[Tolerance of treatment with nitrate derivatives].

Tolerance to treatment with nitrate derivatives, suspected for many years and often ignored in everyday clinical practice, has recently been the subject of much study. Although the phenomenon has been clearly demonstrated in patients on long-term therapy, it seems to vary from patient to patient, with the underlying pathology and the galenic form of nitrate used. The mechanism of tolerance to nitrates is multifactorial, related on the one hand to depletion of sulfhydryl groups in the body and on the other to activation of the sympathetic and renin-angiotensin systems. The administration of sulfhydryl groups in the form of N-acetylcysteine partially restores the effects of nitrates in some patients.