Drug Interactions between palovarotene and Pyrukynd

GENERALLY AVOID: Theoretically, the coadministration with grapefruit juice may increase the plasma concentrations of mitapivat. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The extent and clinical significance are unknown. 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. Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability.

MANAGEMENT: Although clinical data are lacking, it may be advisable to avoid or limit consumption of grapefruit or grapefruit juice during therapy with mitapivat if possible. If concomitant use is unavoidable, close monitoring of hemoglobin levels and for the development of adverse effects such as atrial fibrillation, gastroenteritis, rib fracture, musculoskeletal pain, arthralgia, increased urate levels, and in males, for decreased estrone and estradiol levels, is recommended. The product labeling should be consulted for dose adjustments of mitapivat in the event of the development of adverse reaction or hemoglobin levels above normal.

GENERALLY AVOID: Grapefruit, pomelo, grapefruit hybrids, and juices or supplements containing these fruits may increase the plasma concentrations of palovarotene. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in these fruits. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with these fruits. Concomitant use of erythromycin, a moderate CYP450 3A4 inhibitor, with palovarotene at steady-state plasma levels increased its peak plasma concentration (Cmax) and systemic exposure (AUC) by 1.6 and 2.5-fold, respectively. 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. Increased concentrations of palovarotene may increase the risk of adverse effects such as dry skin, dry lips, alopecia, pruritus, erythema, paronychia, cellulitis, decubitus ulcer, xerophthalmia, night blindness, depression, mood alterations, and pseudotumour cerebri (benign intracranial hypertension).

ADJUST DOSE: Food increases oral absorption of palovarotene.

MANAGEMENT: The manufacturer advises that concomitant use of palovarotene with grapefruit, pomelo, grapefruit hybrids and juices or supplements containing these fruits should be avoided. To ensure maximal absorption, palovarotene should be administered with food.