Drug interactions
Efavirenz + Lamivudine
Severity: Minor
Efavirenz and Lamivudine: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Immune reconstitution inflammatory syndrome can occur when any effective antiretroviral regimen is started, so it reflects the overall regimen and not a specific interaction between these two drugs. They are routinely combined, with no pharmacological interaction of concern.
What this interaction means in plain words
Efavirenz and Lamivudine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Efavirenz belongs to Anti Virals; Lamivudine belongs to Anti Virals.
Why it happens
No pharmacokinetic or pharmacodynamic interaction; immune reconstitution follows recovery of immunity with effective antiretroviral therapy.
What to do
No change to therapy is needed. Monitor for new inflammatory symptoms of opportunistic infection in the first weeks to months after starting treatment.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Lamivudine
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Lamivudine?
MediHelp rates the interaction as minor. Efavirenz and Lamivudine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Immune reconstitution inflammatory syndrome can occur when any effective antiretroviral regimen is started, so it reflects the overall regimen and not a specific interaction between these two drugs. They are routinely combined, with no pharmacological interaction of concern.
How serious is the interaction between Efavirenz and Lamivudine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No change to therapy is needed. Monitor for new inflammatory symptoms of opportunistic infection in the first weeks to months after starting treatment.
What other medicines interact with Lamivudine?
MediHelp also lists interactions of Lamivudine with, for example, Elvitegravir / cobicistat / emtricitabine / tenofovir df, Atidarsagene autotemcel, Betibeglogene autotemcel. The full list is on the Lamivudine page.
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