• Armodafinil is the pharmacologically active R-enantiomer of modafinil; it reaches higher plasma levels and lasts several hours longer than equal doses of racemic modafinil.
• Best taken early in the day with water and food to minimise gastrointestinal upset; late-day dosing often delays sleep onset.
• Hydration, dietary electrolytes and periodic blood-pressure checks reduce common side-effects (headache, mild hypertension, anxiety).
• Because the drug induces CYP3A4 and inhibits CYP2C19, it can lower plasma levels of hormonal contraceptives and many antiepileptics while raising levels of drugs such as diazepam or phenytoin.
• Discontinue immediately and seek care if rash, chest pain, severe anxiety, or psychosis appears – rare but documented idiosyncratic reactions including Stevens-Johnson syndrome.
• A 2-day on / 1-day off or weekend-off schedule helps slow tolerance development.
