RICOVIR-EM Tablets RICOVIR-EM is a fixed-dose combination of Emtricitabine (a nucleoside reverse transcriptase inhibitor) and Tenofovir Disoproxil Fumarate (a nucleotide reverse transcriptase inhibitor). Both active agents undergo intracellular phosphorylation to their respective active triphosphates (emtricitabine 5'-triphosphate and tenofovir diphosphate). These active metabolites competitively inhibit HIV-1 reverse transcriptase by competing with natural substrates, resulting in viral DNA chain termination and inhibition of viral replication. It is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection and as pre-exposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 infection in high-risk individuals.