Drug General Information (ID: DDIU3M9B0Z)
Drug Name			Famotidine		Drug Info		Rilpivirine		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiulcer Agents				Antiviral Agents
Structure

Mechanism of Famotidine-Rilpivirine Interaction (Severity Level: Major)
Altered gastric pH Click to Show/Hide Mechanism Graph
Drug Name		Famotidine				Rilpivirine
Mechanism		Gastric alkalinizer				Gastric pH sensitive
Key Mechanism Factor 1
		Factor Name		Gastric pH
		Factor Description		The normal pH range of gastric acid is between 1.5 and 3.5 and is highly acidic, consisting mainly of hydrochloric acid. Changes in the pH of the stomach can alter the absorption of drugs.
Mechanism Description		Decreased absorption of Rilpivirine due to altered gastric pH caused by Famotidine

Recommended Action
Management		To minimize the risk of reduced viral susceptibility and resistance development associated with subtherapeutic levels of rilpivirine, H2-receptor antagonists should be administered at least 12 hours before or 4 hours after the rilpivirine dose.

References
1	Product Information. Edurant (rilpivirine). Tibotec Pharmaceuticals, Titusville, NJ.