopram. Oxybate is another option.