Armodafinil (2 brand names, 1 dosage form, 1 route)
Available dosage forms: TABLET.
Routes of administration: ORAL.
Brand Names
- ARMODAFINIL
- NUVIGIL
Indications and Usage
Armodafinil tablets are indicated to improve wakefulness in adult patients with excessive sleepiness associated with obstructive sleep apnea (OSA), narcolepsy, or shift work disorder (SWD). Limitations of Use In OSA, armodafinil tablets are indicated to treat excessive sleepiness and not as treatment for the underlying obstruction. If continuous positive airway pressure (CPAP) is the treatment of choice for a patient, a maximal effort to treat with CPAP for an adequate period of time should be made prior to initiating armodafinil tablets for excessive sleepiness.
Contraindications
Armodafinil tablets are contraindicated in patients with known hypersensitivity to modafinil or armodafinil or its inactive ingredients [see Warnings and Precautions (5.1, 5.2, 5.3)].
Adverse Reactions
The following serious adverse reactions are described below and elsewhere in the labeling: •Serious Dermatologic Reactions [see Warnings and Precautions (5.1)] •Drug Reaction with Eosinophilia and System Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions (5.2)] •Angioedema and Anaphylaxis Reactions [see Warnings and Precautions (5.3)] •Persistent Sleepiness [see Warnings and Precautions (5.4)] •Psychiatric Symptoms [see Warnings and Precautions (5.5)] •Effects on Ability to Drive and Use Machinery [see Warnings and Precautions (5.6)] •Cardiovascular Events [see Warnings and Precautions (5.7)]
Drug Interactions
Effects of Armodafinil on CYP3A4/5 Substrates The clearance of drugs that are substrates for CYP3A4/5 (e.g., steroidal contraceptives, cyclosporine, midazolam, and triazolam) may be increased by armodafinil via induction of metabolic enzymes, which results in lower systemic exposure. Dosage adjustment of these drugs should be considered when these drugs are used concomitantly with armodafinil [see Clinical Pharmacology (12.3)]. The effectiveness of steroidal contraceptives may be reduced when used with armodafinil and for one month after discontinuation of therapy. Alternative or concomitant methods of contraception are recommended for patients taking steroidal contraceptives (e.g., ethinyl estradiol) when treated concomitantly with armodafinil and for one month after discontinuation of armodafinil treatment. Blood levels of cyclosporine may be reduced when used with armodafinil. Monitoring of circulating cyclosporine concentrations and appropriate dosage adjustment for cyclosporine should be considered when used concomitantly with armodafinil. Effects of Armodafinil on CYP2C19 Substrates Elimination of drugs that are substrates for CYP2C19 (e.g., phenytoin, diazepam, propranolol, omeprazole, and clomipramine) may be prolonged by armodafinil via inhibition of metabolic enzymes, with resultant higher systemic exposure. Dose reduction of these drugs may be required when these drugs are used concomitantly with armodafinil. Warfarin More frequent monitoring of prothrombin times/INR should be considered whenever armodafinil is coadministered with warfarin [see Clinical Pharmacology (12.3)]. Monoamine Oxidase (MAO) Inhibitors Caution should be used when concomitantly administering MAO inhibitors and armodafinil.
Mechanism of Action
The mechanism(s) through which armodafinil promotes wakefulness is unknown. Armodafinil (R-modafinil) has pharmacological properties similar to those of modafinil (a mixture of R- and S-modafinil), to the extent tested in animal and in vitro studies. The R- ‑and S-enantiomers have similar pharmacological actions in animals. Armodafinil and modafinil have wake-promoting actions similar to sympathomimetic agents including amphetamine and methylphenidate, although their pharmacologic profile is not identical to that of the sympathomimetic amines. Modafinil-induced wakefulness can be attenuated by the α1-adrenergic receptor antagonist, prazosin; however, modafinil is inactive in other in vitro assay systems known to be responsive to α-adrenergic agonists such as the rat vas deferens preparation. Armodafinil is an indirect dopamine receptor agonist; both armodafinil and modafinil bind in vitro to the dopamine transporter and inhibit dopamine reuptake. For modafinil, this activity has been associated in vivo with increased extracellular dopamine levels in some brain regions of animals. In genetically engineered mice lacking the dopamine transporter (DAT), modafinil lacked wake-promoting activity, suggesting that this activity was DAT-dependent. However, the wake-promoting effects of modafinil, unlike those of amphetamine, were not antagonized by the dopamine receptor antagonist haloperidol in rats. In addition, alpha-methyl-p-tyrosine, a dopamine synthesis inhibitor, blocks the action of amphetamine, but does not block locomotor activity induced by modafinil. In addition to its wake-promoting effects and ability to increase locomotor activity in animals, modafinil produces psychoactive and euphoric effects, alterations in mood, perception, thinking, and feelings typical of other CNS stimulants in humans. Modafinil has reinforcing properties, as evidenced by its self-administration in monkeys previously trained to self-administer cocaine; modafinil was also partially discr
Overdosage
Fatal overdoses involving modafinil alone or involving armodafinil or modafinil in combination with other drugs have been reported in the postmarketing setting. Symptoms most often accompanying armodafinil or modafinil overdose, alone or in combination with other drugs, have included anxiety, dyspnea, insomnia; central nervous system symptoms such as restlessness, disorientation, confusion, excitation and hallucination; digestive changes such as nausea and diarrhea; and cardiovascular changes such as tachycardia, bradycardia, hypertension, and chest pain. No specific antidote exists for the toxic effects of a armodafinil overdose. Such overdoses should be managed with primarily supportive care, including cardiovascular monitoring.