Drug Interaction Report

MONITOR: Coadministration with inhibitors of CYP450 1A2, 2C19, and/or 3A4 may increase the plasma concentrations of stiripentol, which has been shown in vitro to undergo phase I metabolism via these pathways.

MANAGEMENT: Caution is advised when stiripentol is used with CYP450 1A2, 2C19, and/or 3A4 inhibitors. Patients should be monitored for potentially increased adverse effects such as anorexia, nausea, vomiting, weight loss, somnolence, dizziness, confusion, difficulty concentrating, ataxia, hypotonia, tremor, hyperkinesia, dysarthria, suicidal ideation/behaviour, neutropenia, and thrombocytopenia. Dosage adjustments for stiripentol or alternative treatments may be required if an interaction is suspected.

GENERALLY AVOID: Taking stiripentol on an empty stomach may reduce its oral bioavailability. Stiripentol degrades rapidly when exposed to gastric acid in an empty stomach.

GENERALLY AVOID: Alcohol may potentiate the depressant effects of stiripentol on the central nervous system. Concomitant use may result in increased sedation and dizziness as well as impairment of psychomotor skills.

GENERALLY AVOID: It is not known whether stiripentol may reduce theophylline and caffeine metabolism, as data on the potential for inhibition of CYP450 1A2 are limited. Consumption of foods and nutritional products such as cola drinks (which contain significant quantities of caffeine) and chocolate (which contains caffeine and trace amounts of theophylline) may be unsafe during treatment with stiripentol, particularly in children.

MANAGEMENT: Stiripentol should be taken during a meal for optimal absorption; however, it should not be taken with milk, dairy products (e.g., yogurt, soft cream cheese), fruit juice, or carbonated beverages. Patients should be advised to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until they know how the medication affects them. Food and beverages that may contain caffeine or theophylline such as colas, chocolate, coffee, tea, or energy drinks should also be avoided during treatment with stiripentol.