Caution must be exercised if clinical circumstances require combining stiripentol with drugs metabolised by CYP2C19 (e. g. citalopram, omeprazole) or CYP3A4 (e. g. several HIV protease inhibitors, antihistamines, astemizole, chlorpheniramine, calcium channel blockers, statins, oral contraceptives, codeine) due to the increased risk of adverse events (see further in this section for antiepileptic drugs).