TL;DR
- Sustiva (efavirenz) is a non‑nucleoside reverse transcriptase inhibitor used in combination therapy for HIV‑1.
- Standard adult dose: 600mg once daily, taken on an empty stomach.
- Common side effects: dizziness, vivid dreams, rash, and mood changes.
- Watch for interactions with certain anticonvulsants, rifampin, and St.John’s wort.
- Never stop or change dose without consulting your HIV specialist.
What is Sustaina? - An Overview
Sustiva is the brand name for efavirenz, a drug that belongs to the non‑nucleoside reverse transcriptase inhibitor (NNRTI) class. It’s a cornerstone of first‑line antiretroviral therapy (ART) for people living with HIV‑1. The medication works by binding directly to the viral reverse transcriptase enzyme, halting the conversion of viral RNA into DNA-a crucial step for HIV replication.
Because HIV can quickly develop resistance, doctors almost always prescribe Sustaina together with two other antiretrovirals from different classes (usually a nucleoside reverse transcriptase inhibitor+a protease inhibitor or integrase inhibitor). This combination keeps the virus suppressed, preserves immune function, and reduces the risk of opportunistic infections.
How Sustaina Works in the Body
Efavirenz targets the reverse transcriptase enzyme at a specific pocket, causing a conformational change that makes the enzyme inactive. Unlike nucleoside analogs, it does not need to be phosphorylated inside cells, which means it reaches its peak activity faster. Its half‑life is long-about 40‑55hours-allowing once‑daily dosing.
Because the drug is lipophilic, it penetrates the central nervous system (CNS) well. That’s why patients often notice CNS‑related side effects early on. The long half‑life also means that missed doses can lead to sub‑therapeutic levels, increasing the chance of resistance.
Dosage & Administration: Getting It Right
Proper dosing is essential for effectiveness and safety. Below is a quick‑reference table that outlines the most common dosing scenarios.
| Patient Group | Typical Dose | Administration Tips |
|---|---|---|
| Adults (≥18years) | 600mg PO once daily | Take on an empty stomach (≥1hour before or ≥2hours after food). Swallow whole; do not crush. |
| Adults with hepatic impairment (Child‑Pugh B) | 400mg PO once daily | Same fasting rule; monitor liver enzymes. |
| Pediatric (≥3years, weight ≥25kg) | 400mg PO once daily | Chef‑approved pediatric formulation; follow fasting guidelines. |
| Pregnant women (first trimester) | Consult specialist | Potential teratogenic risk; only continue if benefits outweigh risks. |
Key points to remember:
- Take Sustaina at the same time each day to maintain steady plasma levels.
- If you miss a dose, take it as soon as you remember-only if it’s more than 12hours before the next scheduled dose.
- Do not double‑dose to make up for a missed one.
- Alcohol can increase CNS side effects; limit intake.
Side Effects & Safety: What to Watch For
Most people tolerate Sustaina well, but the drug’s ability to cross the blood‑brain barrier explains why it has a distinct side‑effect profile.
- Common (≥10% incidence): dizziness, headache, insomnia, vivid dreams, nausea, and mild rash.
- Less common (1‑10%): depression, anxiety, hallucinations, suicidal thoughts, and severe skin reactions (Stevens‑Johnson syndrome).
- Rare (<1%): hepatotoxicity, pancreatitis, and significant lipid abnormalities.
If you notice any of the following, call your healthcare provider immediately:
- Severe rash or blistering skin.
- Persistent thoughts of self‑harm or worsening depression.
- Jaundice, dark urine, or abdominal pain (signs of liver trouble).
- Unexplained fever or swollen lymph nodes.
Routine labs-liver enzymes, fasting lipids, and CD4 count-should be checked every 3‑6months while on therapy.
Drug Interactions & Precautions
Efavirenz is a potent inducer of cytochromeP4503A4 and 2B6. It can lower the levels of many co‑administered drugs, and some agents can increase efavirenz concentrations, raising toxicity risk.
| Interacting Drug | Effect on Sustaina | Clinical Action |
|---|---|---|
| Rifampin (TB treatment) | Decreases efavirenz levels | Increase efavirenz to 800mg daily if tolerated. |
| Nevirapine | Similar NNRTI class - avoid co‑administration | Choose alternative regimen. |
| St.John’s wort | Induces metabolism → lower efavirenz | Discontinue herbal supplement. |
| Azole antifungals (ketoconazole, itraconazole) | Increase efavirenz levels | Monitor for CNS toxicity; consider dose reduction. |
| Warfarin | May decrease INR | Check INR more frequently. |
Patients with moderate to severe hepatic impairment should start at a reduced dose and be monitored closely. Because efavirenz can affect hormone‑based contraceptives, discuss backup birth control methods with your provider.
Frequently Asked Questions
- Can I take Sustaina with food? The recommendation is to take it on an empty stomach. Food, especially high‑fat meals, can lower absorption and increase plasma variability.
- Will I get a “high” from the drug? No. The CNS effects are side effects-not euphoria. They usually lessen after 2‑4weeks as the body adjusts.
- Is it safe during pregnancy? Efavirenz is classified as FDA Pregnancy Category D. It’s linked to neural‑tube defects when used in the first trimester. If you become pregnant, discuss risk‑benefit with your HIV specialist.
- How long will I need to stay on Sustaina? As long as your HIV regimen includes it and you maintain viral suppression. Discontinuation should be done under medical supervision to avoid resistance.
- Can I drink alcohol? Moderate consumption is generally tolerated, but alcohol can worsen dizziness, insomnia, and mood changes.
Next Steps & Troubleshooting
If you’re starting Sustaina, follow this quick‑start checklist:
- Schedule a baseline lab panel (CBC, liver function, lipids, HIV viral load, CD4 count).
- Set a daily reminder for the same pill‑time each day.
- Keep a symptom diary for the first 4weeks-note any vivid dreams, mood swings, or rash.
- Set an appointment with your prescriber after 1month to review labs and side‑effect profile.
- Never adjust dose on your own; contact the clinic if you miss more than two consecutive doses.
Should you encounter intolerable side effects, options include dose reduction (if clinically appropriate) or switching to another NNRTI or an integrase strand transfer inhibitor (INSTI)‑based regimen. Always discuss the change with a provider who can evaluate resistance patterns.
Staying informed, adhering to the schedule, and maintaining open communication with your care team are the best ways to keep HIV under control while on Sustaina. Remember: the medication works best when you take it exactly as prescribed.