Drug Interactions between Sarafem and voclosporin

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of voclosporin. The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Because voclosporin prolongs the QT interval in a dose-dependent manner, high plasma levels of voclosporin may increase the risk of ventricular arrhythmias such as ventricular tachycardia, ventricular fibrillation, and torsade de pointes. In drug interaction studies, coadministration with multiple doses of moderate CYP450 3A4 inhibitors fluconazole or diltiazem is predicted to increase the peak plasma concentration (Cmax) and the area under the 12-hour plasma concentration-time curve (AUC 0-12) of voclosporin by approximately 2- and 3-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. 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. In addition, moderate-to-high dietary intake of potassium, especially salt substitutes, may increase the risk of hyperkalemia in some patients who are using voclosporin, which has been reported with the use of voclosporin. Patients with diabetes, heart failure, dehydration, or renal insufficiency have a greater risk of developing hyperkalemia.

ADJUST DOSING INTERVAL: Consumption of food can decrease the rate and extent of gastrointestinal absorption of voclosporin. When administered with either low- or high-fat meals, the peak plasma concentration (Cmax) of voclosporin decreased by 29% to 53% and systemic exposure (AUC) decreased by 15% to 25%.

MANAGEMENT: Patients receiving voclosporin therapy should be advised to avoid consumption of grapefruit or grapefruit juice. Voclosporin therapy should be administered at least 1 hour before or 2 hours after meals. Patients should also receive dietary counseling and be advised to not use potassium-containing salt substitutes or over-the-counter potassium supplements without consulting their doctor. If salt substitutes are used concurrently, regular monitoring of serum potassium levels is recommended. Patients should also be advised to seek medical attention if they experience symptoms of hyperkalemia such as weakness, irregular heartbeat, confusion, tingling of the extremities, or feelings of heaviness in the legs.

Switch to consumer interaction data

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

Switch to consumer interaction data