The precise mechanism of action of modafinil for narcolepsy and other sleep disorders remains unclear. Although modafinil may have interactions with neurotransmitter systems, its exact mode of action is not fully understood.
From laboratory research, modafinil has little to no affinity for serotonin or norepinephrine transporters and does not directly interact with these systems. However, studies have shown that elevated concentrations of norepinephrine and serotonin can occur as an indirect effect following modafinil administration due to increased extracellular dopamine activity. Unlike traditional psychostimulant drugs, such as cocaine or amphetamine, modafinil shows low potential for causing euphoria due to differences in how it interacts with dopamine transporters at a cellular level.
In addition to its influence on dopaminergic pathways, modafinil may impact other neurotransmitter systems, such as orexin or hypocretin. Orexin neurons play a crucial role in promoting wakefulness and regulating arousal states. Modafinil may increase signaling within hypothalamic orexin pathways, potentially contributing to its wake-promoting effects.