Ciprofloxacin with Olanzapine Interaction Details

Brand Names Associated with Ciprofloxacin

Brand Names Associated with Olanzapine

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Dec 03, 2023

Interaction Effect

Increased OLANZapine exposure, an increased risk of OLANZapine toxicity (increased sedation, orthostatic hypotension) and an increased risk of QT interval prolongation

Interaction Summary

Concomitant use of OLANZapine (CYP1A2 substrate) with a strong CYP1A2 inhibitor (eg, ciprofloxacin) increases OLANZapine exposure, which may increase the risk of adverse reactions. Additionally, coadministration of OLANZapine with other QT prolonging drugs like ciprofloxacin may increase the risk of QT interval prolongation . In a case report, coadministration of ciprofloxacin 250 mg twice daily for one week increased OLANZapine plasma concentration without signs or symptoms of OLANZapine intoxication . Consider reducing the dosage of the OLANZapine when used concomitantly .

Severity

Major

Onset

Unspecified

Evidence

Probable

How To Manage Interaction

Concomitant use of OLANZapine, a CYP1A2 substrate, with a strong CYP1A2 inhibitor (eg, ciprofloxacin) increases OLANZapine exposure, which may increase the risk of adverse reactions. Consider reducing the dosage of the OLANZapine when used concomitantly. Additionally, coadministration of OLANZapine with other QT prolonging drugs like ciprofloxacin may increase the risk of QT interval prolongation .

Mechanism Of Interaction

Inhibition of CYP1A2-mediated OLANZapine metabolism by ciprofloxacin; additive QT interval prolongation

Literature Reports

A) Fluvoxamine, a strong CYP1A2 inhibitor, decreased the clearance of OLANZapine. A mean increase in OLANZapine Cmax 54% was observed in female nonsmokers and 77% in male smokers. The mean increase in OLANZapine AUC in female nonsmokers and male smokers is 52% and 108%, respectively .

B) A 54-year-old female was admitted to the hospital with suicidal ideation and medications included OLANZapine 10 mg at bedtime, nefazodone 100 mg twice daily, atenolol 25 mg daily, levothyroxine 0.25 mg daily, and phenytoin 100 mg twice daily. Nefazodone was tapered off prior to electroconvulsive therapy, and ciprofloxacin 250 mg twice daily for seven days was initiated for a suspected urinary tract infection. Immediately before the last dose of ciprofloxacin, OLANZapine plasma concentration was 32.6 ng/mL (104.3 nanomol/L), and it decreased by more than 50% to 14.6 ng/mL (46.7 nanomol/L) when measured 3 days after completion of ciprofloxacin. Although this patient did not experience any adverse effects associated with the increased OLANZapine level, higher doses of ciprofloxacin could potentially cause more inhibition of OLANZapine metabolism .

Ciprofloxacin Overview

• Ciprofloxacin is used to treat or prevent certain infections caused by bacteria such as pneumonia; gonorrhea (a sexually transmitted disease); typhoid fever (a serious infection that is common in developing countries); infectious diarrhea (infections that cause severe diarrhea); and infections of the skin, bone, joint, abdomen (stomach area), and prostate (male reproductive gland), Ciprofloxacin is also used to treat or prevent plague (a serious infection that may be spread on purpose as part of a bioterror attack) and inhalation anthrax (a serious infection that may be spread by anthrax germs in the air on purpose as part of a bioterror attack). Ciprofloxacin may also be used to treat bronchitis, sinus infections, or urinary tract infections but should not be used for bronchitis and sinus infections, or certain types of urinary tract infections if there are other treatment options. Ciprofloxacin extended-release (long-acting) tablets are used to treat kidney and urinary tract infections; however, some types of urinary tract infections should only be treated with ciprofloxacin extended release tablets if no other treatment options are available. Ciprofloxacin is in a class of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.

• Antibiotics such as ciprofloxacin will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

Olanzapine Overview

• 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:

• 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.