Efavir 600mg (Efavirenz) for HIV Treatment

Efavir 600mg belongs to a class of drugs called reverse transcriptase inhibitors, which also includes Zalcitabine, Zidovudine, didanosine, and lamivudine. It belongs to a subclass of reverse transcriptase inhibitors, referred to as non-nucleoside reverse transcriptase inhibitors that include nevirapine and delavirdine. It is always taken in combination with other HIV drugs, to treat infections with Human deficiency (HIV). The name of the medicine is Efavir, and it contains Efavirenz as an active ingredient. The drug is safe and effective in children younger than three months and who weigh less than 3.5 kg.

What is Efavir 600mg (Efavirenz) used for?

Efavir 600mg (Efavirenz) is a prescription Human Immunodeficiency Virus type 1 (HIV-1) drug, used to treat in adults and in children, who are at least three months old and weigh at least 3.5 kg. Human Immunodeficiency virus is a virus that causes Acquired Immunodeficiency Syndrome or AIDS. The medicine stops HIV from multiplying but does not cure the disease.

Precautions

Tell the doctor before consuming Efavir:

If you are hypersensitive to the drug, or its components
If you are taking alcohol beverages
If you are going for surgery, or a dental surgery
If you have or ever had depression, seizures, high cholesterol, or other mental problems, or liver, pancreas or heart disease
The drug may cause dizziness. Do not drive or use machinery, while taking Efavirenz as these activities may require a high degree of mental attention
If you are pregnant or intending to become pregnant. You should discuss the benefits and risks of taking Efavir capsules during pregnancy. Breastfeeding women are advised not to take Efavirenz as it may pass into breast milk and harm the nursing baby
Do not consume alcohol while using Efavirenz, as with all antihistamine drugs
The medicine is not intended to use in children aged under two years

General

Do not forget to see the expiry date of the product.
Keep the drug reach out of children.
It should not be given to anybody, even if they have the same problems.
Always keep the written record of your medications.

What medications interact with Efavir 600 mg?

The following medicines should be avoided, in case doctor recommends you Efavirenz to avoid possible drug interactions.

Methylergonovine
Midazolam
Pimozide
Ergotamine
Dihydroergotamine
Cisapride
Triazolam
Pimozide

Dosage Instructions

Side Effects

What are the side effects of Efavir 600 mg?

Like other medicines, Efavir 600 mg may cause adverse effects. Seek medical attention, in case the following troubles arise:

Concentration troubles
Vomiting
Nausea
Unusual dreams
Dizziness
Trouble sleeping
Headache
Diarrhea

Some adverse effects of Efavir 600 mg can be serious. Visit the doctor immediately, in the following situations.

Severe depression
Suicidal thoughts
Aggression
Severe depression
Extreme fear
Hallucinations

How to Use

How should Efavir 600 mg be taken?

Efavir 600 mg comes in the form of capsule. Swallow the capsule with a glass of water.
To treat adults and adolescents who weigh 40 kg or more: The recommended dose of Efavirenz is one 600 mg capsule every day, ideally at bedtime. Taking the drug at bedtime reduces the risk of having side effects.
Take the capsule when you are empty stomach, or take it with low-calorie food.
To treat patients who weigh less than 40 kg: An oral solution or capsule containing a small amount of Efavirenz can be used.
Take the tablet exactly as prescribed by the doctor. Do not alter the dosage plan.
Overdose: Seek medical attention immediately, in the case of an overdose of Efavirenz.

Missed dose of Efavir 600 mg

If you have forgotten a dose, take it as soon you remember and go back to your usual dosing schedule. If the time to take the next dose is near, leave the forgotten dose and take the next dose. Do not double up the dose to compensate the missed one.

Take the capsule for as long as your doctor recommended.

Infographics

FAQ

What is Efavir 600mg used for?

Efavir 600mg contains efavirenz 600mg — the standard full adult dose of this NNRTI in a single tablet. It is used in combination antiretroviral therapy for HIV-1 infection, typically combined with tenofovir DF and emtricitabine or lamivudine. The once-daily 600mg tablet is more convenient than three 200mg tablets and is the preferred efavirenz formulation for adult HIV treatment. It is also the efavirenz dose in the widely used fixed-dose combination Atripla (efavirenz 600mg/tenofovir DF 300mg/emtricitabine 200mg).

Why is efavirenz taken at night as a single 600mg dose?

The 600mg once-daily dose produces a high peak plasma concentration approximately 3–5 hours after ingestion — this peak is associated with peak CNS effects (dizziness, dissociation, vivid dreams). By taking the tablet at bedtime (10pm–midnight), patients experience peak CNS effects during sleep, largely avoiding daytime functional impairment. This simple timing strategy significantly improves tolerability and is strongly recommended in all guidelines. Morning dosing produces peak CNS effects during waking hours — impairing work, driving, and daily activities. Consistent bedtime administration is key to efavirenz tolerability.

What genetic factor affects efavirenz 600mg metabolism?

CYP2B6 *6 polymorphism significantly affects efavirenz pharmacokinetics. Approximately 20–30% of sub-Saharan African patients are CYP2B6 slow metabolisers — they achieve 3–4× higher efavirenz plasma levels than fast metabolisers. Slow metabolisers have higher rates of CNS side effects and more persistent CNS symptoms. Genotypic testing for CYP2B6 polymorphisms is not routine but explains variable efavirenz tolerability across populations. In known slow metabolisers, dose reduction to 400mg once daily has been studied and shown equivalent efficacy with better tolerability — an option under investigation in some programmes.

How should Efavir 600mg be taken for best results?

Take one Efavir 600mg tablet once daily at bedtime. Take on an empty stomach or with a light snack — avoid high-fat meals (increase absorption by 50%, worsening CNS toxicity). Swallow whole with water. Maintain consistent daily timing. Combined with tenofovir DF + emtricitabine/lamivudine, three separate tablets can be taken simultaneously at bedtime — or a single-tablet regimen (STR) such as Atripla offers the same three drugs in one tablet. Complete viral suppression requires excellent adherence — missed doses risk resistance with this low-barrier NNRTI.

Is Efavir 600mg safe in patients with liver disease?

Efavirenz is primarily metabolised by CYP2B6 and CYP3A4 in the liver. In mild hepatic impairment (Child-Pugh A), no dose adjustment is required but regular LFT monitoring is essential. In moderate impairment (Child-Pugh B), efavirenz should be used with caution — plasma levels may increase significantly. In severe hepatic impairment (Child-Pugh C), efavirenz is contraindicated. HIV/HCV co-infected patients on efavirenz-based therapy should have LFTs monitored every 3 months — hepatotoxicity, though less common than with nevirapine, does occur with efavirenz.

What monitoring is required during Efavir 600mg therapy?

Routine HIV monitoring: viral load every 3–6 months (target <50 copies/mL), CD4 count every 3–6 months, LFTs every 6 months, fasting lipids and glucose annually (efavirenz raises total cholesterol and LDL). CNS monitoring: formally assess CNS symptoms at each visit (weeks 2, 4, 8, then 3-monthly). Psychiatric monitoring: screen for depression and suicidal ideation. Contraception counselling: confirm effective non-hormonal contraception is in use for all women of childbearing potential. Resistance testing at baseline and if viral load >200 copies/mL on therapy.

How does Efavir 600mg perform long-term for HIV suppression?

Long-term clinical trial data (ACTG studies, ARTEMIS, ECHO/THRIVE) show efavirenz 600mg maintaining virological suppression in 60–80% of patients at 48–96 weeks in large trials. However, modern integrase inhibitors (dolutegravir, bictegravir) outperform efavirenz on both efficacy (higher % suppression) and tolerability (no CNS effects). Where available, integrase inhibitor-based regimens are now preferred in most global guidelines. Efavirenz remains first-line in many resource-limited settings due to generic availability, established safety, and cost — providing effective HIV control where newer agents are unaffordable.

Is Efavir 600mg equivalent to Sustiva 600mg?

Yes. Efavir 600mg and branded Sustiva 600mg both contain efavirenz 600mg in bioequivalent once-daily formulations. Efavir is the generic alternative providing the same HIV NNRTI therapy at significantly lower cost — making efavirenz-based first-line HIV treatment accessible in price-sensitive markets.

Can I order Efavir 600mg from PremiumRxDrugs for international delivery?

Yes. PremiumRxDrugs.com ships Efavir 600mg to the USA, UK, Australia, and many other countries. Our genuine manufacturer-verified antiretrovirals, competitive pricing, and free worldwide shipping on qualifying orders make us a reliable international pharmacy for efavirenz-based HIV therapy.

What side effects and precautions are most important with Efavir 600mg?

Most important: CNS effects (dizziness, vivid dreams — bedtime dosing essential); psychiatric effects (depression, suicidal ideation — monitor each visit); teratogenicity potential (effective contraception mandatory for women of childbearing age); drug interactions via CYP3A4 induction (always review co-medications); skin rash (maculopapular rash in 10–15%, typically mild and self-limiting; Stevens-Johnson syndrome very rare). Do not stop efavirenz without specialist guidance. Resistance testing before initiation prevents starting on an already-resistant virus. Report any severe skin reactions, worsening depression, or suicidal thoughts immediately.

What should I know about switching away from efavirenz 600mg to a different HIV regimen?

Switching from efavirenz to an integrase inhibitor (dolutegravir, bictegravir) is increasingly common — motivated by ongoing CNS side effects, lipid issues, drug interactions, or pregnancy planning. Switching is safe and effective when virologically suppressed: simply switch efavirenz for the new agent while maintaining the same NRTI backbone. A 'lead-in' period is not required. After switching, CNS symptoms resolve within days to weeks. Lipid levels may improve. Contraceptive requirements change (hormonal contraception becomes reliable again). Genotypic resistance testing before switching is advisable to ensure the NRTI backbone is fully active.

SKU	362
Generic For	N/A
Strength	600 mg
Active Ingredient	Efavirenz

Efavir 600mg