There is no harmful interaction expected between the two drugs. They work well and can be coadministered. Although these drugs can be used together, a doctor’s prescription is highly recommended.
Truvada is a highly potent drug prescribed for use in the following cases:
Truvada has two active substances: emtricitabine (EM) and tenofovir-DF (TDF) that belong to the NRTI drug class.
Sustiva is a powerful first-line antiretroviral medication belonging to a class of NNRTIs and having efavirenz as an active substance. It’s used to treat HIV in combination with other NRTI or protease inhibitor.
This highly effective med reduces viral load (HIV-1) substantially in six months in 60 to 80% of treatment-naïve patients. Efavirenz is not active against HIV-2 [3].
While there is no significant drug interaction between these two meds, clinical tests show a very minimal interaction between individual active substances.
From a study based on 9 treatment-naïve patients, when coadministering efavirenz and emtricitabine in the presence of didanosine, the pharmacokinetics of emtricitabine were not affected. In contrast, didanosine Cmax and AUC were higher than expected, and efavirenz Cmin, Cmax, and AUC were lower than expected.
Coadministration of efavirenz and tenofovir-DF decreased efavirenz AUC and Cmax both by 4%. TDF Cmax increased by 7% and AUC decreased by 1%. From these clinical results, there is no need for dosage adjustment of efavirenz when coadministered with Truvada [4].
While taking these meds concomitantly, a doctor’s supervision is necessary. Efavirenz can cause liver problems, and using it with TDF/EM or any other med known to induce hepatotoxicity may increase that risk. Avoid or limit the use of alcohol while being medicated with these drug stack [5].