Table 1.

HAART currently in use in the clinical practice.

Classes of drugs	Phase of the retroviral life-cycle targeted
Entry inhibitors (EIs)	They interfere with binding, fusion, and entry of HIV-1 to the host cell
CCR5 receptor antagonists (CCR5RAs)	They bind to the CCR5 receptor on the surface of the T-Cell and block viral attachment to the cell. If HIV cannot attach to the cell, it cannot gain entry to replicate
Nucleoside reverse transcriptase inhibitors (NsRTIs) and nucleotide reverse transcriptase inhibitors (NtRTIs)	They inhibit reverse transcription by being incorporated into the newly synthesized viral DNA strand as faulty nucleotides; they both act as competitive substrate inhibitors
Non-nucleoside reverse transcriptase inhibitors (NNRTIs)	They inhibit reverse transcriptase by binding to an allosteric site of the enzyme; NNRTIs act as non-competitive inhibitors of reverse transcriptase
Protease inhibitors (PIs)	They target viral assembly by inhibiting the activity of protease, an enzyme used by HIV to cleave nascent proteins for the final assembly of new virions
Integrase inhibitors (IIs)	They inhibit the enzyme integrase, which is responsible for integration of viral DNA into the DNA of the infected cell
Maturation inhibitors (MIs)	They inhibit the last step in gag processing in which the viral capsid polyprotein is cleaved, thereby blocking the conversion into mature capsid protein