Famotidine with Probenecid Interaction Details

Brand Names Associated with Famotidine

Brand Names Associated with Probenecid

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 13, 2023

Interaction Effect

Increased famotidine concentration

Interaction Summary

Concomitant administration of probenecid and famotidine has been reported to result in increases in the area under the serum concentration time curve and maximum concentration of famotidine. This increase in famotidine concentration was due to a decline in renal tubular secretion.

Severity

Minor

Onset

Rapid

Evidence

Probable

How To Manage Interaction

Although the clinical significance of this interaction has not been established, a lower dosage of famotidine may be required to produce a therapeutic effect. Increases in the famotidine dose should be made cautiously and in small increments when probenecid is being coadministered.

Mechanism Of Interaction

Decreased famotidine clearance

Literature Reports

A) A study found that coadministration of probenecid (1500 mg) with famotidine (20 mg) resulted in significant increases in area under the famotidine serum concentration-time curve up to 10 hours (from 420 to 760 ng-h/mL) and maximum serum concentration (from 73 to 112 ng/mL), with decreases in renal clearance of famotidine. After receiving an oral dose of famotidine 20 mg and determination of resulting pharmacokinetic parameters, 8 healthy subjects serving as their own controls underwent a 30-day washout period before the concomitant administration of probenecid 1500 mg (1000 mg 2 hrs prior, 250 mg 1 hr prior, and 250 mg simultaneously) and famotidine 20 mg. The data strongly support the ability of probenecid to inhibit the renal tubular secretion of famotidine .

Famotidine Overview

• Prescription famotidine is used to treat ulcers (sores on the lining of the stomach or small intestine); gastroesophageal reflux disease (GERD, a condition in which backward flow of acid from the stomach causes heartburn and injury of the esophagus [tube that connects the mouth and stomach]); and conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome (tumors in the pancreas or small intestine that cause increased production of stomach acid). Over-the-counter famotidine is used to prevent and treat heartburn due to acid indigestion and sour stomach caused by eating or drinking certain foods or drinks. Famotidine is in a class of medications called H₂ blockers. It works by decreasing the amount of acid made in the stomach.

Probenecid Overview

• Probenecid is used to treat chronic gout and gouty arthritis. It is used to prevent attacks related to gout, not treat them once they occur. It acts on the kidneys to help the body eliminate uric acid. Probenecid is also used to make certain antibiotics more effective by preventing the body from passing them in the urine.

• This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

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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.