Vidarabine therapy of varicella in immunosuppressed patients.

In order to assess further the clinical usefulness of vidarabine therapy of chicken pox, a double-blind, placebo-controlled trial was performed in immunocompromised patients. Thirty-four patients entered the trial; 19 received vidarabine and 15 the placebo. All patients had disease less than or equal to 72 hours in duration and 23 had lymphoproliferative malignancies. Both patient populations were balanced for underlying disease, preceding chemotherapy, and duration of chicken pox. No patient received zoster immune globulin. Drug therapy accelerated cessation of new vesicle formation (P = 0.015) and decreased median daily lesion counts (P = 0.06 on days 2 and 3). Fever (greater than or equal to 37.8 degrees C orally) resolved more rapidly in the drug-treated group. By day five, 70% of drug-treated subjects were afebrile in contrast to 35% of placebo recipients (P = 0.066). One drug recipient developed mild pneumonitis during the study which resolved with therapy, whereas eight placebo recipients developed varicella-related complications which led to death in two patients (P less than 0.01). These results were achieved with minimal evidence of laboratory or clinical toxicity related to drug administration. The findings indicate that vidarabine has a good therapeutic index (efficacy/toxicity) for treatment of chicken pox in immunocompromised patients when given early in the course of the infection.

Effect of intravenous flow rate and injection site on in vitro delivery of chloramphenicol succinate and in vivo kinetics.

The delivery rates of chloramphenicol succinate from a standard pediatric intravenous infusion set were studied in vitro at varying flow rates and injection sites of the infusion set. The pharmacokinetic properties of CAPS and chloramphenicol were then studied in 15 children given intravenous injections of CAPS via the infusion set at the flashball and Buretrol sites in a crossover fashion on successive days. In vitro, the actual times required for 95% delivery of CAPS from the infusion set were two- to fourfold longer than the predicted infusion times at flow rates of 5, 15, and 29 ml/min and at all three available injection sites. In vivo, flashball injections vs Buretrol injections resulted in significantly higher mean peak serum concentrations of CAPS and CAP, with peaks occurring significantly sooner after the beginning of the intravenous infusion. These results suggest a need for considering characteristics of CAPS infusion when monitoring and interpreting serum concentration values.

Reye syndrome in siblings.

Reye syndrome in siblings was seen in three of 85 families; the incidence of RS in these family groups appears to exceed that of the general population. The interval between development of RS in the first and second siblings was two to 11 days and related to the incubation period of the initial viral infection. In five of the children this infection was chickenpox and in two, an unspecified upper respiratory illness. To assess the role of genetic factors, HLA typing was performed on these siblings; a common genetic marker indicating susceptibility to RS was not identified. All families resided in rural and suburban areas; exposure to a common environmental toxin was not identified.