Diclofenac and Efavirenz, lamivudine, and tenofovir interaction
Diclofenac and Efavirenz, lamivudine, and tenofovir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Efavirenz, lamivudine, and tenofovir (SYMFI) label · effective 2019-10-15
Avoid SYMFI with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple non-steroidal anti-inflammatory drugs [NSAIDs]) [see Drug Interactions (7.3) ] .
Cases of acute renal failure after initiation of high-dose or multiple NSAIDs have been reported in HIV-infected patients with risk factors for renal dysfunction who appeared stable on TDF.
Alternatives to NSAIDs should be considered, if needed, in patients at risk for renal dysfunction.
Some examples include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.4) ] .
From the Diclofenac (ZIPSOR) label · effective 2026-03-01
Co-administration of diclofenac with CYP2C9 inhibitors (e.g. voriconazole) may enhance the exposure and toxicity of diclofenac whereas co- administration with CYP2C9 inducers (e.g. rifampin) may lead to compromised efficacy of diclofenac.
Intervention: A dosage adjustment may be warranted when diclofenac is administered with CYP2C9 inhibitors or inducers [ see Clinical Pharmacology ( 12.3 ) ] Drugs that Interfere with Hemostasis (e.g. warfarin, aspirin, SSRIs/SNRIs) : Monitor patients for bleeding who are concomitantly taking ZIPSOR with drugs that interfere with hemostasis.
CYP2C9 Inhibitors or Inducers: Clinical Impact Diclofenac is metabolized by cytochrome P450 enzymes, predominantly by CYP2C9.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.