Drug Interactions between Diacomit and lorlatinib

GENERALLY AVOID: Grapefruit and grapefruit juice may significantly increase the plasma concentrations of lorlatinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruit. Because grapefruit juice inhibits primarily intestinal rather than hepatic CYP450 3A4, the magnitude of interaction is greatest for those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability). In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients treated with lorlatinib should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. If coadministration is unavoidable, some authorities recommend reducing the initial dosage of lorlatinib from 100 mg orally once daily to 75 mg orally once daily. In patients who have had a dosage reduction to 75 mg orally once daily due to adverse reactions, the lorlatinib dosage should be further reduced to 50 mg orally once daily upon initiation of a potent CYP450 3A4 inhibitor. After 3 plasma half-lives following discontinuation of the potent CYP450 3A4 inhibitor, the lorlatinib dosage may be increased to that used prior to initiation of the inhibitor.

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.