Drug Interactions between ozanimod and rifampin

GENERALLY AVOID: Concurrent use of rifampin in patients who ingest alcohol daily may result in an increased incidence of hepatotoxicity. The increase in hepatotoxicity may be due to an additive risk as both alcohol and rifampin are individually associated with this adverse reaction. However, the exact mechanism has not been established.

ADJUST DOSING INTERVAL: Administration with food may reduce oral rifampin absorption, increasing the risk of therapeutic failure or resistance. In a randomized, four-period crossover phase I study of 14 healthy male and female volunteers, the pharmacokinetics of single dose rifampin 600 mg were evaluated under fasting conditions and with a high-fat meal. Researchers observed that administration of rifampin with a high-fat meal reduced rifampin peak plasma concentration (Cmax) by 36%, nearly doubled the time to reach peak plasma concentration (Tmax) but reduced overall exposure (AUC) by only 6%.

MANAGEMENT: The manufacturer of oral forms of rifampin recommends administration on an empty stomach, 30 minutes before or 2 hours after meals. Patients should be encouraged to avoid alcohol or strictly limit their intake. Patients who use alcohol and rifampin concurrently or have a history of alcohol use disorder may require additional monitoring of their liver function during treatment with rifampin.

GENERALLY AVOID: Foods that contain large amounts of tyramine may precipitate a hypertensive crisis in patients treated with ozanimod. The proposed mechanism involves potentiation of the tyramine pressor effect due to inhibition of monoamine oxidase (MAO) by the major active metabolites of ozanimod, CC112273 and CC1084037. Monoamine oxidase in the gastrointestinal tract and liver, primarily type A (MAO-A), is the enzyme responsible for metabolizing exogenous amines such as tyramine and preventing them from being absorbed intact. Once absorbed, tyramine is metabolized to octopamine, a substance that is believed to displace norepinephrine from storage granules causing a rise in blood pressure. In vitro, CC112273 and CC1084037 inhibited MAO-B (IC50 values of 5.72 nM and 58 nM, respectively) with more than 1000-fold selectivity over MAO-A (IC50 values >10000 nM). Because of this selectivity, as well as the fact that free plasma concentrations of CC112273 and CC1084037 are less than 8% of the in vitro IC50 values for MAO-B inhibition, ozanimod is expected to have a much lower propensity to cause hypertensive crises than nonselective MAO inhibitors. However, rare cases of hypertensive crisis have occurred during clinical trials for the treatment of multiple sclerosis (MS) and ulcerative colitis (UC) and in postmarketing use. In controlled clinical trials, hypertension and blood pressure increases were reported more frequently in patients treated with ozanimod (up to 4.6% in MS patients receiving ozanimod 0.92 mg/day) than in patients treated with interferon beta-1a (MS) or placebo (UC).

Administration of ozanimod with either a high-fat, high-calorie meal (1000 calories; 50% fat) or a low-fat, low-calorie meal (300 calories; 10% fat) had no effects on ozanimod peak plasma concentration (Cmax) and systemic exposure (AUC) compared to administration under fasted conditions.

MANAGEMENT: Dietary restriction is not ordinarily required during ozanimod treatment with respect to most foods and beverages that contain tyramine, which usually include aged, fermented, cured, smoked, or pickled foods (e.g., air-dried and fermented meats or fish, aged cheeses, most soybean products, yeast extracts, red wine, beer, sauerkraut). However, certain foods like some of the aged cheeses (e.g., Boursault, Liederkrantz, Mycella, Stilton) and pickled herring may contain very high amounts of tyramine and could potentially cause a hypertensive reaction in patients taking ozanimod, even at recommended dosages, due to increased sensitivity to tyramine. Patients should be advised to avoid the intake of very high levels of tyramine (e.g., greater than 150 mg) and to promptly seek medical attention if they experience potential signs and symptoms of a hypertensive crisis such as severe headache, visual disturbances, confusion, stupor, seizures, chest pain, unexplained nausea or vomiting, and stroke-like symptoms. Blood pressure should be regularly monitored and managed accordingly. Because of the long elimination half-lives of the major active metabolites, these precautions may need to be observed for up to 3 months following the last ozanimod dose. Ozanimod can be administered with or without food.