Overview
11 DESCRIPTION Modafinil, USP is wakefulness-promoting agent for oral administration. Modafinil, USP is a racemic compound. The chemical name for modafinil, USP is 2-[(diphenylmethyl)sulfinyl]acetamide. The molecular formula is C 15 H 15 NO 2 S and the molecular weight is 273.35. The chemical structure is: Modafinil, USP is a white to off-white, crystalline powder that is practically insoluble in...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism(s) through which modafinil promotes wakefulness is unknown. Modafinil has wake-promoting actions similar to sympathomimetic agents including amphetamine and methylphenidate, although the 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. Modafinil is not a direct- or indirect-acting dopamine receptor agonist. However, in vitro , modafinil binds to the dopamine transporter and inhibits dopamine reuptake.
Indications
- 1 INDICATIONS AND USAGE Modafinil tablets are indicated to improve wakefulness in adult patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea (OSA), or shift work disorder (SWD). Limitations of Use In OSA, modafinil 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 and during treatment with modafinil tablets for...
Common Doses
- 200 mg
- 400 mg
Dosage
2 DOSAGE AND ADMINISTRATION The recommended dosage of modafinil tablets for each indication is as follows: • Narcolepsy or OSA: 200 mg once a day in the morning. ( 2.1 ) • SWD: 200 mg once a day, taken approximately one hour prior to start of the work shift. ( 2.2 ) • Severe Hepatic Impairment: reduce dose to half the recommended dose. ( 2.3 , 12.3 ) • Geriatric Patients: consider lower dose. ( 2.4 , 12.3 ) 2.1 Dosage in Narcolepsy and Obstructive Sleep Apnea (OSA) The recommended dosage of modafinil tablets for patients with narcolepsy or OSA is 200 mg taken orally once a day as a single...
Contraindications
- 4 CONTRAINDICATIONS Modafinil is contraindicated in patients with known hypersensitivity to modafinil or armodafinil or its inactive ingredients [see Warnings and Precautions ( 5.1 , 5.2 , 5.3 )] . Modafinil is contraindicated in patients with known hypersensitivity to modafinil or armodafinil. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are described elsewhere in the labeling: • Serious Rash, including Stevens-Johnson Syndrome [see Warnings and Precautions ( 5.1 )] • Angioedema and Anaphylaxis Reactions [see Warnings and Precautions ( 5.2 )] • Multi-organ Hypersensitivity 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.
Interactions
- 7 DRUG INTERACTIONS Effects of Modafinil 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 modafinil 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 modafinil [see Clinical Pharmacology ( 12.3 )] . The effectiveness of steroidal contraceptives may be reduced when used with modafinil and for one month after discontinuation of therapy.