Omeprazole with Olanzapine Interaction Details
Brand Names Associated with Omeprazole
- Omeprazole
- Prilosec®
- Prilosec® OTC
- Talicia (as a combination product containing Amoxicillin, Omeprazole, Rifabutin)
- Zegerid® (as a combination product containing Omeprazole, Sodium Bicarbonate)
- Zegerid® OTC (as a combination product containing Omeprazole, Sodium Bicarbonate)
Brand Names Associated with Olanzapine
- Olanzapine
- Symbyax® (as a combination product containing Fluoxetine, Olanzapine )
- Zyprexa®
- Zyprexa® Zydis
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 03, 2023
Interaction Effect
Reduced OLANZapine exposure and reduced efficacy of OLANZapine
Interaction Summary
Concomitant use of OLANZapine with omeprazole may cause CYP1A2 induction and may increase OLANZapine clearance. Consider dosage increase of OLANZapine in patients receiving concomitant treatment with omeprazole. In a case report where after carBAMazepine discontinuation (a CYP1A2 inducer) there was a 114% increase in OLANZapine serum concentrations .
Severity
Major
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Concomitant use of OLANZapine with omeprazole may cause CYP1A2 induction and may increase OLANZapine clearance. Consider dosage increase of OLANZapine in patients receiving concomitant treatment with omeprazole.
Mechanism Of Interaction
Induction of CYP1A2-mediated metabolism of OLANZapine
Literature Reports
A) Coadministration of OLANZapine, a CYP1A2 substrate, with carBAMazepine 200 mg twice daily (a CYP1A2 inducer) caused an approximate 50% increased clearance of OLANZapine .
B) A 23-year-old female with paranoid schizophrenia was treated with carBAMazepine 600 mg daily for aggressive outbursts along with perphenazine, her only medication on admission. OLANZapine 15 mg daily was started and her psychiatric symptoms improved over the next 3 weeks. Because her aggressive outbursts were still present, carBAMazepine was discontinued due to lack of efficacy. The day prior to carBAMazepine discontinuation, the OLANZapine serum concentration was 21 ng/mL. Over the next few weeks following carBAMazepine discontinuation, the OLANZapine concentration increased by 114% to 45 ng/mL. The dose of OLANZapine was decreased to 10 mg daily and a corresponding fall in the OLANZapine level occurred .
Omeprazole Overview
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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.
Olanzapine Overview
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Olanzapine is used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions) in adults and teenagers 13 years of age and older. It is also used to treat bipolar disorder (manic depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods) in adults and teenagers 13 years of age and older. Olanzapine is in a class of medications called atypical antipsychotics. It works by changing the activity of certain natural substances in the brain.
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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:
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.