Drug General Information (ID: DDIFZ7R6EM)
Drug Name			Didanosine		Drug Info		Ketoconazole		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Anti-Hiv Agents				Antifungal Agents
Structure

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

Recommended Action
Management		Separation of doses by two hours is recommended. It may be preferable to give the ketoconazole dose first. Fluconazole does not appear to interact with didanosine. Patients should be monitored for altered antifungal effects.

References
1	May DB, Drew RH, Yedinak KC, Bartlett JA "Effect of simultaneous didanosine administration on itraconazole absorption in healthy volunteers." Pharmacotherapy 14 (1994): 509-13. [PMID: 7997384]
2	Moreno F, Hardin TC, Rimaldi MG, Graybill JR "Itraconazole-didanosine excipient interaction." JAMA 269 (1993): 1508. [PMID: 8383255]