A pilot study to evaluate the safety and feasibility of the administration of AZT/3TC fixed dose combination to HIV infected pregnant women and their infants in Rio de Janeiro, Brazil.

OBJECTIVES: To evaluate the safety and feasibility of zidovudine and lamivudine (AZT/3TC) given to HIV infected pregnant women and their infants in Rio de Janeiro, Brazil.
METHODS: This open label phase II study enrolled 40 HIV infected antiretroviral naive women >or=20 weeks gestation, CD4 <500 cells x10(6)/l, from two public hospitals. TREATMENT: fixed dose AZT 300 mg/3TC 150 mg by mouth every 12 hours until labour; AZT 300 mg by mouth every 3 hours until delivery; infants: AZT 4 mg/kg every 12 hours plus 3TC 2 mg/kg every 12 hours for 6 weeks. Blood haematology and chemistry were monitored; adherence evaluated by pills count; efficacy measured by changes in lymphocyte (CD4) and viral load, and by HIV RNA-PCR tests performed at birth, 6 and 12 weeks, to diagnose infant infection. No women breast fed. PATIENT CHARACTERISTICS: mean age 24.48 (SD 3.5) years; gestational age 24.5 (4.5) weeks; AZT/3TC duration 14.4 (4.4) weeks; vaginal delivery: 11/39; caesarean section: 28/39. Entry and pre-labour CD4: 310/486 cells x10(6)/l (p<0.001); entry and pre-labour viral load: 53 818/2616 copies/ml (p<0.001). Thirty nine women tolerated treatment with >80% adherence; one was lost to follow up. Five newborns were excluded from 3TC receipt. All 39 babies were uninfected. Haematological toxicity in newborns was common: anaemia in 27; neutropenia in five (two severe); platelets counts <100000 in two. All values recovered on study completion.
CONCLUSIONS: Fixed dose AZT/3TC is well accepted, gives improvements in CD4 and viral load; no infants were HIV infected. Haematological toxicity in infants needs careful monitoring.