Antiviral and immunological effects of escalating low doses of zidovudine in HIV-positive patients.
Twenty-eight patients with different stages of HIV infection who had not undergone antiretroviral pretreatment were treated with an escalating dose regimen of zidovudine (4 weeks 2 x 50 mg, 4 weeks 2 x 100 mg, 4 weeks 2 x 250 mg). CD4+ cell counts and p24 antigen levels were monitored every four weeks. Twenty-one patients were evaluable. p24 antigen levels showed a significant decrease after four weeks (p < 0.01, Sign test, Wilcoxon matched pairs test) that was sustained until week 12 without a further significant decrease. CD4+ cell counts increased significantly within the first four weeks (p < 0.01, Sign test, Wilcoxon matched pairs test). This increase was sustained until week 12 but no further significant increase was noted. Mean corpuscular erythrocyte volume values increased significantly after week 4 and continued to rise until week 12. These results demonstrate antiretroviral activity of a very low zidovudine dose, however low doses should not be used for treatment unless the clinical efficacy is shown to be equivalent to that of standard doses.