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Biomedical subjects

R F Ritz

Publications and source records attributed to R F Ritz.

4 recordsLinked to original sources
PubMed1993

Acyclovir-induced neurotoxicity: concentration-side effect relationship in acyclovir overdose.

PURPOSE: To investigate the concentration-side effect relationship in a patient with severe acyclovir-induced neurotoxicity and to summarize the information available in the literature about central nervous system side effects due to acyclovir. METHODS: Repeated blood samples were drawn in a patient with severe acyclovir overdose who developed coma and nonoliguric renal failure. The acyclovir levels measured by radioimmunoassay were related to the level of consciousness. RESULTS: We measured the highest acyclovir serum levels reported so far (229.9 mumol/L = 51.8 mg/L). Impairment of consciousness developed with a remarkable temporal delay of 24 to 48 hours after occurrence of peak serum concentrations and resolved with a comparable delay after reaching the therapeutic range (anticlockwise hysteresis). Six days after discontinuation of the drug, central nervous system symptoms had resolved, and, 4 days later, renal function returned to pretreatment values. CONCLUSIONS: The observation that neurotoxicity developed with a delay of 24 to 48 hours after acyclovir peak serum concentrations could explain the wide range of acyclovir levels reported in similar cases. Single drug level measurements may therefore be of little diagnostic value. Since toxicity develops with a remarkable delay, early removal of the drug (by hemodialysis) could possibly prevent central nervous toxicity.

Acyclovir↗
PubMed1991

Timing of invasive procedures in therapy for primary and secondary spontaneous pneumothorax.

Timing of invasive procedures during chest tube therapy in spontaneous pneumothorax is undefined. Evaluation of 115 patients with primary and secondary spontaneous pneumothorax treated with tube thoracostomy revealed nearly maximal healing rates after 48 hours without a relevant increase if drainage was maintained for up to 10 days. In secondary spontaneous pneumothorax, a significantly lower healing rate was observed after 48 hours compared with primary spontaneous pneumothorax (60% vs 82%). Therapeutic success was not predictable by single clinical variables available at admission (eg, age, gender, and smoking habits) nor by their combinations. Recurrence rates were 30% in both primary and secondary spontaneous pneumothorax. Hospital stay averaged 6 days in primary and 15 days in secondary spontaneous pneumothorax. Considering their efficacy and the low incidence of complications, the early use of invasive procedures such as surgical pleurectomy, after 48 hours of persistent gas leaking, seems justified. Shorter in-patient care and lower recurrence rates may result.

Adult↗
PubMed1990

[Clinical aspects of severe digitalis poisoning and its treatment with and without digoxin-specific antibodies. 3 case reports].

Although elevated digitalis concentrations are often observed, symptomatic intoxications occur less frequently. We report the course in three patients with extremely elevated digitalis concentrations as examples of the poor correlation between measured serum levels and symptoms. In view of the cost of treatment by fab-fragments and the lack of a close dose-related effect of digitalis, we suggest restricting the use of fab-fragment therapy to patients with severe hyperkalemia or hemodynamically relevant arrhythmias.

Adult↗