Drug Information for Zidovudine (State of Florida DOH Central Pharmacy): 14 CLINICAL STUDIES

  • Therapy with zidovudine has been shown to prolong survival and decrease the incidence of opportunistic infections in patients with advanced HIV-1 disease and to delay disease progression in asymptomatic HIV-1-infected patients.
  • 14.1 Adults

  • Combination Therapy:  Zidovudine in combination with other antiretroviral agents has been shown to be superior to monotherapy for one or more of the following endpoints: delaying death, delaying development of AIDS, increasing CD4+ cell counts, and decreasing plasma HIV-1 RNA.The clinical efficacy of a combination regimen that includes zidovudine was demonstrated in study ACTG320. This study was a multi-center, randomized, double-blind, placebo-controlled trial that compared zidovudine 600 mg/day plus EPIVIR® 300 mg/day to zidovudine plus EPIVIR plus indinavir 800 mg t.i.d. The incidence of AIDS-defining events or death was lower in the triple-drug–containing arm compared with the 2-drug–containing arm (6.1% versus 10.9%, respectively).Monotherapy: In controlled studies of treatment-naive patients conducted between 1986 and 1989, monotherapy with zidovudine, as compared with placebo, reduced the risk of HIV-1 disease progression, as assessed using endpoints that included the occurrence of HIV-1-related illnesses, AIDS-defining events, or death. These studies enrolled patients with advanced disease (BW002), and asymptomatic or mildly symptomatic disease in patients with CD4+ cell counts between 200 and 500 cells/mm3 (ACTG016 and ACTG019). A survival benefit for monotherapy with zidovudine was not demonstrated in the latter 2 studies. Subsequent studies showed that the clinical benefit of monotherapy with zidovudine was time limited.
  • 14.2 Pediatric Patients

  • ACTG300 was a multi-center, randomized, double-blind study that provided for comparison of EPIVIR plus zidovudine to didanosine monotherapy. A total of 471 symptomatic, HIV-1-infected therapy-naive pediatric patients were enrolled in these 2 treatment arms. The median age was 2.7 years (range 6 weeks to 14 years), the mean baseline CD4+ cell count was 868 cells/mm3, and the mean baseline plasma HIV-1 RNA was 5 log10 copies/mL. The median duration that patients remained on study was approximately 10 months. Results are summarized in Table 10.
    Table 10. Number of Patients (%) Reaching a Primary Clinical Endpoint (Disease Progression or Death)
    Endpoint EPIVIR plus Zidovudine (n = 236) Didanosine (n = 235)
    HIV disease progression or death (total) Physical growth failure Central nervous system deterioration CDC Clinical Category C Death15 (6.4%) 7 (3%) 4 (1.7%) 2 (0.8%) 2 (0.8%)37 (15.7%) 6 (2.6%) 12 (5.1%) 8 (3.4%) 11 (4.7%)
  • 14.3 Prevention of Maternal-Fetal HIV-1 Transmission

  • The utility of zidovudine for the prevention of maternal-fetal HIV-1 transmission was demonstrated in a randomized, double-blind, placebo-controlled trial (ACTG076) conducted in HIV-1-infected pregnant women with CD4+ cell counts of 200 to 1,818 cells/mm3 (median in the treated group: 560 cells/mm3) who had little or no previous exposure to zidovudine. Oral zidovudine was initiated between 14 and 34 weeks of gestation (median 11 weeks of therapy) followed by IV administration of zidovudine during labor and delivery. Following birth, neonates received oral zidovudine syrup for 6 weeks. The study showed a statistically significant difference in the incidence of HIV-1 infection in the neonates (based on viral culture from peripheral blood) between the group receiving zidovudine and the group receiving placebo. Of 363 neonates evaluated in the study, the estimated risk of HIV-1 infection was 7.8% in the group receiving zidovudine and 24.9% in the placebo group, a relative reduction intransmission risk of 68.7%. Zidovudine was well tolerated by mothers and infants. There was no difference in pregnancy-related adverse events between the treatment groups.
  • Drug Information Provided by National Library of Medicine (NLM).