Fentanyl with Rifampin Interaction Details
Brand Names Associated with Fentanyl
- Abstral®
- Actiq®
- Fentanyl
- Fentora®
- Onsolis®
Brand Names Associated with Rifampin
- Rifadin®
- Rifamate® (as a combination product containing Isoniazid, Rifampin)
- Rifampin
- Rifater® (as a combination product containing Isoniazid, Pyrazinamide, Rifampin)
- Rimactane®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 31, 2023
Interaction Effect
Decreased plasma concentrations of fentanyl
Interaction Summary
Exercise caution with coadministration of fentanyl and a CYP3A4 inducer as this may result in decreased efficacy of fentanyl. If concomitant use is required, monitor for signs of opioid withdrawal and consider dose adjustments. Upon discontinuation of the CYP3A4 inducer, plasma concentrations of fentanyl will increase, which may increase or prolong the therapeutic and adverse effects of fentanyl, including the risk of serious respiratory depression.
Severity
Major
Onset
Unspecified
Evidence
Established
How To Manage Interaction
Coadministration of fentanyl and a CYP3A4 inducer should be undertaken with caution as this may result in decreased efficacy of fentanyl. If concomitant use is required, monitor for signs of opioid withdrawal and consider dose adjustments. Upon discontinuation of the CYP3A4 inducer, plasma concentrations of fentanyl will increase, which may increase or prolong the therapeutic and adverse effects of fentanyl, including the risk of serious respiratory depression.
Mechanism Of Interaction
Induction of CYP3A4-mediated metabolism of fentanyl
Literature Reports
A) A 64-year-old man receiving rifampin was not able to achieve pain control with optimized doses of transdermal fentanyl and rescue pain medications until he was switched to morphine. The patient, who had colon cancer, was receiving rifampin 450 mg/day as part of an antitubercular regimen for pulmonary tuberculosis. Despite dose increases from 0.6 mg/day of fentanyl up to 2.5 mg/day along with rescue medication, pain control was not achieved. When fentanyl was switched to sustained-release oral morphine at a relative analgesic dose to fentanyl (180 mg/day), pain control was achieved. Subsequently, however, the patient experienced a disturbance in consciousness, which was considered to be a morphine side effect. Based on the Naranjo probability scale, rifampin possibly caused the lack of response to fentanyl .
Fentanyl Overview
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Fentanyl is used to treat breakthrough pain (sudden episodes of pain that occur despite round the clock treatment with pain medication) in cancer patients at least 18 years of age (or at least 16 years of age if using Actiq brand lozenges) who are taking regularly scheduled doses of another narcotic (opiate) pain medication, and who are tolerant (used to the effects of the medication) to narcotic pain medications. Fentanyl is in a class of medications called narcotic (opiate) analgesics. It works by changing the way the brain and nervous system respond to pain.
Rifampin Overview
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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.
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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:
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.