Modafinil Sandoz (Modafinil)

• Modafinil is a wakefulness‑promoting eugeroic that acts on central neurotransmitter systems to treat excessive daytime sleepiness associated with several sleep‑related disorders.
• Narcolepsy: reduces the frequency of daytime sleep attacks, improves sustained alertness, and supports better functional performance.
• Obstructive sleep apnea‑related excessive daytime sleepiness: lessens residual sleepiness in patients already receiving optimal CPAP or other apnea therapy, enhancing daytime functioning.
• Shift work sleep disorder: promotes wakefulness during scheduled night or early‑morning shifts, helping to align alertness with work demands.

• Modafinil enhances wakefulness primarily by inhibiting the reuptake of dopamine, thereby increasing extracellular dopamine concentrations in brain regions that regulate alertness. It also modulates orexinergic pathways, stimulates histamine release, and influences other neurotransmitters such as norepinephrine and serotonin, collectively contributing to its central nervous system activating effects without directly binding to typical stimulant receptors. The net result is a modest increase in cortical arousal and reduced propensity for sleep.

Modafinil may be associated with a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Headache: mild to moderate headache is frequently reported.
• Nausea: occasional gastrointestinal upset or nausea.
• Insomnia: difficulty falling or staying asleep.
• Dry mouth: reduced salivation leading to a dry oral cavity.

Serious or Rare Side Effects

• Psychiatric symptoms: emergence of anxiety, agitation, or rare psychosis.
• Severe rash: including Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Cardiac events: rare cases of arrhythmia or myocardial infarction.

• When prescribing Modafinil, clinicians should consider several precautionary measures to ensure safe use.
• Cardiovascular assessment: evaluate blood pressure and heart disease history before initiation.
• Psychiatric history: monitor for anxiety, depression, or prior psychosis.
• Drug dependence: avoid in patients with a history of substance misuse.
• Pregnancy and lactation: use only if potential benefit justifies potential risk, as safety data are limited.
• Concomitant medications: assess for interactions that may affect cardiac rhythm or hepatic metabolism.
• Store at ambient temperature: keep below 25 °C, protect from moisture and keep in original container.

Modafinil can affect the pharmacokinetics of several medicines; awareness of key interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Cytochrome P450 3A4 inducers (e.g., carbamazepine, phenytoin, rifampicin): may markedly reduce Modafinil plasma levels, decreasing efficacy.
• CYP2C19 inhibitors (e.g., fluvoxamine): can increase Modafinil exposure, raising risk of side effects.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: Modafinil may reduce hormonal contraceptive effectiveness; advise additional non‑hormonal methods.
• Anticoagulants (e.g., warfarin): may alter INR; monitor coagulation parameters.
• Antidepressants (e.g., SSRIs): may increase risk of serotonin syndrome; observe for symptoms.