Drug Interactions between asciminib and aspirin / caffeine / dihydrocodeine

MONITOR: Coadministration with asciminib may increase the plasma concentrations of drugs that are primarily metabolized by the CYP450 3A4 isoenzyme. The mechanism is reduced clearance due to inhibition of CYP450 3A4 by asciminib. When midazolam, a sensitive CYP450 3A4 substrate, was coadministered with asciminib 40 mg twice daily, midazolam peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 11% and 28%, respectively. Likewise, the Cmax and AUC of midazolam increased by 17% and 24%, respectively, following coadministration with asciminib at 80 mg once daily, but increased by 58% and 88%, respectively, following coadministration with asciminib at 200 mg twice daily. These results suggest weak inhibition of CYP450 3A4 by asciminib.

MANAGEMENT: Caution is advised when asciminib is used concomitantly with drugs that are substrates of CYP450 3A4, particularly sensitive substrates or those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever asciminib is added to or withdrawn from therapy. The prescribing information recommends closely monitoring for the development of adverse reactions in patients receiving asciminib therapy at 80 mg total daily dose with certain CYP450 3A4 substrates where minimal concentration changes may lead to serious or life-threatening toxicities, and avoiding coadministration of these drugs with asciminib at the maximum recommended dosage of 200 mg twice daily. The prescribing information for concomitant medications should be consulted to assess the benefits versus risks of coadministration of a weak CYP450 3A4 inhibitor like asciminib and for any dosage adjustments that may be required.

One study has reported that coadministration of caffeine and aspirin lead to a 25% increase in the rate of appearance and 17% increase in maximum concentration of salicylate in the plasma. A significantly higher area under the plasma concentration time curve of salicylate was also reported when both drugs were administered together. The exact mechanism of this interaction has not been specified. Physicians and patients should be aware that coadministration of aspirin and caffeine may lead to higher salicylate levels faster.