Valacyclovir with Nitisinone Interaction Details
Brand Names Associated with Valacyclovir
- Valacyclovir
- Valtrex®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 17, 2023
Interaction Effect
Increased exposure of OAT1 or OAT3 substrate and potential for adverse effects
Interaction Summary
Concomitant administration of nitisinone, an inhibitor of OAT1 and OAT3, with OAT1 or OAT3 substrates may increase substrate exposure and potential adverse effects. Monitor for potential adverse reactions related to the substrate when using concomitantly with nitisinone. When nitisinone 80 mg once daily was coadministered with a 20-mg IV dose of furosemide (an OAT1/OAT3 substrate), furosemide AUC increased by 72% and Cmax increased by 12%.
Severity
Major
Onset
Unspecified
Evidence
Probable
How To Manage Interaction
Concomitant administration of nitisinone, an inhibitor of OAT1 and OAT3, with OAT1 or OAT3 substrates may increase substrate exposure and potential adverse effects. Monitor for potential adverse reactions related to the substrate when using concomitantly with nitisinone.
Mechanism Of Interaction
Inhibition of OAT1- or OAT3-mediated metabolism by nitisinone
Literature Reports
A) When nitisinone 80 mg once daily was coadministered with a 20-mg IV dose of furosemide (an OAT1/OAT3 substrate), furosemide AUC increased by 72% and Cmax increased by 12% .
Valacyclovir Overview
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Valacyclovir is used to treat herpes zoster (shingles) and genital herpes. It does not cure herpes infections but decreases pain and itching, helps sores to heal, and prevents new ones from forming.
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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:
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.