Is Atripla affected by genetics?
Partially. 1 of 3 ingredients has pharmacogenetic evidence.
Atripla contains 3 active ingredients, and 1 of them has published pharmacogenetic guidelines. The relevant gene is CYP2B6. Your genotype can change how that ingredient behaves in your body, while the other ingredients aren't affected by genetics in any clinically established way. The strongest evidence level on this page is Strong, from the published guidelines shown below.
Pharmacogenetic guidelines are written for one ingredient at a time, so the guidance below is for each ingredient on its own. What your genes mean for a combination product is less clear, because the dose and the other ingredients can change things. If you take Atripla, it's worth talking over with your prescriber or pharmacist. How we handle combination products.
What's in Atripla
Efavirenz Affected by CYP2B6
Affected by CYP2B6. Guidance from CPIC, FDA, strong evidence.
Read the full efavirenz genetics guideEmtricitabine No known pharmacogenetics
No strong published pharmacogenetic guideline currently applies to emtricitabine.
Tenofovir disoproxil No known pharmacogenetics
No strong published pharmacogenetic guideline currently applies to tenofovir disoproxil.
Efavirenz phenotype recommendations
Published guidance from CPIC and FDA on how efavirenz should be dosed or substituted based on your CYP2B6 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
| Ultrarapid MetabolizerCYP2B6 | Your body breaks down this drug a little faster, but the usual dose should still work for you. | CPIC Initiate efavirenz with standard dosing (600 mg/day) FDA Initiate therapy with recommended starting dose. |
Strong |
| Ultra Rapid MetabolizerCYP2B6 | Your body breaks down this drug a little faster, but the usual dose should still work for you. | CPIC Initiate efavirenz with standard dosing (600 mg/day) FDA Initiate therapy with recommended starting dose. |
Strong |
| Rapid MetabolizerCYP2B6 | Your body breaks down this drug a little faster, but the usual dose should still work for you. | CPIC Initiate efavirenz with standard dosing (600 mg/day) FDA Initiate therapy with recommended starting dose. |
Strong |
| Normal MetabolizerCYP2B6 | Your body processes efavirenz normally. The standard dose is expected to be appropriate for you. | CPIC Initiate efavirenz with standard dosing (600 mg/day) FDA Initiate therapy with recommended starting dose. |
Strong |
| Intermediate MetabolizerCYP2B6 | Your body breaks down this drug more slowly, so it can build up and cause side effects like dizziness or trouble sleeping. A lower starting dose may be suggested. | CPIC Consider initiating efavirenz with decreased dose of 400 mg/day. FDA Initiate therapy with recommended starting dose. |
Moderate |
| Poor MetabolizerCYP2B6 | Your body breaks down this drug much more slowly, so side effects like dizziness, trouble sleeping or mood changes are more likely. A lower dose is often suggested. | CPIC Consider initiating efavirenz with decreased dose of 400 or 200 mg/day. FDA No specific dosing change in the FDA table. Refer to FDA labeling. |
Strong |
| IndeterminateCYP2B6 | The impact of your genotype on response to this drug is unknown | CPIC + FDA Initiate therapy with recommended starting dose. |
Not rated |
| Not availableCYP2B6 | The impact of your genotype on response to this drug is unknown | CPIC + FDA Initiate therapy with recommended starting dose. |
Not rated |
The gene behind the guidance
CYP2B6 Cytochrome P450 2B6
CYP2B6 handles efavirenz (an older HIV drug), bupropion, methadone, and ketamine. The most consequential allele is *6, which dramatically reduces activity and is common across many populations. Carriers accumulate much higher efavirenz levels and are at greater risk of CNS side effects like vivid dreams and depression.
CPIC recommends a lower starting efavirenz dose for poor and intermediate CYP2B6 metabolizers. The dose-response relationship is strong enough that some clinicians measure drug levels directly.
See all drugs affected by CYP2B6Related medications
Find out how your genetics affect Atripla
Informational only, not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.