title: Resistance profiles in patients with viral rebound on potent antiretroviral therapy.
abstract: The prevalence of phenotypic drug resistance was assessed in 60 patients with a viral rebound after they received a protease inhibitor (PI)- or nonnucleoside reverse transcriptase inhibitor (NNRTI)-containing regimen (baseline). Resistance testing was done within 36 weeks of viral rebound; no resistance testing was available at baseline. All patients had previously received zidovudine; 86.0% had received lamivudine. In total, 45.1% of the patients had strains resistant to the PI that they started and 88.9% given nevirapine had strains with reduced susceptibility to that drug. Overall, 46 patients (76.7%) harbored a strain resistant to >/=1 drug of their initial PI- or NNRTI-containing regimen. Of 53 patients who remained on treatment at the time of the study (40 had switched to a different combination from that at baseline), 6 harbored isolates susceptible to all drugs they had ever received. Thus, patients with viral rebound while on potent antiretroviral therapy usually have reduced susceptibility to >/=1 drug. Viral rebound also occurs in persons in whom resistant strains could not be detected by the assay used.
authors.affiliation: Royal Free Centre for HIV Medicine and Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Cozzi Lepri
authors.forename: C A
authors.initials: CA
authors.lastname: Sabin
authors.forename: S
authors.initials: S
authors.lastname: Staszewski
authors.forename: K
authors.initials: K
authors.lastname: Hertogs
authors.forename: A
authors.initials: A
authors.lastname: Müller
authors.forename: H
authors.initials: H
authors.lastname: Rabenau
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: V
authors.initials: V
authors.lastname: Miller
mesh_terms: D004351:Drug Resistance; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D006801:Humans; D010641:Phenotype; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*
chemical_list: D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors