Reverse Transcriptase InhibitorsHIV Reverse TranscriptaseDrug Resistance, ViralAnti-HIV AgentsBenzoxazinesNevirapinePyridazinesHIV-1HIV InfectionsDelavirdineAntiretroviral Therapy, Highly ActiveViral LoadHIV Protease InhibitorsOxazinesAnti-Retroviral AgentsCD4 Lymphocyte CountTreatment FailureRibonuclease H, Human Immunodeficiency VirusMutation, MissensePyrimidinonesMutationZidovudineLopinavirRNA, ViralHIVNucleosidesHIV ProteaseRitonavirProtease InhibitorsNitrilesDrug Therapy, CombinationOrganophosphonatesGenotypeRibonuclease HAmino Acid SubstitutionLamivudineTreatment OutcomePatient ComplianceAdenineDrug Administration ScheduleCohort StudiesVirus ReplicationModels, MolecularAcquired Immunodeficiency SyndromePyrimidinesDrug InteractionsMolecular StructureMicrobial Sensitivity TestsTime FactorsSequence Analysis, DNAPrevalenceCell LineRetrospective StudiesMolecular Sequence DataStructure-Activity RelationshipProspective Studies