Metoprolol with Rifampin Interaction Details

Brand Names Associated with Metoprolol

Brand Names Associated with Rifampin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 05, 2023

Interaction Effect

Reduced metoprolol efficacy

Interaction Summary

Rifampin induces certain CYP450 enzymes and has been reported to accelerate the metabolism of some beta blockers including metoprolol, resulting in reduced plasma concentrations  and decreased efficacy. Serum concentration of metoprolol was decreased in all patients with chronic kidney disease initiating rifampin and loss of hypertensive control required dosage increases in most . Dosages of drugs metabolized by these enzymes may require adjustment when starting or stopping concomitantly administered rifampin . Consider monitoring blood pressure to ensure continued antihypertensive efficacy during concomitant use or use an alternative to rifampin, when possible .

Severity

Major

Onset

Unspecified

Evidence

Established

How To Manage Interaction

Rifampin induces certain CYP450 enzymes and has been reported to accelerate the metabolism of some beta blockers, including metoprolol . Dosages of drugs metabolized by these enzymes may require adjustment when starting or stopping concomitantly administered rifampin . Consider monitoring blood pressure to ensure continued antihypertensive efficacy during concomitant use or use an alternative to rifampin, when possible .

Mechanism Of Interaction

Induction of CYP-mediated metabolism of metoprolol by rifampin

Literature Reports

A) In a cohort study in patients with chronic kidney disease stage 5 and hypertension controlled by stable antihypertensive therapy (N=24), addition of rifampin 450 or 600 mg/day for treatment of newly diagnosed TB as part of a standard 4-drug protocol necessitated a significant dosage increase of antihypertensive medication in 83.3% of patients to maintain blood pressure (BP) of 140/90 mm Hg or less. A hypertensive crisis occurred in 46% of patients, including hypertensive emergency in 3 patients. Mean time to first dosage increase was 6.5 days and mean time to crisis was 9.1 days. Rifampin had to be withdrawn in 2 patients who could not achieve BP control despite maximal doses. There was a mean 91.9% decrease in serum metoprolol levels in 4 patients with available serum concentrations. Metoprolol levels became undetectable in 3 of the patients. Initial metoprolol doses and baseline serum levels were 50 mg/day (n=2; levels, 45.9 and 84 nanograms/mL [ng/mL]), 25 mg/day (n=1; level, 27.2 ng/mL), and 100 mg/day (n=1; level, 49.5 ng/mL) .

B) Twelve male volunteers received oral metoprolol 100 mg as a single dose before rifampin, immediately after a 15-day course of rifampin 600 mg daily, and again 15 days after the discontinuation of rifampin. Results showed that rifampin reduced plasma concentrations of metoprolol in all of the subjects, with the area under the concentration-time curve (AUC) averaging a 33% decrease. This effect had reverted to initial values within 15 days after the discontinuation of rifampin. The changes in metoprolol kinetics were attributed to induction of hepatic microsomal enzymes by rifampin .

Metoprolol Overview

• Metoprolol is used alone or in combination with other medications to treat high blood pressure. It also is used to treat chronic (long-term) angina (chest pain). Metoprolol is also used to improve survival after a heart attack. Metoprolol also is used in combination with other medications to treat heart failure. Metoprolol is in a class of medications called beta blockers. It works by relaxing blood vessels and slowing heart rate to improve blood flow and decrease blood pressure.

• 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.

Rifampin Overview

• Rifampin is used with other medications to treat tuberculosis (TB; a serious infection that affects the lungs and sometimes other parts of the body). Rifampin is also used to treat some people who have Neisseria meningitidis (a type of bacteria that can cause a serious infection called meningitis) infections in their noses or throats. These people have not developed symptoms of the disease, and this treatment is used to prevent them from infecting other people. Rifampin should not be used to treat people who have developed symptoms of meningitis. Rifampin is in a class of medications called antimycobacterials. It works by killing the bacteria that cause infection.

• Antibiotics such as rifampin 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.

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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.