Drug Interactions between finasteride / tadalafil and vericiguat

GENERALLY AVOID: Additive hypotensive effects may occur when phosphodiesterase-5 (PDE5) inhibitors such as tadalafil are used with alcohol, as both are mild systemic vasodilators. In clinical pharmacology studies, more subjects administered alcohol at a dose of 0.7 g/kg (equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male; consumed within 10 minutes in study subjects, providing blood alcohol levels of 0.08%) in combination with tadalafil 10 or 20 mg single doses had clinically significant decreases in blood pressure than with alcohol alone. There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g/kg (equivalent to approximately 4 ounces of 80-proof vodka in an 80-kg male), orthostatic hypotension was not observed, dizziness occurred with similar frequency relative to alcohol alone, and the hypotensive effects of alcohol were not potentiated. Neither tadalafil nor alcohol affected the plasma concentrations of the other.

GENERALLY AVOID: Coadministration with grapefruit juice is likely to increase the plasma concentrations of tadalafil, which is primarily metabolized by CYP450 3A4. However, the interaction has not been studied. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients taking tadalafil should avoid consuming large amounts of alcohol (for example, 5 units or more), which may increase the potential for orthostatic signs and symptoms including increase in heart rate, decrease in standing blood pressure, dizziness, and headache. It may also be appropriate to avoid consuming large amounts of grapefruit juice.

ADJUST DOSING INTERVAL: Administration of vericiguat with food reduces its pharmacokinetic variability and increases its exposure. Vericiguat is less soluble at neutral pH than at acidic pH. Administration of vericiguat with a high-fat, high-calorie meal or low-fat, high-carbohydrate meal increased time to reach peak plasma concentration (Tmax) from about 1 hour (fasted) to about 4 hours (fed) and increased vericiguat systemic exposure (AUC) by 19% and peak plasma concentration (Cmax) by 9% for the 5 mg tablet and by 44% (AUC) and 41% (Cmax) for the 10 mg tablet as compared with the fasted state. Concurrent treatment with drugs that increase gastric pH, such as proton pump inhibitors or antacids, decrease vericiguat AUC by about 30%. Co-treatment with drugs that increase gastric pH did not affect vericiguat exposure in patients with heart failure when vericiguat was taken as directed with food.

MANAGEMENT: Administer vericiguat with food to ensure maximal exposure and decrease pharmacokinetic variability.