Current antiretroviral therapy Nucleoside(analogue) reverse transcriptase inhibitors(NRTI) competitive inhibitors of reverse transcriptase by competing with natural pyrimidines(AzT, d4T [stavudine) or purines(ddl [didanosine]) and inhibiting chain elongation Non- nucleoside reverse transcriptase inhibitors(NNrTI) noncompetitive inhibitors of RT by binding to a pocket near the reverse transcriptase active site, changing its conformation and so inactivating it Protease inhibitors Competitive inhibitors-rationally designed, based on the 3D structure of Hiv protease revent proteolytic cleavage of final translation product necessary for assembly and release of virus Attachment prevention Prevents fusion of the virus to the cell membrane