armodafinil

Armodafinil is a wakefulness-promoting agent and the (R)-enantiomer of modafinil. It is marketed under brand names such as Nuvigil and is available by prescription in many countries. Armodafinil is indicated for excessive daytime sleepiness associated with narcolepsy, shift work sleep disorder, and obstructive sleep apnea/hypopnea syndrome.

Pharmacology and mechanism of action are not fully understood. It is believed to promote wakefulness primarily by inhibiting the dopamine transporter, leading to increased extracellular dopamine in the central nervous system. It may affect other neurotransmitter systems as well. Compared with the racemic form modafinil, armodafinil generally has a longer functional half-life, supporting once-daily dosing for many patients.

Dosing and administration typically involve 150 mg to 250 mg once daily in the morning for narcolepsy or obstructive sleep apnea/hypopnea syndrome. For shift work sleep disorder, a dose of 150 mg is often taken about one hour before the start of the work shift. The maximum recommended daily dose is 250 mg. The drug is approved for adults and is not approved for children under 17. Dose adjustments may be needed for elderly patients or those with hepatic impairment.

Safety and adverse effects include common reactions such as headache, nausea, dry mouth, dizziness, and insomnia. Rare but serious adverse events can include severe skin reactions such as Stevens–Johnson syndrome. Cautions include a history of psychiatric disorders, hepatic impairment, and potential drug interactions. Armodafinil can interact with hormonal contraceptives by reducing their effectiveness, and use of alcohol should be approached with caution. It is a Schedule IV controlled substance in the United States and is regulated as a prescription medication in other jurisdictions.