Clarithromycin with Guanfacine Interaction Details

Brand Names Associated with Clarithromycin

  • Biaxin® Filmtab®
  • Biaxin® Granules
  • Biaxin® XL Filmtab
  • Biaxin® XL Pac
  • Clarithromycin

Brand Names Associated with Guanfacine

  • Guanfacine
  • Intuniv®
  • Tenex®

Medical Content Editor
Last updated Nov 08, 2023

Curious for more information about this interaction?

Ask our pharmacists directly!

Reach out to us

Interaction Effect

Increased guanfacine exposure

Interaction Summary

Concomitant use of guanfacine (a CYP3A4 substrate) with a strong CYP3A4 inhibitor may increase the exposure of guanfacine. When ketoconazole (a strong CYP3A4 inhibitor) was coadministered with guanfacine, the guanfacine exposure increased by over 200%. If coadministration is required, dose adjustments are necessary. When initiating guanfacine while the patient is receiving a strong CYP3A4 inhibitor or adding a strong CYP3A4 inhibitor to existing guanfacine therapy, decrease the recommended guanfacine dose by half. If continuing guanfacine while stopping a strong CYP3A4 inhibitor, increase the guanfacine dose to the recommended level.

Severity

Moderate

Onset

Unspecified

Evidence

Theoretical

How To Manage Interaction

Concomitant use of guanfacine (a CYP3A4 substrate) with a strong CYP3A4 inhibitor may increase the exposure of guanfacine. If coadministration is required, dose adjustments are necessary. When initiating guanfacine while the patient is receiving a strong CYP3A4 inhibitor or adding a strong CYP3A4 inhibitor to existing guanfacine therapy, decrease the recommended guanfacine dose by half. If continuing guanfacine while stopping a strong CYP3A4 inhibitor, increase the guanfacine dose to the recommended level.

Mechanism Of Interaction

Inhibition of CYP3A4-mediated metabolism of guanfacine

Literature Reports

A) When ketoconazole (a strong CYP3A4 inhibitor) was coadministered with guanfacine, the guanfacine Cmax and AUC increased by about 2 and 3-fold, respectively .

Clarithromycin Overview

  • Clarithromycin is used to treat certain bacterial infections, such as pneumonia (a lung infection), bronchitis (infection of the tubes leading to the lungs), and infections of the ears, sinuses, skin, and throat. It also is used to treat and prevent disseminated Mycobacterium avium complex (MAC) infection [a type of lung infection that often affects people with human immunodeficiency virus (HIV)]. It is used in combination with other medications to eliminate H. pylori, a bacterium that causes ulcers. Clarithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria.

  • Antibiotics such as clarithromycin 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.

See More information Regarding Clarithromycin

Guanfacine Overview

  • Guanfacine tablets (Tenex) are used alone or in combination with other medications to treat high blood pressure. Guanfacine extended-release (long-acting) tablets (Intuniv) are used as part of a treatment program to control symptoms of attention deficit hyperactivity disorder (ADHD; more difficulty focusing, controlling actions, and remaining still or quiet than other people who are the same age) in children. Guanfacine is in a class of medications called centrally acting alpha2A-adrenergic receptor agonists. Guanfacine treats high blood pressure by decreasing heart rate and relaxing the blood vessels so that blood can flow more easily through the body. Guanfacine extended-release tablets may treat ADHD by affecting the part of the brain that controls attention and impulsivity.

  • High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.

See More information Regarding Guanfacine

Return To Our Drug Interaction Homepage

Feedback, Question Or Comment About This Information?

Ask , our medical editor, directly! He's always more than happy to assist.

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.