Bolus and continuous infusion of tolazoline in neonates with hypoxemia.

We randomly assigned 24 neonates with hypoxemia to receive tolazoline hydrochloride. Thirteen received a single dose (SD) of 2 mg/kg intravenously, and 11 received a SD of 2 mg/kg plus a 2 mg/kg/h intravenous infusion (SDI). Increase in PaO2 greater than or equal to 15 mm Hg within 20 min of administration was more common in SDI patients. Hypotension and gastrointestinal bleeding occurred more often in SDI patients. Survival could not be related to the method of administration or initial relief of hypoxemia with tolazoline.