Nitrate-induced orthostatic hypotension and long-term circulatory adaptation.

Acute and initial treatment with ISDN provokes arterial hypotension and orthostatic dysregulation which may persist over a period of 10 h. Collapse as a potential risk has to be taken into account in the initial phase of nitrate therapy. During chronic medication, nitrate-induced drop in arterial blood pressure and orthostatic hypotension cannot longer be seen even after high-dose application of ISDN. From a therapeutic point of view these results indicate adaptation of blood pressure regulation to chronic nitrate therapy which is unrelated to potential tolerance in the venous system.