Modafinil

Other CNS Drugs · Non-amphetamine wake promoter

Indications

Excessive daytime sleepiness associated with narcolepsy and obstructive sleep apnoea/hypopnoea syndrome.

Dosage

Adults: 200-400 mg daily in two divided doses In the morning and at noon, or as a single dose in the morning. Elderly: Initially 100 mg daily: max 400 mg daily In absence of renal or hepatic impairment. Children: Not recommended.

Adverse Effects

Nervousness, excitation, aggression, insomnia, personality disorders, anorexia, headache, CNS stimulation, euphoria, GI upset, dry mouth, palpitations, tachycardia, hypertension, tremor, pruritus, buccofacial dyskinesia. Increase in alkaline phosphatase, anxiety, dizziness, somnolence, depression, abnormal thinking, confusion, paraesthesia, blurred vision, vasodilatation, asthenia, chest pain, altered LFTs.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: Moderate to severe hypertension, arrhythmia, history of left ventricular hypertrophy, ischaemic ECG changes, chest pain, manifestations of mitral valve prolapse associated with CNS stimulants. Use adequate contraception. Precautions: Severe hepatic or renal failure. Patients with major anxiety must be in specialist unit. Monitor BP and heart rate in hypertensive patients. History of psychiatric disorders, alcohol or drug abuse. Monitor patients for abnormal behaviour or thoughts. Risk of serious skin or hypersensitivity reactions and psychiatric symptoms. Perform ECG before starting treatment. Reassess need for treatment periodically.

Interactions

Oral contraceptives, anticonvulsants, antidepressants, anticoagulants, substrates of CYP3A4/5 (e.g., cyclosporin, protease inhibitors, buspirone, midazolam, calcium channel blockers, statins) or CYP2C19 (e.g., diazepam, propranolol, omeprazole).

Advice to Patient

Take on an empty stomach. Do not take medication within 1 hour of eating food. Maintain healthy sleeping pattern. Do not share medication with anyone else. Avoid excessive intake of foods, beverages, and OTC medications that contain caffeine. Empty bladder before taking medication. If you have diabetes, check your blood glucose level regularly. Females bearing child-potential should use an alternative method of contraception along with regular contraceptive method during therapy and for upto 1 month after therapy. On start of therapy or change of dosage, patient should be watched carefully for suicidal tendency by caregiver or family.

Pharmacokinetics

Modafinil is a racemic compound (10% S-isomer and 90% R-isomer at steady state) whose enantiomers have different pharmacokinetics. Metabolism: Hepatic. Half-life elimination: Effective half-life: 15 hours. Time to peak, serum: 2 to 4 hours; may be delayed approx. 1 hour with food. Excretion: Urine (80% as metabolites, <10% as unchanged drug); feces (1%).

Brands with this active ingredient

• Dowvigil
• Evigil
• V-Zac

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.