Omeprazole with Indinavir Interaction Details

Brand Names Associated with Omeprazole

Brand Names Associated with Indinavir

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 05, 2023

Interaction Effect

Reduced indinavir exposure with reduced efficacy

Interaction Summary

Coadministration of indinavir and omeprazole may significantly decrease indinavir bioavailability and exposure resulting in loss of efficacy of indinavir. A pharmacokinetic analysis study showed a significant decrease in the AUC of indinavir when coadministered with omeprazole, but a higher AUC of indinavir with the addition of ritonavir 200 mg. The mechanism of action is thought to be a decrease in pH-dependent indinavir bioavailability by omeprazole. Caution should be used when using omeprazole concomitantly with indinavir. If concurrent therapy is required, addition of ritonavir to therapy should be considered to increase indinavir exposure.

Severity

Major

Onset

Delayed

Evidence

Established

How To Manage Interaction

Use caution when prescribing omeprazole to patients who take indinavir. The combination of indinavir and omeprazole may lead to decreased indinavir exposure with reduced efficacy of indinavir. If concurrent therapy is required, addition of ritonavir to therapy should be considered to increase indinavir exposure.

Mechanism Of Interaction

Decrease in pH-dependent indinavir bioavailability by omeprazole

Literature Reports

A) In a prospective, randomized, placebo-controlled, single-dose crossover study (n=14) of HIV negative patients to evaluate the effect of two different doses of omeprazole on indinavir pharmacokinetics, the coadministration of omeprazole 20 mg or 40 mg significantly reduced the mean AUC from 30 mg x hr/L (95% confidence interval (CI), 21.9 to 41.1 mg x hr/L) to 19.7 mg x hr/L (95% CI, 14.6 to 26.8 mg x hr/L) or 16 mg x hr/L (95% CI, 11.8 to 21.7 mg x hr/L), respectively (p less than 0.002). Patients were randomized to receive placebo, omeprazole 20 mg, or omeprazole 40 mg for 7 days followed by a single dose of indinavir 800 mg alone or in combination with 200 mg of ritonavir. The single-dose pharmacokinetic profile of the 800 mg dose of indinavir alone or in combination with 200 mg of ritonavir was studied. The mean indinavir AUC was significantly increased from 30 mg x hr/L (95% CI, 21.9 to 41.1 mg x hr/L) to 46.6 mg x hr/L (95% CI, 34 to 63.8 mg x hr/L) with the addition of ritonavir 200 mg to indinavir 800 mg in combination with omeprazole 40 mg; mean omeprazole concentrations were not significantly altered (p less than 0.02). This higher indinavir AUC was also significantly greater than the indinavir AUC when given with and after placebo. There was no statistically significant change noted in the Cmax or Tmax of indinavir after the administration of omeprazole. When ritonavir was added to indinavir, the Cmax of indinavir was not significantly altered, but the Tmax of indinavir was significantly increased .

Omeprazole Overview

• Prescription omeprazole is used alone or with other medications to treat the symptoms of gastroesophageal reflux disease (GERD), a condition in which backward flow of acid from the stomach causes heartburn and possible injury of the esophagus (the tube between the throat and stomach) in adults and children 1 year of age and older. Prescription omeprazole is used to treat damage from GERD in adults and children 1 month of age and older. Prescription omeprazole is used to allow the esophagus to heal and prevent further damage to the esophagus in adults and children 1 year of age and older with GERD. Prescription omeprazole is also used to treat conditions in which the stomach produces too much acid such as Zollinger-Ellison syndrome in adults. Prescription omeprazole is also used to treat ulcers (sores in the lining of the stomach or intestine) and it is also used with other medications to treat and prevent the return of ulcers caused by a certain type of bacteria (H. pylori) in adults. Nonprescription (over-the-counter) omeprazole is used to treat frequent heartburn (heartburn that occurs at least 2 or more days a week) in adults. Omeprazole is in a class of medications called proton-pump inhibitors. It works by decreasing the amount of acid made in the stomach.

Indinavir Overview

• Indinavir is used along with other medications to treat human immunodeficiency virus (HIV) infection. Indinavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although indinavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other lifestyle changes may decrease the risk of transmitting the HIV virus to other people.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.