Pravastatin with Efavirenz Interaction Details
Brand Names Associated with Pravastatin
- Pravachol®
- Pravastatin
Brand Names Associated with Efavirenz
- Atripla® (as a combination product containing Efavirenz, Emtricitabine, Tenofovir)
- Efavirenz
- Sustiva®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 11, 2023
Interaction Effect
Decreased pravastatin plasma concentrations
Interaction Summary
When 13 patients were given pravastatin 40 mg/day for 4 days together with efavirenz 600 mg/day for 15 days, the Cmax, AUC, and Cmin of pravastatin was reduced by 32%, 44%, and 19%, respectively. In an open-label, multidose pharmacokinetic study, coadministration of efavirenz and pravastatin in healthy, HIV-seronegative volunteers resulted in decreased pravastatin AUC values and Cmax concentrations by approximately 40% and 18%, respectively . Although this did not appear to have detrimental effects on the lipid-lowering ability of pravastatin, further long-term studies at steady-state concentrations of both drugs are needed. Efavirenz may potentially decrease the effectiveness of pravastatin necessitating an increase dose, change in therapy, and/or addition of other lipid-lowering agents.
Severity
Moderate
Onset
Delayed
Evidence
Established
How To Manage Interaction
Concomitant administration of efavirenz and pravastatin has resulted in decreased pravastatin plasma concentrations, which may lower efficacy. If these agents are administered concurrently, consider dose adjustments based on clinical response.
Mechanism Of Interaction
Unknown
Literature Reports
A) In an open-label pharmacokinetic study, coadministration of efavirenz and pravastatin in healthy, HIV-seronegative subjects resulted in decreased pravastatin AUC values and plasma concentrations. Subjects (n=13) received oral pravastatin 40 mg every night for 4 days. From day 5 to 18, efavirenz 600 mg was administered every night at bedtime. Pravastatin was restarted on day 15 through 18. Blood samples were taken to determine the pravastatin AUC from 0 to 24 hours before and after coadministration of efavirenz. Pravastatin AUC values decreased by a median of 40.4%, from 96.32 nanograms (ng) x hr/mL (95% CI, 30.05 to 161.04 ng x hr/mL) on day 3 to 42.65 ng x hr/mL (95% CI, 26.42 to 61.83 ng x hr/mL) on day 18 (p=0.0046). Median Cmax values for pravastatin were 28.46 ng/mL (95% CI, 4.74 to 59.39 ng/mL) and 14.78 ng/mL (95% CI, 8.64 to 35.07 ng/mL) for days 3 and 18, respectively (median within-subject change of -18.2%, p=0.0327). LDL changed by a median of -23.5 mg/dL (95% CI, -32 to -10) with pravastatin alone. The effect on LDL was attenuated when efavirenz was coadministered for 4 days (-10.5 mg/dL; 95% CI, -27 to 0); however, the difference in LDL changes with and without efavirenz was not significantly different (p=0.0774). Pravastatin does not alter the metabolism of efavirenz. A study limitation was the short duration (4 days) of efavirenz and pravastatin coadministration, which limits the ability to evaluate the full potential for a pharmacodynamic interaction .
Pravastatin Overview
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Pravastatin is used together with diet, weight-loss, and exercise to reduce the risk of heart attack and stroke and to decrease the chance that heart surgery will be needed in people who have heart disease or who are at risk of developing heart disease. Pravastatin is also used to reduce the amount of fatty substances such as low-density lipoprotein (LDL) cholesterol ('bad cholesterol') and triglycerides in the blood and to increase the amount of high-density lipoprotein (HDL) cholesterol ('good cholesterol') in the blood. Pravastatin is in a class of medications called HMG-CoA reductase inhibitors (statins). It works by slowing the production of cholesterol in the body to decrease the amount of cholesterol that may build up on the walls of the arteries and block blood flow to the heart, brain, and other parts of the body.
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Accumulation of cholesterol and fats along the walls of your arteries (a process known as atherosclerosis) decreases blood flow and, therefore, the oxygen supply to your heart, brain, and other parts of your body. Lowering your blood level of cholesterol and fats with pravastatin has been shown to prevent heart disease, angina (chest pain), strokes, and heart attacks.
Efavirenz Overview
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Efavirenz is used along with other medications to treat human immunodeficiency virus (HIV) infection. Efavirenz is in a class of medications called non-nucleoside reverse transcriptase inhibitors (NNRTIs). It works by decreasing the amount of HIV in the blood. Although efavirenz 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 (spreading) the HIV virus to other people.
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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.