Modafinil Orifarm (Modafinil)

Modafinil acts on central nervous system pathways that regulate wakefulness, and is approved for the following indications:

• Narcolepsy: reduces excessive daytime sleepiness and improves alertness in patients with narcolepsy.
• Obstructive sleep apnea‑related sleepiness: alleviates residual sleepiness in patients with obstructive sleep apnea who are using appropriate respiratory therapy.
• Shift work sleep disorder: helps improve wakefulness in individuals whose work schedule requires nighttime activity.

• Modafinil primarily inhibits the dopamine transporter, leading to increased extracellular dopamine concentrations in brain regions involved in arousal. It also influences other neurotransmitter systems, enhancing orexinergic signaling and modulating histamine, norepinephrine and serotonin pathways, which collectively promote wakefulness without directly stimulating adrenergic receptors. The drug’s effect on glutamatergic transmission and reduction of GABAergic inhibition further contributes to its wake‑promoting profile.

Modafinil may cause a range of adverse reactions, which are categorized by frequency.

Common Side Effects

• Headache: mild to moderate pain often occurring early in treatment.
• Nausea: transient gastrointestinal discomfort.
• Insomnia: difficulty falling or staying asleep when taken later in the day.
• Dizziness: sensation of light‑headedness or unsteadiness.

Serious or Rare Side Effects

• Severe skin reactions: such as Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Psychiatric events: including anxiety, agitation, or rare psychosis.
• Cardiovascular complications: hypertension, arrhythmia, or chest pain.
• Hepatic injury: elevated liver enzymes or hepatitis.
• Hypersensitivity: anaphylactic reactions requiring immediate medical attention.

Before prescribing Modafinil, clinicians should consider several safety aspects.

• Assess cardiovascular status: evaluate blood pressure and heart disease before initiating therapy.
• Avoid use in uncontrolled hypertension: monitor BP regularly during treatment.
• Consider renal/hepatic function: dose may need adjustment in severe impairment.
• Caution in psychiatric history: monitor for mood changes or emergence of psychosis.
• Avoid abrupt discontinuation: taper if long‑term use to reduce rebound sleepiness.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light.

Modafinil can interact with other medicines, requiring attention to the level of risk.

Major Interactions (Avoid)

• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): may increase plasma levels.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce efficacy.
• Other wakefulness agents (e.g., amphetamines): risk of excessive stimulation.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: reduced effectiveness, consider alternative contraception.
• Antidepressants (e.g., SSRIs, SNRIs): may increase risk of serotonin syndrome.
• Antihypertensives: potential additive blood pressure effects.