There are no clinically significant interactions when emtricitabine is co-administered with indinavir, zidovudine, stavudine, famciclovir or tenofovir disoproxil fumarate.
Emtriva Summary of Product Characteristics, Gilead Sciences Ltd, April 2019.

No significant interactions were observed between emtricitabine and tenofovir. Coadministration of emtricitabine (200 mg once daily for 7 days) and tenofovir (300 mg once daily for 7 days) was studied in 17 HIV-negative subjects. There was no change in emtricitabine AUC and Cmax and a 20% increase in Cmin. Tenofovir AUC, Cmax and Cmin were unaltered.
Emtriva Prescribing Information, Gilead Sciences Inc, December 2018.

There were no clinically significant pharmacokinetic interactions when tenofovir disoproxil fumarate was coadministered with emtricitabine.
Viread Summary of Product Characteristics, Gilead Sciences Ltd, September 2016.

Coadministration of tenofovir-DF (300 mg once daily) and emtricitabine (200 mg once daily for 7 days) was studied in 17 HIV-negative subjects. There was no change in tenofovir pharmacokinetic parameters. Emtricitabine AUC and Cmax were unaltered and there was a 20% increase in Cmin.
Viread Prescribing Information, Gilead Sciences International Inc, February 2016.