Ranitidine Hydrochloride

Atazanavir absorption may be impaired based on known interactions with agents that increase gastric pH. Use with caution.

Delavirdine absorption may be impaired with ranitidine. Chronic use of H2-receptor antagonists with delavirdine is not recommended.

Gefitinib exposure was reduced by 44% when coadministered with ranitidine and sodium bicarbonate. Use with caution.

Glipizide exposure increased by 34% following a single 150-mg dose of oral ranitidine. Use appropriate clinical monitoring when initiating or discontinuing ranitidine.

Oral ketoconazole exposure reduced by up to 95% when coadministered with ranitidine regimens maintaining gastric pH above 6. Degree of interaction at usual doses is unknown.

Oral midazolam exposure increased up to 65% with ranitidine 150 mg twice daily. Monitor for excessive or prolonged sedation.

Procainamide: Ranitidine, a substrate of the renal organic cation transport system, may affect the clearance of other drugs eliminated by this route. High doses of ranitidine (e.g., such as those used in the treatment of Zollinger-Ellison syndrome) have been shown to reduce the renal excretion of procainamide and N-acetylprocainamide resulting in increased plasma levels of these drugs. Although this interaction is unlikely to be clinically relevant at usual ranitidine doses, it may be prudent to monitor for procainamide toxicity when administered with oral ranitidine at a dose exceeding 300 mg per day.

Triazolam exposure was increased by approximately 30% when coadministered with ranitidine due to altered gastric pH affecting absorption.

Ranitidine may alter prothrombin time in patients on concurrent warfarin therapy. Close monitoring of prothrombin time is recommended during concurrent treatment.