Efavirenz Aurobindo (Efavirenz 600 mg)

What Is Efavirenz Aurobindo and What Is It Used For?

Quick Answer: Efavirenz Aurobindo is an antiretroviral medicine containing efavirenz, a non-nucleoside reverse transcriptase inhibitor (NNRTI) used to treat HIV-1 infection. It is taken once daily in combination with other antiretroviral drugs to suppress viral replication, strengthen the immune system, and prevent HIV-related illness.

Efavirenz, the active substance in Efavirenz Aurobindo, belongs to a class of antiretroviral medicines called non-nucleoside reverse transcriptase inhibitors (NNRTIs). These drugs target a specific enzyme — reverse transcriptase — that HIV-1 requires to convert its genetic material (RNA) into DNA, a crucial early step in the viral replication cycle. By binding directly to reverse transcriptase in a non-competitive manner, efavirenz induces a conformational change that renders the enzyme non-functional, effectively blocking the production of new viral particles.

Efavirenz was first approved by the United States Food and Drug Administration (FDA) in 1998 and has since become one of the most widely prescribed antiretroviral agents worldwide. It is included on the World Health Organization (WHO) Model List of Essential Medicines, reflecting its global importance in HIV management. The WHO Consolidated Guidelines on HIV (2024) continue to recognize efavirenz-based regimens as an alternative first-line option for adults and adolescents, particularly in settings where preferred agents such as dolutegravir are not available or are contraindicated.

In clinical practice, efavirenz is always prescribed as part of combination antiretroviral therapy (cART), typically combined with two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) such as tenofovir and emtricitabin, or abacavir and lamivudine. This combination approach attacks the virus at multiple stages of its life cycle, maximizing viral suppression and minimizing the risk of drug resistance. Landmark clinical trials, including ACTG 5142 and Study 934, demonstrated that efavirenz-based regimens achieve high rates of sustained virologic suppression (HIV RNA below 50 copies/mL) in treatment-naive patients.

The goal of treatment with efavirenz-containing regimens is to reduce the viral load to undetectable levels, thereby restoring and preserving immune function (as measured by CD4+ T-cell count), preventing the progression to acquired immunodeficiency syndrome (AIDS), reducing the risk of opportunistic infections, and decreasing the probability of onward HIV transmission. It is important to understand that efavirenz is not a cure for HIV — the virus persists in latent reservoirs even when the viral load is undetectable. Lifelong adherence to antiretroviral therapy remains essential.

Efavirenz Aurobindo is a generic formulation manufactured by Aurobindo Pharma, containing the same active substance and bioequivalent to the originator product. Generic antiretrovirals have been instrumental in expanding global access to HIV treatment, particularly in low- and middle-income countries where the burden of HIV is greatest. The European Medicines Agency (EMA) requires generic products to demonstrate pharmaceutical equivalence and bioequivalence to the reference medicine before granting marketing authorization.

What Should You Know Before Taking Efavirenz Aurobindo?

Quick Answer: Do not take efavirenz if you have severe liver disease, certain heart rhythm disorders, or are allergic to efavirenz. It must not be combined with several specific medications including midazolam, ergot alkaloids, St John’s Wort, and elbasvir/grazoprevir. Inform your doctor about all medical conditions and medications before starting treatment.

Contraindications

Efavirenz Aurobindo must not be used in the following circumstances. If any of these apply to you, inform your doctor immediately before starting treatment:

• Hypersensitivity: Known allergy to efavirenz or any of the excipients in the tablet formulation. If you have previously experienced an allergic reaction to efavirenz — such as severe skin rash, facial swelling, or breathing difficulties — you must not take this medicine again.
• Severe liver disease: Patients with severely impaired liver function must not take efavirenz due to the risk of further hepatotoxicity and altered drug metabolism.
• Heart rhythm disorders: Efavirenz is contraindicated in patients with changes in heart rhythm or rate (including prolonged QT interval), slow heartbeat (bradycardia), or severe heart disease. It is also contraindicated if a family member (parent, grandparent, or sibling) has died suddenly from a cardiac problem or was born with heart disease.
• Electrolyte abnormalities: Patients with high or low levels of potassium or magnesium in the blood must not take efavirenz until these imbalances have been corrected.

Warnings and Precautions

Several important precautions must be observed before and during treatment with efavirenz. Discuss the following with your doctor:

• Psychiatric history: If you have a history of mental illness, depression, or substance abuse (alcohol or drugs), inform your doctor before starting efavirenz. Central nervous system effects including depression, suicidal ideation, and unusual thoughts have been reported. Some patients have committed suicide. These problems tend to occur more frequently in patients with pre-existing psychiatric conditions. Tell your doctor immediately if you experience depression, suicidal thoughts, or strange thoughts during treatment.
• Seizures: If you have a history of seizures (fits, convulsions) or are being treated with anticonvulsant medications such as carbamazepine, phenobarbital, or phenytoin, inform your doctor. Efavirenz may affect the blood levels of these medications, requiring dose adjustments or alternative anticonvulsant therapy.
• Liver disease: If you have a history of liver disease, including chronic active hepatitis B or C, there is an increased risk of serious and potentially life-threatening hepatic adverse events. Your doctor will perform regular blood tests to monitor liver function and may need to switch you to a different treatment. Patients with severe liver disease must not take efavirenz.
• Heart conditions: If you have any form of heart disease, particularly an abnormal electrical signal known as prolonged QT interval, inform your doctor as efavirenz may exacerbate cardiac conduction abnormalities.

When you first start taking efavirenz, watch for the following:

• Central nervous system symptoms: Dizziness, sleep disturbances, drowsiness, impaired concentration, and abnormal dreams may occur during the first 1–2 days and usually resolve within 2–4 weeks. Taking efavirenz at bedtime on an empty stomach can help minimize these effects.
• Skin rash: If you develop a rash, most cases are mild and resolve without stopping treatment. However, if you experience severe rash with blistering or fever, stop taking efavirenz and contact your doctor immediately. If you have previously had a rash with another NNRTI, you may be at greater risk of developing a rash with efavirenz.
• Bone problems: Some patients receiving combination antiretroviral therapy may develop osteonecrosis (death of bone tissue due to loss of blood supply). Risk factors include prolonged antiretroviral therapy, corticosteroid use, alcohol consumption, severe immunosuppression, and higher body mass index. Symptoms include joint stiffness, pain (especially in the hip, knee, and shoulder), and difficulty moving. Report these symptoms to your doctor.

Pregnancy and Breastfeeding

Women should not become pregnant during treatment with efavirenz and for 12 weeks after stopping treatment. Your doctor may require a pregnancy test before initiating therapy to confirm that you are not pregnant. If you are at risk of becoming pregnant, you must use reliable barrier contraception (such as condoms) in addition to other contraceptive methods, including hormonal contraceptives (pills, injections, implants), because efavirenz may reduce the effectiveness of hormonal contraception.

Serious birth defects have been observed in the offspring of animals treated with efavirenz, and a small number of cases have been reported in human infants born to mothers who received efavirenz-containing regimens during pregnancy. If you are pregnant, efavirenz should only be taken if you and your doctor determine that there is a clear clinical need. Current international guidelines (BHIVA 2024, EACS 2024) generally recommend alternative antiretroviral agents for women who are pregnant or planning pregnancy.

You should not breastfeed while taking efavirenz. Breastfeeding is not recommended for women living with HIV because HIV can be transmitted to the child through breast milk. If you are breastfeeding or considering breastfeeding, discuss this with your doctor as soon as possible.

Driving and Operating Machinery

Efavirenz may cause dizziness, impaired concentration, and drowsiness. If you are affected by these symptoms, do not drive or operate machinery. These effects are most pronounced during the first weeks of treatment and typically diminish as your body adjusts to the medication. You are responsible for assessing your fitness to drive or perform tasks requiring alertness.

Important Information About Excipients

Efavirenz Aurobindo contains lactose monohydrate. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine. This medicine contains less than 1 mmol (23 mg) sodium per tablet — it is essentially sodium-free.

How Does Efavirenz Aurobindo Interact with Other Drugs?

Quick Answer: Efavirenz has numerous clinically significant drug interactions. It is a potent inducer of CYP3A4 and CYP2B6 liver enzymes, which can decrease the blood levels and effectiveness of many co-administered medications. Several drugs are strictly contraindicated with efavirenz, and many others require dose adjustments. Always inform your doctor about all medications, including herbal products.

Efavirenz is a mixed inducer and inhibitor of the cytochrome P450 enzyme system, with its primary effect being induction of CYP3A4 and CYP2B6. This means it can accelerate the metabolism of many other drugs, reducing their plasma concentrations and potentially their therapeutic efficacy. Conversely, some drugs can alter efavirenz levels, either increasing the risk of toxicity or reducing its antiviral activity. The extensive interaction profile of efavirenz makes thorough medication review essential before starting and during treatment.

Major Interactions (Contraindicated or High Risk)

Clinically Significant Interactions Requiring Dose Adjustment

The interactions listed above are not exhaustive. Efavirenz can also affect the levels of calcium channel blockers (such as diltiazem), bupropion, antimalarials (artemether/lumefantrine, atovaquone/proguanil), the antiparasitic praziquantel, and Ginkgo biloba extract. It is essential to inform your doctor, pharmacist, or nurse about all medicines you are currently taking, have recently taken, or might take, including over-the-counter products and herbal supplements.

What Is the Correct Dosage of Efavirenz Aurobindo?

Quick Answer: The recommended dose for adults is 600 mg (one film-coated tablet) once daily, taken on an empty stomach, preferably at bedtime. The tablet should be swallowed whole with water. Efavirenz must always be taken in combination with other antiretroviral medicines.

Always take efavirenz exactly as your doctor or pharmacist has instructed. Do not change the dose, skip doses, or stop taking the medication without consulting your healthcare provider. Consistent adherence to the prescribed regimen is critical for maintaining virologic suppression and preventing the emergence of drug-resistant HIV strains.

Adults

If you are also taking certain other medications, your doctor may need to increase or decrease the dose of efavirenz (see the Drug Interactions section above). For example, when co-administered with rifampicin, an increase to 800 mg daily may be considered in patients weighing over 60 kg.

Children and Adolescents

The 600 mg film-coated tablet is suitable for children and adolescents weighing 40 kg or more, at the same dose as adults (600 mg once daily). For children weighing less than 40 kg, this tablet formulation is not appropriate; alternative formulations with weight-based dosing (such as oral solution or lower-strength tablets) should be used as prescribed by the treating physician.

Efavirenz is approved for use in children aged 3 months and older weighing at least 3.5 kg, although it has not been sufficiently studied in children younger than 3 months or weighing less than 3.5 kg. Pediatric dosing must always be determined by a physician experienced in the management of HIV in children.

Elderly Patients

There is limited clinical experience with efavirenz in patients over the age of 65. No specific dose adjustment is established for elderly patients. However, older patients are more likely to have coexisting medical conditions and to be taking multiple medications, increasing the potential for drug interactions and adverse effects. Close monitoring is recommended.

Missed Dose

If you forget to take a dose, take the next dose as soon as possible, but do not take a double dose to compensate for the missed one. Maintaining a consistent daily schedule is important for optimal viral suppression. If you need help planning when to take your medication, consult your doctor or pharmacist. Setting a daily reminder or using a pill organizer may be helpful.

Overdose

What Are the Side Effects of Efavirenz Aurobindo?

Quick Answer: The most prominent side effects are skin rash (very common) and central nervous system symptoms including dizziness, abnormal dreams, insomnia, drowsiness, and impaired concentration (common). CNS symptoms usually appear in the first 1–2 days and resolve within 2–4 weeks. Serious but rare effects include liver failure, severe skin reactions, and psychiatric symptoms.

Like all medicines, efavirenz can cause side effects, although not everybody gets them. During HIV treatment, it is not always possible to determine whether certain unwanted effects are caused by efavirenz, by other medicines taken concurrently, or by the HIV infection itself. Weight gain and increased levels of lipids and glucose in the blood may also occur during HIV treatment, partly related to restored health and lifestyle, though blood lipid changes may sometimes be linked to the antiretroviral medicines themselves.

Central Nervous System Effects

The central nervous system (CNS) side effects of efavirenz are among its most distinctive characteristics and are a primary reason the medication is taken at bedtime. These symptoms — which include dizziness, insomnia, vivid or disturbing dreams, impaired concentration, and drowsiness — typically appear within the first 1–3 hours after a dose and are most noticeable during the first days of treatment. In clinical studies, CNS symptoms generally subsided within the first 2–4 weeks of continued therapy, although a minority of patients may experience persistent effects that require switching to an alternative antiretroviral regimen.

Taking efavirenz on an empty stomach at bedtime is the primary strategy for mitigating CNS effects. A high-fat meal can increase efavirenz absorption by up to 50%, which may intensify side effects. If CNS symptoms significantly affect your quality of life or do not improve after the initial weeks, discuss alternative treatment options with your doctor.

Skin Rash

Skin rash is the most commonly reported side effect of efavirenz, affecting more than 1 in 10 patients. In most cases, the rash is mild to moderate (maculopapular) and resolves spontaneously within 2–4 weeks without requiring discontinuation of treatment. However, severe rash — including Stevens-Johnson syndrome and erythema multiforme — has been reported in uncommon cases. Rash is more common in children than in adults receiving efavirenz. If you experience any rash, contact your doctor for assessment. Discontinue efavirenz immediately and seek medical attention if the rash is accompanied by blistering, peeling, fever, or mucosal involvement.

Psychiatric Effects

Efavirenz has been associated with a spectrum of psychiatric adverse effects beyond the common CNS symptoms described above. These include severe depression, suicidal ideation and attempts, aggressive behavior, paranoid thinking, and hallucinations. In rare cases, patients have committed suicide during efavirenz treatment. Patients with a pre-existing history of psychiatric disorders are at higher risk. The British HIV Association (BHIVA 2024) and other guideline bodies recommend careful psychiatric assessment before prescribing efavirenz and vigilant monitoring during treatment, particularly in the first months.

Reporting Side Effects

If you experience any side effects, including any not listed above, talk to your doctor or pharmacist. You can also report suspected adverse reactions to your national pharmacovigilance authority. Reporting helps provide more information on the safety profile of this medicine and benefits all patients.

How Should You Store Efavirenz Aurobindo?

Quick Answer: Store at room temperature with no special storage conditions required. Keep out of the sight and reach of children. Do not use after the expiry date printed on the packaging.

Proper storage of efavirenz is important to maintain the medication's quality and effectiveness throughout its shelf life. The following storage guidelines apply:

• Temperature: No special temperature storage requirements. Store at normal room temperature.
• Children: Keep this medicine out of the sight and reach of children at all times.
• Expiry date: Do not use after the expiry date stated on the label and carton. The expiry date refers to the last day of that month.
• Packaging: Efavirenz Aurobindo 600 mg film-coated tablets are available in clear PVC/PVdC-aluminium blister packs (30 or 90 tablets) and white opaque HDPE bottles with polypropylene caps (30, 90, or 500 tablets). Not all pack sizes may be marketed.

Do not dispose of medications via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. Proper disposal helps protect the environment and prevents accidental ingestion by others.

What Does Efavirenz Aurobindo Contain?

Quick Answer: Each film-coated tablet contains 600 mg of the active ingredient efavirenz. The tablet is yellow, oval, biconvex with beveled edges, debossed with “L” on one side and “11” on the other. Size: 20.1 mm × 9.6 mm.

Understanding the full composition of your medication is important, particularly if you have known allergies or intolerances to specific ingredients.

Active Substance

The active pharmaceutical ingredient is efavirenz, present at a dose of 600 mg per film-coated tablet. Efavirenz (chemical name: (S)-6-chloro-4-(cyclopropylethynyl)-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one) is a non-nucleoside inhibitor of HIV-1 reverse transcriptase.

Inactive Ingredients (Excipients)

The excipients serve various pharmaceutical functions including tablet formation, stability, and coating:

Tablet core:

• Microcrystalline cellulose (grade 101 and 200) (E460) — filler and binder
• Low-substituted hydroxypropylcellulose (LH-21) — disintegrant
• Lactose monohydrate — filler (relevant for patients with lactose intolerance)
• Hydroxypropylcellulose (low viscosity grade) — binder
• Colloidal anhydrous silica — flow agent
• Crospovidone (type A and B) — disintegrant
• Sodium lauryl sulfate — wetting agent
• Magnesium stearate — lubricant

Film coating:

• Hypromellose type 2910 (E464) — coating agent
• Macrogol — plasticizer
• Titanium dioxide (E171) — opacifier
• Yellow iron oxide (E172) — colorant

Tablet Appearance

Efavirenz Aurobindo 600 mg is a yellow, oval, biconvex film-coated tablet with beveled edges. It is debossed with “L” on one side and “11” on the other. Tablet dimensions are 20.1 mm × 9.6 mm. The tablet should be swallowed whole — do not crush, break, or chew.