Drug Interactions between metformin and Viberzi

GENERALLY AVOID: Alcohol can potentiate the effect of metformin on lactate metabolism and increase the risk of lactic acidosis. In addition, alcohol may cause hypoglycemia or hyperglycemia in patients with diabetes. Although hypoglycemia rarely occurs during treatment with metformin alone, the risk may increase with acute consumption of alcohol. Even modest amounts can lower blood sugar significantly, especially when the alcohol is ingested on an empty stomach or following exercise. The mechanism involves inhibition of both gluconeogenesis as well as the counter-regulatory response to hypoglycemia. Episodes of hypoglycemia may last for 8 to 12 hours after ethanol ingestion. By contrast, chronic alcohol abuse can cause impaired glucose tolerance and hyperglycemia. Moderate alcohol consumption generally does not affect blood glucose levels in patients with well controlled diabetes.

Food may have varying effects on the absorption of metformin from immediate-release versus extended-release formulations. When a single 850 mg dose of immediate-release metformin was administered with food, mean peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 40% and 25%, respectively, and time to peak plasma concentration (Tmax) increased by 35 minutes compared to administration under fasting conditions. By contrast, administration of extended-release metformin with food increased AUC by 50% without affecting Cmax or Tmax, and both high- and low-fat meals had the same effect. These data may not be applicable to formulations that contain metformin with other oral antidiabetic agents.

MANAGEMENT: Metformin should be taken with meals, and excessive alcohol intake should be avoided during treatment. Diabetes patients in general should avoid consuming alcohol if their blood glucose is not well controlled, or if they have hypertriglyceridemia, neuropathy, or pancreatitis. Alcohol should not be consumed on an empty stomach or following exercise, as it may increase the risk of hypoglycemia. Patients should contact their physician immediately if they experience potential signs and symptoms of lactic acidosis such as malaise, myalgia, respiratory distress, increasing somnolence, and nonspecific abdominal distress (especially after stabilization of metformin therapy, when gastrointestinal symptoms are uncommon). With more marked acidosis, there may also be associated hypothermia, hypotension, and resistant bradyarrhythmias. Metformin should be withdrawn promptly if lactic acidosis is suspected. Serum electrolytes, ketones, blood glucose, blood pH, lactate levels, and blood metformin levels may be useful in establishing a diagnosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia).

CONTRAINDICATED: Consumption of more than 3 alcoholic beverages per day may increase the risk of acute pancreatitis during treatment with eluxadoline. Pancreatitis has been reported rarely during clinical trials of eluxadoline, and may or may not be related to sphincter of Oddi spasm.

ADJUST DOSING INTERVAL: High-fat meals may reduce the oral bioavailability of eluxadoline. In 28 healthy volunteers, administration of a single 100 mg dose of eluxadoline with a high-fat meal (approximately 800 to 1000 total calories, 50% from fat) decreased eluxadoline peak plasma concentration (Cmax) and systemic exposure (AUC) by 50% and 60%, respectively, compared to administration in the fasted state. There was no significant effect on the time to peak concentration (Tmax). The clinical relevance of this interaction is unknown. It should be noted that phase 3 clinical trials were conducted under fed conditions.

MANAGEMENT: Chronic or acute excessive use of alcohol should be avoided during treatment with eluxadoline. Alcoholism, alcohol abuse, alcohol addiction, and consumption of more than 3 alcoholic beverages per day are considered contraindications to the use of eluxadoline. The product labeling recommends taking eluxadoline with food. Patients should be advised to stop taking eluxadoline and seek medical attention if they experience potential symptoms of pancreatitis such as persistent nausea, vomiting, abdominal tenderness, and upper abdominal pain, especially that which is made worse after eating or radiates to the back or shoulders.