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-established efficacy profile makes it a preferred 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 weighing ≥3.5 kg
• Requires combination therapy with other antiretroviral agents

Benefits

• Achieves rapid and sustained viral load suppression to undetectable levels
• Supports immune reconstitution through consistent CD4+ cell count improvement
• Reduces risk of HIV-related complications and disease progression
• Once-daily dosing enhances regimen adherence and quality of life
• Well-studied long-term efficacy and safety profile in diverse populations
• Available in fixed-dose combinations for simplified treatment schedules

Common use

Sustiva is indicated as part of combination antiretroviral therapy for the treatment of HIV-1 infection. It is commonly prescribed for treatment-naïve patients and may be used in certain treatment-experienced individuals without documented resistance to efavirenz. Clinical guidelines frequently recommend efavirenz-based regimens as first-line options due to their potent antiviral activity, high genetic barrier to resistance (when used appropriately), and extensive clinical experience. It is often combined with nucleoside reverse transcriptase inhibitors such as tenofovir/emtricitabine.

Dosage and direction

The recommended adult dosage is 600 mg orally once daily. For pediatric patients, dosing is weight-based:

• 3.5 kg to <5 kg: 100 mg daily
• 5 kg to <7.5 kg: 150 mg daily
• 7.5 kg to <15 kg: 200 mg daily
• 15 kg to <20 kg: 250 mg daily
• 20 kg to <25 kg: 300 mg daily
• 25 kg to <32.5 kg: 350 mg daily
• 32.5 kg to <40 kg: 400 mg daily
• ≥40 kg: 600 mg daily

Administration should occur on an empty stomach, preferably at bedtime, to minimize central nervous system effects. Tablets should be swallowed whole with water. Do not crush, chew, or break tablets.

Precautions

Neuropsychiatric symptoms including severe depression, suicidal ideation, psychosis, and aggressive behavior have been reported. Monitor patients, especially those with pre-existing psychiatric conditions. Rash occurs commonly, usually within the first two weeks of therapy; severe cases including Stevens-Johnson syndrome have occurred. Hepatic transaminases may elevate; monitor liver function before and during treatment. Use caution in patients with hepatitis B or C coinfection. May cause fetal harm; pregnancy should be avoided. Lipid elevations may occur; monitor serum cholesterol and triglycerides. May cause dizziness, impaired concentration, and somnolence; caution patients about operating machinery or driving.

Contraindications

Hypersensitivity to efavirenz or any component of the formulation. Coadministration with elbasvir/grazoprevir, voriconazole, cisapride, midazolam, pimozide, triazolam, or ergot derivatives due to potential for serious and/or life-threatening reactions. Concomitant use with drugs that are highly dependent on CYP3A4 for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events.

Possible side effects

Most common adverse reactions (≥10%): rash, dizziness, nausea, headache, fatigue, insomnia, abnormal dreams, impaired concentration. Serious adverse reactions: severe skin reactions, hepatotoxicity, psychiatric symptoms, convulsions, immune reconstitution syndrome. Laboratory abnormalities: elevated ALT/AST, elevated amylase, elevated triglycerides, elevated cholesterol, neutropenia.

Drug interaction

Potent CYP3A4 inducer; may decrease concentrations of many drugs including: certain antifungals (voriconazole, posaconazole), anticoagulants (warfarin), anticonvulsants (carbamazepine), antidepressants, antimycobacterials (rifabutin), calcium channel blockers, corticosteroids, immunosuppressants, hormonal contraceptives, methadone, sedatives/hypnotics, and simvastatin. Contraindicated with drugs that inhibit CYP3A4 and increase efavirenz levels. Coadministration with other NNRTIs not recommended. St. John’s wort may decrease efavirenz concentrations.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double the next dose. Maintain regular dosing schedule to ensure consistent antiviral activity.

Overdose

Experience is limited. 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 observation of clinical status. Since efavirenz is highly protein-bound, dialysis is unlikely to remove significant quantities.

Storage

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Keep bottle tightly closed and protect from moisture. Keep out of reach of children.

Disclaimer

This information is for educational purposes and does not constitute medical advice. Treatment decisions must be made by qualified healthcare professionals based on individual patient characteristics. Always follow prescribing information and clinical guidelines. Not all possible uses, interactions, or adverse effects are listed here.

Reviews

Clinical trials demonstrate sustained virologic response rates of 60-70% at 48 weeks in treatment-naïve patients when combined with appropriate background regimen. Real-world evidence supports long-term durability with maintained viral suppression in adherent patients. Neuropsychiatric side effects remain a treatment consideration, though often diminish after initial weeks. Resistance development occurs primarily through K103N mutation; baseline resistance testing is recommended. Overall, remains a valuable component of antiretroviral therapy when appropriately selected and monitored.