Doxycycline with Rifampin Interaction Details

Brand Names Associated with Doxycycline

Brand Names Associated with Rifampin

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

Interaction Effect

Reduced doxycycline serum concentrations and potential loss of doxycycline efficacy

Interaction Summary

Concurrent rifampin may increase doxycycline clearance resulting in reduced doxycycline bioavailability and potential loss of doxycycline therapeutic efficacy.

Severity

Moderate

Onset

Delayed

Evidence

Probable

How To Manage Interaction

Monitor patient response to combined rifampin and doxycycline treatment as lowered doxycycline effectiveness should be anticipated. Alternatively, consider administering doxycycline in combination with streptomycin.

Mechanism Of Interaction

Increased doxycycline clearance induced by rifampin

Literature Reports

A) Serum concentrations of doxycycline were lower when rifampin was coadministered compared with coadministration with streptomycin, in a study of 20 patients with brucellosis was conducted. Half of the study group was treated with the combination of doxycycline and rifampin and the other half with doxycycline and streptomycin. There was a significant inverse correlation between serum concentrations of rifampin and those of doxycycline. Clearance of doxycycline was 130% higher in the rifampin group compared with the streptomycin group. Doxycycline area under the concentration-time curve (AUC) and half-life (t1/2) were significantly lower in the group receiving concomitant rifampin compared with values for the group given streptomycin. Two of 10 patients in the rifampin group experienced therapeutic failure or relapse; all patients in the streptomycin group were cured . Rifampin is a known inducer of hepatic metabolism. To date, the elimination process of doxycycline has not been fully defined; however, much of its clearance appears to be via hepatic metabolism. The mechanism of this interaction is likely to be rifampin induction of cytochrome P450 enzymes involved in doxycycline metabolism.

Doxycycline Overview

• Doxycycline is used to treat a variety of infections caused by certain types of bacteria. Doxycycline is also used to treat or prevent anthrax (a serious infection that may be spread on purpose as part of a bioterror attack) in people who may have been exposed to anthrax in the air and to treat plague and tuleramia (serious infections that may be spread on purpose as part of a bioterror attack). It is also used to prevent malaria. Doxycycline is also used along with other medications to treat acne and rosacea (a skin disease that causes redness, flushing, and pimples on the face). Doxycycline (Oracea) is used only to treat pimples and bumps caused by rosacea. Doxycycline is in a class of medications called tetracycline antibiotics. It works to treat infections by preventing the growth and spread of bacteria. It works to treat acne by killing the bacteria that infects pores and decreasing a certain natural oily substance that causes acne. It works to treat rosacea by decreasing the inflammation that causes this condition.

• Antibiotics such as doxycycline 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.

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.