Common use

Sustiva is a potent antiretroviral medication containing efavirenz, used as a cornerstone of HIV treatment regimens worldwide. If you are looking to buy Sustiva online, it is important to understand that this medication belongs to the non-nucleoside reverse transcriptase inhibitor (NNRTI) class of antiretroviral drugs. Efavirenz works by directly binding to and blocking the reverse transcriptase enzyme, which HIV uses to convert its RNA into DNA — a critical step in viral replication. By inhibiting this process, Sustiva helps reduce the viral load in the bloodstream and supports immune system recovery.

Sustiva is prescribed for the treatment of human immunodeficiency virus type 1 (HIV-1) infection and is used in combination with other antiretroviral medications as part of highly active antiretroviral therapy (HAART). This HIV medication is also used to prevent the development of acquired immunodeficiency syndrome (AIDS) in individuals who have been exposed to HIV through sexual contact, needlestick injuries, or other occupational exposures to HIV-infected material. Sustiva generic versions containing efavirenz offer the same antiviral efficacy as the brand-name product, making essential AIDS treatment more accessible and affordable for patients who need long-term HIV medication management.



Dosage and direction

The recommended dose of Sustiva for adults and adolescents weighing over 40 kg is 600 mg taken once daily, preferably on an empty stomach and at bedtime. Taking efavirenz before sleep helps minimize central nervous system side effects such as dizziness and vivid dreams, which are most common during the first two to four weeks of treatment.

Pediatric dosing is based on body weight: children weighing 13-15 kg should receive 200 mg daily; 15-20 kg should receive 250 mg; 20-25 kg should receive 300 mg; 25-32.5 kg should receive 350 mg; and 32.5-40 kg should receive 400 mg. Children weighing over 40 kg should take the full adult dose of 600 mg.

Sustiva must always be taken as part of a combination antiretroviral regimen — never as monotherapy. Consistent daily dosing is essential to maintain adequate drug levels, reduce viral load effectively, and prevent the development of drug-resistant HIV strains. Buy efavirenz only with a prescription and follow your healthcare provider's instructions exactly.



Precautions

Before you buy Sustiva online or begin efavirenz therapy, discuss your complete medical history with your doctor. Inform your healthcare provider if you have liver or kidney impairment, a history of alcohol or substance abuse, hepatic encephalopathy, elevated cholesterol or triglycerides, or liver disease including hepatitis B or C co-infection.

Tell your doctor if you have previously taken other NNRTIs such as delavirdine (Rescriptor) or nevirapine (Viramune) without achieving a therapeutic response, as cross-resistance within the NNRTI class may affect the efficacy of Sustiva as an HIV medication.

Special caution is required for children under 3 years of age and those weighing less than 13 kg. Efavirenz has been shown to cause serious birth defects in animal studies, so reliable contraception is absolutely essential for women of childbearing age during antiretroviral treatment and for 12 weeks after discontinuation. This AIDS treatment medication is classified as pregnancy category D.

Regular monitoring of viral load, CD4 cell counts, liver function tests, and lipid panels is recommended during Sustiva therapy. Psychiatric symptoms including depression, suicidal thoughts, and psychosis have been reported — seek immediate medical attention if these occur.



Contraindications

Sustiva (efavirenz) is contraindicated in patients with known hypersensitivity to efavirenz or any component of the formulation. This antiretroviral medication must not be used by pregnant women or women planning to become pregnant due to the risk of fetal harm. Breastfeeding is contraindicated during HIV treatment to prevent mother-to-child transmission of the virus. Sustiva should not be co-administered with certain medications that rely on CYP3A4 for clearance and have narrow therapeutic windows, as dangerous interactions may occur.



Side effects

Sustiva may cause significant psychiatric and central nervous system symptoms, particularly during the first weeks of treatment. Inform your doctor immediately if you experience hallucinations, suicidal thoughts, severe depression, confusion, aggression, extreme fear, paranoia, or unusual behavior. These neuropsychiatric effects typically diminish after 2-4 weeks of consistent efavirenz therapy.

Common side effects of this HIV medication include dizziness, headache, difficulty concentrating, vivid or abnormal dreams, insomnia, fatigue, rash, nausea, and diarrhea. Skin rash occurs in approximately 25% of patients but is usually mild to moderate and resolves without discontinuation.

Serious side effects requiring immediate medical attention include severe skin reactions (Stevens-Johnson syndrome), liver toxicity (jaundice, dark urine, abdominal pain), and significant elevations in cholesterol or triglycerides. Long-term use of antiretroviral therapy may also be associated with changes in body fat distribution (lipodystrophy).



Drug interaction

Efavirenz is a potent inducer and inhibitor of several cytochrome P450 enzymes, resulting in numerous significant drug interactions. Sustiva decreases blood concentrations and therapeutic effects of indinavir (Crixivan) and saquinavir (Invirase), potentially compromising viral load suppression.

Concomitant use with alcohol may amplify the central nervous system effects of this NNRTI medication. Co-administration with astemizole or cisapride increases the risk of serious cardiac arrhythmias. Sustiva reduces the effectiveness of hormonal contraceptives — alternative or additional contraceptive methods are strongly recommended.

If Sustiva is used together with ritonavir, the combination may increase both side effects and hepatotoxicity risk. Concomitant use with clarithromycin or saquinavir should be avoided or carefully managed. Midazolam (Versed) and triazolam (Halcion) are contraindicated with efavirenz due to excessive sedation risk. Phenobarbital may decrease Sustiva blood concentrations below therapeutic levels.

Do not take Sustiva with pimozide (Orap), cisapride (Propulsid), ergot-derived medications such as ergotamine (Cafergot), dihydroergotamine, ergonovine (Ergotrate), or methylergonovine (Methergine). Co-administration with rifabutin or rifampin requires careful dose adjustment. Always inform your doctor of all medications you are taking before starting this antiretroviral treatment.



Missed dose

Consistent daily dosing is critical for effective HIV treatment and viral load control. If you forget to take your dose of Sustiva, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, skip the missed dose and resume your regular schedule. Do not take double doses of this antiretroviral medication. Missing doses of efavirenz can allow the virus to replicate and may promote the development of drug-resistant HIV strains, so adherence to your prescribed regimen is essential.



Overdose

In case of suspected Sustiva overdose, seek urgent medical attention immediately. Symptoms may include involuntary muscle twitching, increased central nervous system effects such as dizziness, confusion, and impaired coordination. There is no specific antidote for efavirenz overdose — treatment is supportive and symptomatic. Contact your local poison control center or emergency services for guidance.



Storage

Store Sustiva at room temperature between 68-77 degrees F (20-25 degrees C). Keep the medication away from moisture, heat, and direct sunlight. Do not store this HIV medication in the bathroom. Keep all antiretroviral drugs out of reach of children and pets. Dispose of expired efavirenz or Sustiva generic products according to local pharmacy guidelines.



Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.