Efavirenz Dosage

Medically reviewed by Drugs.com. Last updated on Nov 26, 2019.

Usual Adult Dose for HIV Infection

600 mg orally once a day

Comments:
-This drug should be used with a protease inhibitor and/or NRTIs.

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Usual Adult Dose for Nonoccupational Exposure

US CDC recommendations: 600 mg orally once a day
Duration of therapy: 28 days

Comments:
-This drug should be used with (lamivudine or emtricitabine) plus (zidovudine or tenofovir); recommended as the preferred NNRTI-based regimen for nonoccupational postexposure prophylaxis of HIV infection.
-Prophylaxis should be started as soon as possible, within 72 hours of exposure.
-Not approved by US FDA.

Usual Adult Dose for Occupational Exposure

US Public Health Service working group recommendations: 600 mg orally once a day
Duration of therapy: 28 days, if tolerated

Comments:
-An alternative antiretroviral agent for use as HIV postexposure prophylaxis only with expert consultation
-Prophylaxis should be started as soon as possible, preferably within hours after exposure.
-The optimal duration of prophylaxis is unknown and may differ based on institution protocol.
-The most current therapeutic guidelines should be consulted for more information.
-Not approved by US FDA.

Usual Pediatric Dose for HIV Infection

3 months or older:
3.5 to less than 5 kg: 100 mg orally once a day
5 to less than 7.5 kg: 150 mg orally once a day
7.5 to less than 15 kg: 200 mg orally once a day
15 to less than 20 kg: 250 mg orally once a day
20 to less than 25 kg: 300 mg orally once a day
25 to less than 32.5 kg: 350 mg orally once a day
32.5 to less than 40 kg: 400 mg orally once a day
40 kg or more: 600 mg orally once a day

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

Mild liver dysfunction: No adjustment recommended; caution recommended.
Moderate to severe liver dysfunction: Not recommended.

Dose Adjustments

Adults:
-If used with voriconazole: Decrease efavirenz dose to 300 mg orally once a day using the capsule formulation; the manufacturer product information should be consulted.
-If used with rifampin in patients weighing 50 kg or more: Increase efavirenz dose to 800 mg orally once a day.

Precautions

Safety and efficacy have not been established in patients younger than 3 months or less than 3.5 kg; this drug is not recommended for use in these patients.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Comments: This drug is highly protein-bound; significant removal via dialysis is not likely.

Other Comments

Administration advice:
-Administer on an empty stomach (bedtime preferable); administration with food increases drug levels and may increase rate of side effects.
-Administer at bedtime to improve tolerability of CNS side effects.
-Do not crush tablets; swallow tablets intact with liquid.
-Capsules can be swallowed intact with liquid or administered using the sprinkle method.
-For patients unable to swallow capsules or tablets, the capsule contents can be administered with a small amount (1 to 2 teaspoons) of food; consult the manufacturer product information regarding administration using the sprinkle method.
-Consult the manufacturer product information regarding missed doses.

Reconstitution/preparation techniques:
-The manufacturer product information should be consulted regarding preparation for the capsule sprinkle method of administration.

General:
-This drug should always be used in combination with other antiretroviral agents; it should not be used as a single agent to treat HIV-1.
-This drug should not be added on as a sole agent to a failing regimen.

Monitoring:
-General: Pregnancy testing (before starting this drug)
-Hepatic: Liver enzymes (before and during therapy)
-Metabolic: Triglycerides and cholesterol (before and periodically during therapy)

Patient advice:
-This drug may impair mental abilities needed to perform potentially hazardous tasks (e.g., driving, operating machinery); CNS effects may be additive if used with alcohol or psychoactive drugs. Avoid hazardous tasks if CNS symptoms (e.g., dizziness, impaired concentration, drowsiness) occur.

Frequently asked questions

• What is the difference between HIV treatments Symfi and Symfi Lo?
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Further information

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

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