Contribution of different antiretroviral regimens containing zidovudine, lamivudine and ritonavir-boosted lopinavir on HIV viral load reduction during pregnancy.
Antiretroviral (ARV) regimens used for the prevention of mother-to-child transmission of HIV have evolved over time. We evaluated the contribution of different ARV regimens on the reduction of the plasma HIV RNA viral load (VL) during pregnancy.



A total of 1,833 VL measurements from ARV-naive pregnant women participating in perinatal prevention trials in Thailand were included. Women received either zidovudine (ZDV) monotherapy, ZDV plus lopinavir/ritonavir (LPV/r), or ZDV plus lamivudine (3TC) plus LPV/r. VL time-course during pregnancy was described as a function of pretreatment VL and treatment duration using an Emax non-linear mixed-effect model. VL reduction and median time to achieve a VL<50 copies/ml were estimated for each regimen.



Among 745 women, 279 (37%), 145 (20%) and 321 (43%) received ZDV monotherapy, ZDV+LPV/r and ZDV+3TC+LPV/r, respectively. The predicted VL reduction from baseline to delivery after a median of 10 weeks of treatment were 0.5, 2.7 and 2.9 log10 copies/ml with ZDV monotherapy, ZDV+LPV/r and ZDV+3TC+LPV/r, respectively. At delivery, 1%, 57% and 63% of women receiving ZDV monotherapy, ZDV+LPV/r or ZDV+3TC+LPV/r had a VL<50 copies/ml. The addition of 3TC to ZDV+LPV/r reduced the time to achieve a VL<50 copies/ml and the higher the pretreatment VL, the larger the effect 3TC had on reducing the time to VL<50 copies/ml.



The addition of 3TC to ZDV+LPV/r was associated with a slight further VL reduction but the time to reach a VL<50 copies/ml was shorter. This beneficial effect of 3TC is crucial for prevention of mother-to-child transmission in women who receive ARVs late and with high pretreatment VL.
Department of Statistics, Faculty of Science, Kasetsart University, Bangkok, Thailand.
Patumrat
P
Sripan
Sophie
S
Le Coeur
Lily
L
Ingsrisawang
Tim R
TR
Cressey
Naïm
N
Bouazza
Frantz
F
Foissac
Nicole
N
Ngo-Giang-Huong
Patrinee
P
Traisathit
Ussanee
U
Srirompotong
Orada Patamasingh Na
OP
Ayudhaya
Achara
A
Puangsombat
Jantana
J
Jungpipun
Kanokwan
K
Jittayanun
Jean-Marc
JM
Tréluyer
Gonzague
G
Jourdain
Marc
M
Lallemant
Saïk
S
Urien
D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D019259:Lamivudine / Q000008:administration & dosage; D061466:Lopinavir / Q000008:administration & dosage; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy* / Q000821:virology*; D019438:Ritonavir / Q000008:administration & dosage; D013785:Thailand; D019562:Viral Load / Q000187:drug effects; D015215:Zidovudine / Q000008:administration & dosage
D019380:Anti-HIV Agents; D061466:Lopinavir; D019259:Lamivudine; D015215:Zidovudine; D019438:Ritonavir