The non-stimulant wake-promoting medications approved for use in narcolepsy include modafinil and armodafinil. Their pharmacology is not completely understood, but these medications "appear to influence brain chemistry that increases wakefulness."[5] They elevate hypothalamic histamine levels,[31] and they are known to bind to the dopamine transporter, thereby inhibiting dopamine reuptake. Modafinil can cause uncomfortable side effects, including nausea, headache, and a dry mouth for some patients, while other patients report no noticeable improvement even on relatively high dosages.[32] They may also "interact with low-dose contraceptives, potentially reducing efficacy, although the scientific data supporting this claim is weak and rests on poorly documented anecdotes."[11] New histamine-directed wake-promoting medications are currently under development (see Histamine-directed medications).