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Drug Interactions between Afinitor Disperz and efavirenz

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

efavirenz everolimus

Applies to: efavirenz and Afinitor Disperz (everolimus)

MONITOR: Coadministration with inducers of CYP450 3A4 and/or P-glycoprotein (P-gp) may decrease the blood concentrations and pharmacologic effects of everolimus. In a study of healthy volunteers, multiple doses of the potent inducer rifampin increased the oral clearance of everolimus by threefold, representing mean decreases in peak blood concentration (Cmax) and systemic exposure (AUC) of 58% and 63%, respectively. The extent to which other inducers of CYP450 3A4 interact with everolimus is unknown.

MANAGEMENT: Some manufacturers recommend avoiding concomitant use of everolimus with moderate CYP450 3A4 and/or P-gp inducers such as bosentan, efavirenz, and nevirapine. If concomitant use is required, a dose adjustment of everolimus should be considered to achieve the recommended therapeutic range for the condition being treated. Please refer to the manufacturer's labeling for specific dosing information. Everolimus whole blood trough levels should be closely monitored during treatment, particularly 2 weeks after a dose increase and 2 weeks after discontinuation of the inducer.

References (3)
  1. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  2. Cerner Multum, Inc. "Australian Product Information."
  3. (2009) "Product Information. Afinitor (everolimus)." Novartis Pharmaceuticals

Drug and food interactions

Moderate

efavirenz food

Applies to: efavirenz

ADJUST DOSING INTERVAL: Administration with food increases the plasma concentrations of efavirenz and may increase the frequency of adverse reactions. According to the product labeling, administration of efavirenz capsules (600 mg single dose) with a high-fat/high-caloric meal (894 kcal, 54 g fat, 54% calories from fat) or a reduced-fat/normal-caloric meal (440 kcal, 2 g fat, 4% calories from fat) was associated with mean increases of 39% and 51% in efavirenz peak plasma concentration (Cmax) and 22% and 17% in systemic exposure (AUC), respectively, compared to administration under fasted conditions. For efavirenz tablets, administration of a single 600 mg dose with a high-fat/high-caloric meal (approximately 1000 kcal, 500-600 kcal from fat) resulted in a 79% increase in mean Cmax and a 28% increase in mean AUC of efavirenz relative to administration under fasted conditions.

GENERALLY AVOID: Alcohol may potentiate the central nervous system (CNS) depressant effects of efavirenz. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

MANAGEMENT: Efavirenz should be taken on an empty stomach, preferably at bedtime. Dosing at bedtime may improve the tolerability of nervous system symptoms such as dizziness, insomnia, impaired concentration, somnolence, abnormal dreams and hallucinations, although they often resolve on their own after the first 2 to 4 weeks of therapy . Patients should be advised of the potential for additive central nervous system effects when efavirenz is used concomitantly with alcohol or psychoactive drugs, and to avoid driving or operating hazardous machinery until they know how the medication affects them.

References (4)
  1. (2001) "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals
  2. (2023) "Product Information. Sustiva (efavirenz)." Bristol-Myers Squibb, SUPPL-59/47
  3. (2024) "Product Information. Stocrin (efavirenz)." Merck Sharp & Dohme (Australia) Pty Ltd
  4. (2024) "Product Information. Efavirenz (efavirenz)." Viatris UK Healthcare Ltd
Moderate

everolimus food

Applies to: Afinitor Disperz (everolimus)

GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered everolimus. The mechanism is inhibition of CYP450 3A4 and P-glycoprotein activity in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients treated with everolimus should avoid consumption of grapefruit and grapefruit juice.

References (1)
  1. (2009) "Product Information. Afinitor (everolimus)." Novartis Pharmaceuticals

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.


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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.