Encephalopathies clinical trials

A Study of Azidothymidine in HIV-Infected Children

AMENDED 07/07/93: To evaluate whether continuous infusion AZT will impact neurodevelopmental deficits associated with HIV infection or alter rate of encephalopathy progression in children who have failed to improve or shown progression of these deficits despite optimal AZT therapy. AMENDED: To assess whether didanosine (ddI) will be better tolerated than AZT administered by either continuous intravenous delivery or oral administration (ddI arm removed per amended version).To determine whether ddI will achieve comparable clinical efficacy as the continuous intravenous route of delivery of AZT, and to assess whether either or both of these regimens are superior to that achieved with an intermittent AZT dosage schedule. To determine whether there are differences in patient or parent (guardian) compliance between the three treatment regimens. Original design: To determine whether the pharmacokinetic profile (bloodstream levels) of zidovudine (AZT) influences its effectiveness on HIV infection in children. That is, the study seeks to find out whether there is a difference in the effect of AZT when given as a continuous intravenous infusion (and, if available, an oral sustained release dose) compared to an intermittent (not continuous) dose given orally every 6 hours. The study also plans to determine (1) whether there are differences in the tolerance and side effects associated with AZT when given on an intermittent schedule as opposed to a steady-state schedule; (2) the extent of variation from patient to patient in AZT levels and whether the plasma and cerebrospinal fluid levels of AZT are related to the degree of therapeutic effectiveness; and (3) whether there are differences in the response of children who acquired HIV infection perinatally (just before, during, or just after the time of birth) versus those who acquired HIV infection by transfusion. One of the most serious effects of HIV disease in children is neuropsychological deterioration (relating to mental and nervous system functioning). This complication affects the vast majority of HIV infected children. A previous study of continuous intravenous administration of AZT in pediatric patients with HIV infection showed consistent and dramatic improvements of symptoms in all patients that had shown neurodevelopmental deficits or abnormalities. These improvements were seen within 3 to 4 weeks after AZT treatment was started. Neurodevelopmental improvements have been sustained on AZT, usually showing steady improvement which, in some patients, was associated with restoration of pre-HIV intellectual and neurological function. This study also showed an increase in the IQ scores of children receiving continuous infusion of AZT who did not have overt clinical evidence of encephalopathy (disease of the brain). Thus changes in cognitive function may be among the earliest signs of AIDS encephalopathy and underscores the need to start therapies that will treat the central nervous system in patients who appear to be clinically intact. A study comparing continuous infusion to intermittent dosing of AZT showed a significant increase in IQ scores for those children receiving the continuous dose compared to those treated with the intermittent schedule. Although a portable infusion pump allows patients to receive continuous infusion of AZT, a sustained release oral formulation that could provide a continuous release of AZT into the bloodstream would be highly desirable.