ABSTRACT
The 20,30-dideoxynucleoside (ddN) analogs have become the cornerstone in the chemotherapy of HIV infections, because virtually all drug combination regimens that are currently used for AIDS treatment contain one or more ddN analogs. In these AIDS treatment regimes, the ddN analogs (also commonly referred to as NRTIs for nucleoside reverse transcriptase inhibitors) are combined with non-nucleoside reverse transcriptase inhibitors (NNRTIs) and/or protease inhibitors (PIs). The following NRTIs have been formally approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infections: zidovudine (ZDV), didanosine (ddI), zalcitabine (ddC), stavudine (d4T), lamivudine (3TC), and abacavir (ABC). In the meantime, the nucleotide reverse transcriptase inhibitor (NtRTI) tenofovir disoproxil fumarate has also been approved by both the FDA and their European
counterpart, the European Agency for the Evaluation of Medicinal Products (EMEA). Also, the combinations of ZDV with 3TC, and of ZDV with 3TC and ABC, have been formally approved, so that there are now nine preparations registered as NtRTIs or NRTIs (Table 1). Further details on the dates of approval, the trade names, dosage level, and principal side effects are listed in Table 1 [1].
