[Development of tolerance in continuous nitroglycerin infusion].

For treatment of unstable angina pectoris or recent myocardial infarction, intravenous NTG is frequently employed, beginning with doses of 3 mg/h or more; thereafter, dependent on the clinical course, in particular, if the blood pressure is lowered notably, the dose may be reduced to 1 or 2 mg/h. Reports published in recent years have documented to the development of tolerance to nitrates when given orally in higher doses three times daily or administered by the transdermal mode. Accordingly, we suspected that tolerance development would be the inevitable outcome during a continuous intravenous infusion of NTG.