Drug interactions with proton pump inhibitors

Area of Science:

• Pharmacology
• Drug Metabolism
• Gastroenterology

Background:

• Omeprazole, lansoprazole, and pantoprazole are proton pump inhibitors (PPIs).
• These PPIs are primarily metabolized by the cytochrome P450 (CYP) isoform CYP2C19.
• CYP2C19 exhibits polymorphic expression, potentially influencing drug metabolism rates.

Purpose of the Study:

• To evaluate the drug interaction potential of omeprazole, lansoprazole, and pantoprazole at the cytochrome P450 level.
• To assess the clinical relevance of known drug interactions and effects on drug absorption.
• To investigate synergistic effects with antibacterial agents.

Main Methods:

• Review of existing literature on PPI metabolism and drug interactions.
• Analysis of pharmacokinetic data related to CYP2C19 metabolism.
• Assessment of clinical studies on drug absorption alterations and antibacterial synergy.

Main Results:

• The three studied proton pump inhibitors (omeprazole, lansoprazole, pantoprazole) exhibit limited drug interaction potential via CYP enzymes.
• Observed effects on cytochrome P450 activity are generally not clinically significant.
• Increased intragastric pH due to PPIs can alter the absorption of certain drugs, such as benzylpenicillin.
• Omeprazole demonstrates synergistic antibacterial effects when combined with amoxicillin or clarithromycin against Helicobacter pylori.

Conclusions:

• Omeprazole, lansoprazole, and pantoprazole are unlikely to cause clinically relevant drug interactions mediated by CYP2C19.
• Slow metabolizers of CYP2C19 are not at increased risk for significant drug interactions with these PPIs.
• PPIs can impact the absorption of other medications due to pH changes, requiring consideration.
• Combination therapy with omeprazole and specific antibiotics is effective for H. pylori eradication.