- Last edited on September 6, 2022
Modafinil (Provigil)
Primer
Modafinil (Trade name: Provigil) is a/an wakefulness-promoting agent and CNS stimulant. It is commonly used in the treatment of sleep disorders such as narcolepsy and daytime fatigue in obstructive sleep apnea.
Pharmacokinetics
See also article: Introduction to Pharmacology
Pharmacokinetics of Modafinil
See also article: Cytochrome (CYP) P450 Metabolism
Modafinil: Cytochrome P450 Metabolism
Substrate of (Metabolized by) | 3A4 |
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Induces | 3A4, 2B6, 1A2 |
Inhibits | 2C19 |
Pharmacodynamics
Mechanism of Action
Toxicity
Indications
Dosing
Dosing for Modafinil
Starting | 100mg PO BID (at 0800 and 1200) |
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Titration | Increase by 100 mg |
Maximum | 200 mg PO BID (maximum total dose 400 mg PO daily) |
Taper | No tapering required |
Formulations
- Modafinil comes in oral formulation.
Monitoring
Contraindications
Absolute
Relative
Drug-Drug Interactions
- Co-administration of modafinil with drugs such as diazepam, phenytoin and propranolol (which are largely eliminated via CYP2C19 pathway), may increase the circulating levels of these drugs.
- For women of child-bearing age, combined oral contraceptives, transdermal patches, vaginal oral contraceptives, and progesterone contraceptives may be reduced in efficacy when taking modafinil.
- Copper intrauterine devices, levonorgestrel releasing intrauterine systems, and depot medroxyprogesterone acetate (DMPA) are not affected and should be recommended for women for whom there is this interaction.
Side Effects
Adverse Events
- There is a risk for Stevens-Johnson Syndrome and patients should be counselled on this potential risk.[1]
Clinical Pearls
Special Populations
Geriatric
See main article: Geriatric Pharmacology
Pediatric
See main article: Pediatric Pharmacology
Obstetric and Fetal
See main article: Obstetric and Fetal Pharmacology
- There is an increased risk for major congenital malformations when used during pregnancy.[2]
Medically Ill
See main article: Psychotropic Dosing in the Medically Ill