Drug General Information (ID: DDI679KZQH)
Drug Name			Pantoprazole		Drug Info		Erlotinib		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Antiulcer Agents				Antineoplastics
Structure

Mechanism of Pantoprazole-Erlotinib Interaction (Severity Level: Major)
Altered gastric pH Click to Show/Hide Mechanism Graph
Drug Name		Pantoprazole				Erlotinib
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 Erlotinib due to altered gastric pH caused by Pantoprazole

Recommended Action
Management		The concomitant use of erlotinib with proton pump inhibitors should generally be avoided. If acid-suppression therapy is required during erlotinib treatment, an H2-receptor antagonist such as ranitidine may be considered. Available pharmacokinetic data suggest that erlotinib should be administered once a day, at least 2 hours before or 10 hours after dosing of the H2-receptor antagonist. Additionally, the lowest effective dosage of the H2-receptor antagonist should be prescribed.

References
1	Cerner Multum, Inc. "Australian Product Information.".
2	Cerner Multum, Inc. "UK Summary of Product Characteristics.".
3	Duong S, Leung M "Should the concomitant use of erlotinib and acid-reducing agents be avoided? The drug interaction between erlotinib and acid-reducing agents." J Oncol Pharm Pract 17 (2011): 448-52. [PMID: 20716581]
4	Product Information. Tarceva (erlotinib). Genentech, South San Francisco, CA.