Drug General Information (ID: DDIZSUI687)
Drug Name			Ranitidine (bismuth citrate)		Drug Info		Dacomitinib		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiulcer Agents				Antineoplastics/Her2 Inhibitors
Structure

Mechanism of Ranitidine (bismuth citrate)-Dacomitinib Interaction (Severity Level: Moderate)
Altered gastric pH Click to Show/Hide Mechanism Graph
Drug Name		Ranitidine (bismuth citrate)				Dacomitinib
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 Dacomitinib due to altered gastric pH caused by Ranitidine (bismuth citrate)

Recommended Action
Management		The manufacturer recommends taking dacomitinib at least 6 hours before or 10 hours after H2-receptor antagonists. As an alternative, locally-acting antacids may be considered. Concomitant use of dacomitinib with PPIs should generally be avoided.

References
1	Cerner Multum, Inc. "UK Summary of Product Characteristics.".
2	Product Information. Vizimpro (dacomitinib). Pfizer U.S. Pharmaceuticals Group, New York, NY.