Nevirapine was approved for use in 1996 in the US. Nevirapine belongs to the class of non-nucleotide reverse transcriptase inhibitors (NNRTIs). After the HIV virus enters the host cell, the HIV RNA strand is released, and the single strand RNA is reverse transcribed to form DNA by reverse transcriptase. The drug inhibits the formation of DNA, reduces the amount of HIV virus.

Efavirenz was approved for use in 1998 in the US. Efavirenz belongs to the group of non-nucleotide reverse transcriptase inhibitors. After the HIV virus enters the host cell, the HIV RNA strand is released, and the single strand RNA is reverse transcribed to form DNA by reverse transcriptase. Reverse transcriptase inhibitors, which prevent viral RNA from being copied into DNA, prevent HIV from replicating.

The first case of HIV infection in the world was discovered in the US in 1981. The first case of HIV infection was discovered in Vietnam in 1990 in Ho Chi Minh City. As of August 2020, there are about 213,008 living HIV infections in Vietnam. Of these, more than 153,000 people living with HIV are on antiretroviral therapy (ARV).