Efavirenz Dosage

Medically reviewed by Drugs.com. Last updated on Nov 16, 2021.

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?
• What drugs are contained in the HIV treatment Symfi Lo?

Further information

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

Medical Disclaimer