Sustiva (efavirenz) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) indicated for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in combination with other antiretroviral agents. As a cornerstone of many highly active antiretroviral therapy (HAART) regimens, it offers potent viral suppression, contributing to improved immunologic function and long-term disease control. Its once-daily dosing supports adherence, a critical factor in treatment success, while its well-characterized safety profile makes it a trusted option in both treatment-naïve and experienced patients under appropriate clinical guidance.

Features

• Active ingredient: Efavirenz 600 mg
• Pharmacologic class: Non-nucleoside reverse transcriptase inhibitor (NNRTI)
• Formulation: Film-coated tablets for oral administration
• Dosing frequency: Once daily, preferably at bedtime
• FDA-approved for use in adults and pediatric patients ≥3 months old and weighing ≥3.5 kg
• Requires combination therapy with other antiretroviral agents

Benefits

• Achieves rapid and sustained reduction in viral load through potent inhibition of HIV-1 reverse transcriptase
• Supports immune reconstitution by maintaining virologic suppression, leading to increased CD4+ cell counts
• Once-daily dosing enhances treatment adherence and simplifies complex regimens
• Proven long-term efficacy in clinical trials with durable response rates
• Available in fixed-dose combinations for further regimen simplification
• Suitable for a broad patient population, including pediatric patients ≥3 months

Common use

Sustiva is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. It is commonly prescribed as part of initial therapy regimens for treatment-naïve patients and may be used in certain treatment-experienced patients without documented resistance to efavirenz. Clinical guidelines recommend its use based on individual patient factors, including viral load, CD4 count, comorbid conditions, and potential drug interactions. It is particularly valued in regimens where once-daily dosing is preferred to support long-term adherence.

Dosage and direction

Adults: The recommended dosage is 600 mg orally once daily.
Pediatric patients: Dosage is based on body weight and must be calculated precisely according to prescribing guidelines.
Administration: Should be taken on an empty stomach, preferably at bedtime, to minimize central nervous system side effects. Tablets should be swallowed whole with water. For patients unable to swallow tablets, alternative formulations or compounding may be considered under medical supervision. Dosage adjustments are required when coadministered with certain medications that affect CYP450 metabolism.

Precautions

• Psychiatric symptoms: Monitor for severe depression, suicidal ideation, or psychosis, particularly in patients with pre-existing psychiatric conditions
• Nervous system symptoms: Dizziness, insomnia, impaired concentration, and abnormal dreams are common initially; patients should avoid hazardous activities if affected
• Hepatotoxicity: Monitor liver function tests before and during treatment; use with caution in patients with hepatic impairment
• Lipid effects: May increase total cholesterol and triglycerides; monitor lipid profile periodically
• Pregnancy: Not recommended during the first trimester due to potential fetal harm; pregnancy testing recommended before initiation
• Rash: Usually mild to moderate and self-limiting; discontinuation may be necessary for severe cases

Contraindications

• Hypersensitivity to efavirenz or any component of the formulation
• Coadministration with elbasvir/grazoprevir, voriconazole, or pimozide due to potentially serious interactions
• Patients with severe hepatic impairment (Child-Pugh Class C) without careful benefit-risk assessment
• Use with drugs that are highly dependent on CYP3A4 for clearance and have narrow therapeutic indices

Possible side effects

Very common (>10%):

• Dizziness
• Insomnia
• Abnormal dreams
• Headache
• Rash
• Fatigue

Common (1-10%):

• Nausea
• Diarrhea
• Increased cholesterol and triglycerides
• Depression
• Anxiety
• Impaired concentration

Uncommon (<1%):

• Severe skin reactions
• Hepatotoxicity
• Suicidal ideation
• Convulsions
• Gynecomastia

Drug interaction

Sustiva is a moderate inducer of CYP3A4 and may affect drugs metabolized by this pathway. Significant interactions include:

• Anticonvulsants: Carbamazepine, phenobarbital may decrease efavirenz concentrations
• Antifungals: Voriconazole contraindicated; reduced itraconazole, posaconazole concentrations
• Protease inhibitors: May alter concentrations of both agents; dosage adjustments often needed
• Macrolides: Clarithromycin concentrations decreased
• Methadone: May decrease methadone levels; monitor for opioid withdrawal
• Oral contraceptives: Alternative contraception recommended
• Warfarin: Monitor INR closely

Missed dose

If a dose is missed, it should be taken as soon as possible unless it is nearly time for the next dose. Do not double the next dose. Maintaining regular dosing schedule is crucial to prevent development of resistance. If vomiting occurs within hours of dosing, consult healthcare provider regarding whether to repeat the dose.

Overdose

Limited experience with overdose. Symptoms may include increased nervous system symptoms. There is no specific antidote; treatment should consist of general supportive measures including monitoring of vital signs and ECG. Charcoal may be administered if presented soon after ingestion. Hemodialysis is unlikely to be effective due to high protein binding.

Storage

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Keep in original container with tightly closed lid to protect from moisture. Keep out of reach of children and pets. Do not use after expiration date printed on packaging.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Treatment decisions must be made by qualified healthcare providers based on individual patient circumstances. Full prescribing information including boxed warnings should be reviewed before initiation. Patients should report any adverse effects to their healthcare provider promptly.

Reviews

“Sustiva has been a mainstay in my HIV practice for over two decades. Its once-daily dosing and consistent efficacy make it valuable, though we carefully select patients due to CNS side effects.” – Infectious Disease Specialist, 15 years experience

“In combination therapy, we’ve seen excellent virologic response rates. The key is proper patient education about taking it at bedtime and managing initial side effects.” – HIV Clinical Pharmacist

“While newer agents exist, efavirenz remains relevant in resource-limited settings and for specific patient profiles where its long-term data and affordability are advantageous.” – Global Health Physician