Ketoconazole and Lansoprazole interaction
Ketoconazole and Lansoprazole: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Ketoconazole label · effective 2026-07-07
Drugs that may decrease ketoconazole plasma concentrations Drugs that reduce the gastric acidity (e.g., acid neutralizing medicines such as aluminum hydroxide, or acid secretion suppressors such as H 2 -receptor antagonists and proton pump inhibitors) impair the absorption of ketoconazole from ketoconazole tablets.
From the Lansoprazole (Prevacid) label · effective 2025-07-08
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Lansoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of lansoprazole is expected when used concomitantly with strong inhibitors [see Clinical Pharmacology (12.3) ] .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.