Drug Interactions between finerenone and Fioricet

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of finerenone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit juice, but has been reported for other CYP450 3A4 inhibitors. Pharmacokinetic modeling simulations suggest that concomitant use of finerenone with 200 mg twice daily itraconazole, a potent CYP450 3A4 inhibitor, increases finerenone peak plasma concentration (Cmax) and systemic exposure (AUC) by 137% and 531%, respectively. Clarithromycin, another potent CYP450 3A4 inhibitor, given at 500 mg twice daily is predicted to increase finerenone Cmax by 125% and AUC by 428%. Additionally, drug interaction studies showed that concomitant use of finerenone with 500 mg thrice daily erythromycin, a moderate CYP450 3A4 inhibitor, increased mean finerenone Cmax and AUC by 88% and 248%, respectively. Verapamil, another moderate CYP450 3A4 inhibitor, given as a 240 mg controlled-release tablet once daily increased mean finerenone Cmax by 120% and AUC by 170%. 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. High exposure to finerenone may potentiate the risk of hyperkalemia, and the risk may be further increased with decreasing kidney function and higher baseline potassium levels.

MONITOR CLOSELY: Dietary intake of excess potassium, especially via salt substitutes, may increase the risk of hyperkalemia in patients who are using finerenone. Patients with diabetes, heart failure, dehydration, or renal insufficiency have a greater risk of developing hyperkalemia.

Administration of finerenone with high-fat, high-calorie food decreased finerenone Cmax by 19%, increased AUC by 21%, and prolonged the time to reach Cmax to 2.5 hours. These changes are not considered clinically relevant.

MANAGEMENT: Patients receiving finerenone therapy should be instructed to avoid consumption of grapefruit or grapefruit juice. In addition, patients should receive dietary counseling and be advised not to use potassium-containing salt substitutes or over-the-counter potassium supplements without consulting their physician. If salt substitutes or supplements are used concurrently, more frequent monitoring of serum potassium levels is recommended. Patients should also be advised to seek medical attention if they experience signs and symptoms of hyperkalemia such as nausea, vomiting, weakness, listlessness, tingling of the extremities, paralysis, confusion, weak pulse, and a slow or irregular heartbeat. Finerenone may be taken with or without food.

GENERALLY AVOID: Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.

MANAGEMENT: In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day. However, if acetaminophen is used, these patients should be cautioned not to exceed the recommended dosage (maximum 4 g/day in adults and children 12 years of age or older).

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.

The effect of grapefruit juice on the pharmacologic activity of caffeine is controversial. One report suggests that grapefruit juice increases the effect of caffeine. The proposed mechanism is inhibition of cytochrome P-450 metabolism of caffeine. However, a well-conducted pharmacokinetic/pharmacodynamic study did not demonstrate this effect. The clinical significance of this potential interaction is unknown.