title: Comparison of four-drug regimens and pairs of sequential three-drug regimens as initial therapy for HIV-1 infection.
abstract: BACKGROUND
  It is unclear whether therapy for human immunodeficiency virus type 1 (HIV-1) should be initiated with a four-drug or two sequential three-drug regimens.
  
  
  METHODS
  In this multicenter trial we compared initial therapy involving four-drug regimens containing efavirenz and nelfinavir in combination with either didanosine and stavudine or zidovudine and lamivudine with therapy involving two consecutive three-drug regimens the first of which contained either efavirenz or nelfinavir.
  
  
  RESULTS
  A total of 980 subjects were followed for a median of 2.3 years. There was no significant difference in the occurrence of regimen failures between the group that received the four-drug regimen containing didanosine, stavudine, nelfinavir, and efavirenz and the groups that received the three-drug regimens beginning with didanosine, stavudine, and nelfinavir (hazard ratio for regimen failure, 1.24) or didanosine, stavudine, and efavirenz (hazard ratio, 1.01). There was no significant difference between the group that received the four-drug regimen containing zidovudine, lamivudine, nelfinavir, and efavirenz and the groups that received the three-drug regimens beginning with zidovudine, lamivudine, and nelfinavir (hazard ratio, 1.06) or zidovudine, lamivudine, and efavirenz (hazard ratio, 1.45). A four-drug regimen was associated with a longer time to the first regimen failure than the three-drug regimens containing didanosine, stavudine, and nelfinavir (hazard ratio for a first regimen failure, 0.55); didanosine, stavudine, and efavirenz (hazard ratio, 0.63); or zidovudine, lamivudine, and nelfinavir (hazard ratio, 0.49), but not the three-drug regimen containing zidovudine, lamivudine, and efavirenz (hazard ratio, 1.21).
  
  
  CONCLUSIONS
  There was no significant difference in the duration of successful HIV-1 treatment between a single four-drug regimen and two consecutive three-drug regimens. Among these treatment strategies, initiating therapy with the three-drug regimen of zidovudine, lamivudine, and efavirenz is the optimal choice.
authors.affiliation: Stanford University Medical Center, Stanford, Calif, USA. grobbins@partners.org
authors.forename: Robert W
authors.initials: RW
authors.lastname: Shafer
authors.forename: Laura M
authors.initials: LM
authors.lastname: Smeaton
authors.forename: Gregory K
authors.initials: GK
authors.lastname: Robbins
authors.forename: Victor
authors.initials: V
authors.lastname: De Gruttola
authors.forename: Sally W
authors.initials: SW
authors.lastname: Snyder
authors.forename: Richard T
authors.initials: RT
authors.lastname: D'Aquila
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Johnson
authors.forename: Gene D
authors.initials: GD
authors.lastname: Morse
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: Nokta
authors.forename: Ana I
authors.initials: AI
authors.lastname: Martinez
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Gripshover
authors.forename: Pamposh
authors.initials: P
authors.lastname: Kaul
authors.forename: Richard
authors.initials: R
authors.lastname: Haubrich
authors.forename: Mary
authors.initials: M
authors.lastname: Swingle
authors.forename: S Debra
authors.initials: SD
authors.lastname: McCarty
authors.forename: Stefano
authors.initials: S
authors.lastname: Vella
authors.forename: Martin S
authors.initials: MS
authors.lastname: Hirsch
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Merigan
mesh_terms: D000328:Adult; D000480:Alkynes; D044966:Anti-Retroviral Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D048588:Benzoxazines; D018791:CD4 Lymphocyte Count; D003521:Cyclopropanes; D016049:Didanosine / Q000008:administration & dosage; D004311:Double-Blind Method; D024882:Drug Resistance, Viral / Q000235:genetics; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D019259:Lamivudine / Q000008:administration & dosage; D008297:Male; D009154:Mutation; D019888:Nelfinavir / Q000008:administration & dosage; D010078:Oxazines / Q000008:administration & dosage; D018119:Stavudine / Q000008:administration & dosage; D013997:Time Factors; D017211:Treatment Failure; D015215:Zidovudine / Q000008:administration & dosage
chemical_list: D000480:Alkynes; D044966:Anti-Retroviral Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D010078:Oxazines; D019259:Lamivudine; D015215:Zidovudine; D018119:Stavudine; D019888:Nelfinavir; C098320:efavirenz; D016049:Didanosine