Buspirone with Erythromycin Interaction Details

Brand Names Associated with Buspirone

Brand Names Associated with Erythromycin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Mar 06, 2024

Interaction Effect

Increased busPIRone plasma concentrations; increased busPIRone side effects (impaired psychomotor performance, sedation)

Interaction Summary

Peak plasma concentrations and bioavailability of busPIRone were significantly increased by erythromycin in eight healthy females in a double blind randomized study[1]. If concomitant administration is necessary, low doses of busPIRone (2.5 mg twice daily) should be utilized and further dose adjustments should be based on clinical assessment [2].

Severity

Moderate

Onset

Rapid

Evidence

Probable

How To Manage Interaction

Erythromycin should be avoided in patients treated with busPIRone. If this combination cannot be avoided, low doses of busPIRone (2.5 mg twice daily) are recommended. Also monitor the patient for side effects of busPIRone.

Mechanism Of Interaction

Inhibition by erythromycin of cytochrome P450 3A4-mediated metabolism of busPIRone

Literature Reports

A) Peak plasma concentrations and bioavailability of busPIRone were significantly increased by erythromycin in eight healthy females in a double blind randomized study. Patients were randomized to receive either erythromycin 500 mg three times daily or placebo for four days. On the fourth day a single dose of busPIRone 10 mg was given with the last dose of erythromycin. Compared to placebo, the average peak plasma level of busPIRone was increased from 1 ng/mL to 5 ng/mL (3 nanomoles/L to 13 nanomoles/L) by erythromycin. The average area under the plasma concentration time curve from time zero to infinity was increased from 3.3 ng/mL h for placebo to 19.5 ng/mL h with erythromycin. The elimination half-life of busPIRone was not effected by erythromycin. This may be because the erythromycin was discontinued when the busPIRone was given. Performance in psychomotor tests was significantly impaired in subjects receiving both erythromycin and busPIRone compared to subjects receiving busPIRone and placebo. Erythromycin should be avoided in patients treated with busPIRone [1].

References

1 ) Kivisto KT, Lamberg TS, Kantola T, et al: Plasma buspirone concentrations are greatly increased by erythromycin and itraconazole. Clin Pharmacol Ther 1997; 86:348-354.

2 ) Product Information: BuSpar(R), buspirone. Bristol-Myers Squibb Company, Princeton, NJ, 1998.

Buspirone Overview

• Buspirone is used to treat anxiety disorders or in the short-term treatment of symptoms of anxiety. Buspirone is in a class of medications called anxiolytics. It works by changing the amounts of certain natural substances in the brain.

Erythromycin Overview

• Erythromycin is used to treat certain infections caused by bacteria, such as infections of the respiratory tract, including bronchitis, pneumonia, Legionnaires' disease (a type of lung infection), and pertussis (whooping cough; a serious infection that can cause severe coughing); diphtheria (a serious infection in the throat); sexually transmitted diseases (STD), including syphilis; and ear, intestine, gynecological, urinary tract, and skin infections. It also is used to prevent recurrent rheumatic fever. Erythromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria.

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

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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.