Drug Interactions between abrocitinib and atorvastatin

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of atorvastatin. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. When a single 40 mg dose of atorvastatin was coadministered with 240 mL of grapefruit juice, atorvastatin peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 16% and 37%, respectively. Greater increases in Cmax (up to 71%) and/or AUC (up to 2.5 fold) have been reported with excessive consumption of grapefruit juice (>=750 mL to 1.2 liters per day). Clinically, high levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death.

ADJUST DOSING INTERVAL: Fibres such as oat bran and pectin may diminish the pharmacologic effects of HMG-CoA reductase inhibitors by interfering with their absorption from the gastrointestinal tract.

MANAGEMENT: Patients receiving therapy with atorvastatin should limit their consumption of grapefruit juice to no more than 1 liter per day. Patients should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed. In addition, patients should either refrain from the use of oat bran and pectin or, if concurrent use cannot be avoided, to separate the administration times by at least 2 to 4 hours.

MONITOR: Smoking during treatment with abrocitinib may increase the risk of major adverse cardiovascular events (MACE) and the risk of developing malignancies. During abrocitinib clinical studies, current or past smokers had an additional increased risk of overall malignancies. Also, abrocitinib may increase patients' risk of MACE, including myocardial infarction, stroke, and cardiovascular death.

Administration of abrocitinib with high-fat, high-calorie food increased abrocitinib peak plasma concentration (Cmax) and systemic exposure (AUC) by 29% and 26%, respectively, and prolonged the time to reach Cmax by 2 hours. These changes are not considered clinically relevant.

MANAGEMENT: Caution is advised if abrocitinib is prescribed to current or past smokers. Patients should be informed about the symptoms of serious cardiovascular events and the steps to take if they occur. The manufacturer recommends discontinuing abrocitinib in patients that have experienced a myocardial infarction or stroke. Abrocitinib may be taken with or without food.