The efficacy and toxicity of oral
azidothymidine has been studied in 145 patients with the
acquired immunodeficiency syndrome (
AIDS) or
AIDS-related complex (
ARC). The median survival time of
AIDS patients on
azidothymidine was 4.5 times higher when compared to a historical
AIDS group who had not received the
drug. This result must be interpreted with caution because of changes in treatment of
HIV infection and growing awareness of
AIDS which may have led to earlier diagnosis in the group treated with
azidothymidine. The mortality was significantly higher in those patients who received transfusions and was particularly high in those who were transfused before
azidothymidine. There was a significant difference in the occurrence of
opportunistic infections in the patients who received transfusions compared with those who did not.
AIDS patients treated immediately after an episode of
Pneumocystis carinii pneumonia survived significantly longer than those in whom treatment was delayed for three months or more, and longer than those who were treated with
azidothymidine because of another
opportunistic infection or
Kaposi's sarcoma. The T4 cell median counts increased in patients treated with
azidothymidine reaching a peak at the end of the fourth month of treatment in the
ARC group and at the end of the first month in the
AIDS group with a subsequent fall in both groups. Sixty per cent of patients were p24
viral antigen positive at the start of treatment and 19 per cent of these patients had a fall of more than 50 per cent in
antigen level while 32 per cent became
antigen negative following treatment with
azidothymidine. The mortality in the patients where the
antigen disappeared or in whom there was a major fall of more than 50 per cent in
antigen level was significantly less than in those where there was no change in
antigen level. Twenty-nine patients were treated with
azidothymidine because of skin
Kaposi's sarcoma and in 17 tumour regressed or was stable. Thirty-two per cent of patients treated with
azidothymidine became anaemic.
Neutropenia occurred in 3 per cent of patients. Platelets increased initially
after treatment but subsequently fell to thrombocytopenic levels in eight patients. Nine of 12 patients with
thrombocytopenia before
azidothymidine was commenced responded with an increased platelet count.