Abstract
The effect of Tz in treatment of PFC was evaluated in 14 neonates (gestational age (GA) ≤ 34 weeks, n=6) receiving maximal assisted ventilation. Intravenous Tz was administered as a loading dose of 1 to 2 mg/kg followed by a continuous intravenous infusion of 1 mg/kg/hr. The dose was increased up to 4 mg/kg/hr based on the patients clinical response. Clinical status, laboratory parameters and Tz serum concentrations were monitored throughout therapy. A positive response to Tz was observed in 70% of the patients. A curvilinear relationship was noted between Tz serum concentrations and PaO2/FiO2 ratio. The response to tolazoline was dependent on GA, serum concentration and arterial pH. A significant difference (p < 0.05) in the responsiveness to tolazoline was observed between neonates > 34 weeks and ≤ 34 weeks GA. In neonates > 34 weeks, positive therapeutic response was observed with arterial pH > 7.45 and Tz serum concentrations of 2-4 μg/ml. Neonates of ≤ 34 weeks GA, a positive therapeutic response was seen at serum concentration of 4.4 - 7.7 μg/ml and an arterial pH of 7.31 - 7.44. Systemic hypotension and GI bleeding were observed in 28.6% of the patients. This was related to high serum concentrations and arterial pH < 7.30. The rational use of Tz for the treatment of PFC requires careful monitoring of respiratory status, pH, blood pressure and serum Tz concentration.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chow-Tung, E., Fischer, J., Bhat, R. et al. 352 CLINICAL PHARMACOLOGY OF TOLAZOLINE (Tz) IN PERSISTENT FETAL CIRCULATION (PFC). Pediatr Res 19, 169 (1985). https://doi.org/10.1203/00006450-198504000-00382
Issue Date:
DOI: https://doi.org/10.1203/00006450-198504000-00382