Diazepam with Fosamprenavir Interaction Details


Brand Names Associated with Diazepam

  • Diazepam
  • Diazepam Intensol®
  • Valium®
  • Valrelease®

Brand Names Associated with Fosamprenavir

  • Fosamprenavir
  • Lexiva®

Medical Content Editor
Last updated Nov 19, 2023


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Interaction Effect

An increased risk of diazepam toxicity (excessive sedation, confusion, respiratory depression)


Interaction Summary

Plasma concentrations of diazepam may be elevated by the concurrent administration of fosamprenavir. Amprenavir, the active metabolite of fosamprenavir, and diazepam are both metabolized by CYP3A4 isoenzymes, and amprenavir is also an inhibitor of CYP3A4. Competition for metabolism and/or inhibition of metabolism could result in an increased plasma concentration of diazepam. Although clinical significance is unknown, a decrease in diazepam dosing may be warranted.


Severity

Moderate


Onset

Unspecified


Evidence

Theoretical


How To Manage Interaction

Caution should be exercised if diazepam and fosamprenavir are administered concurrently. Monitor the patient for excessive benzodiazepine adverse effects, such as confusion, excessive sedation, and respiratory depression. A decrease in diazepam dose may be necessary.


Mechanism Of Interaction

Inhibition of CYP3A4-mediated diazepam metabolism by amprenavir, the active metabolite of fosamprenavir

Diazepam Overview

  • Diazepam is used to relieve anxiety and to control agitation caused by alcohol withdrawal. It is also used along with other medications to control muscle spasms and spasticity caused by certain neurological disorders such as cerebral palsy (condition that causes difficulty with movement and balance), paraplegia (inability to move parts of the body), athetosis (abnormal muscle contractions), and stiff-man syndrome (a rare disorder with muscle rigidity and stiffness). Diazepam is also used along with other medications to control seizures. Diazepam is in a class of medications called benzodiazepines. It works by calming abnormal overactivity in the brain.

See More information Regarding Diazepam

Fosamprenavir Overview

  • Fosamprenavir is used along with other medications to treat human immunodeficiency virus (HIV) infection. Fosamprenavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although fosamprenavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other life-style changes may decrease the risk of transmitting the HIV virus to other people.

See More information Regarding Fosamprenavir

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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.