The impact of zidovudine (AZT) therapy on the survivability of those with the progressive HIV infection

An analysis of the data regarding the impact of zidovudine therapy on the Survivability of those with progressive HIV disease demonstrates that this therapy extends longevity for perhaps 5.5 months on the average but does not prevent the disease from eventually being fatal. All of the benefits of zidovudine therapy in extending survivability appear to accrue within a relatively short treatment period, perhaps within a few months, but the effectiveness of this drug wanes in time, suggesting that zidovudine therapy could eventually be stopped without influencing survivability. Since the efficacy of zidovudine therapy in extending survivability appears to be independent of the stage of the HIV infection in infecteds whose CD4 T-cell densities fall below 200 cells/mm³, zidovudine therapy should be initiated when the patient's infection reaches a potentially fatal stage. Zidovudine therapy may be viewed as causing the HIV infection to regress to a previous stage of the disease, but the infection's progression promptly resumes and follows a course similar to one uninfluenced by zidovudine.