[The tolerance phenomenon in the therapeutic management of angina pectoris]

Tachyphylaxis in the treatment of angina pectoris may be found in widely different situations, such as stable angina turned unstable owing to local coronary changes, interference with another pathology (intricate angina) or true "escape phenomenon". In clinical practice, angina from tachyphylaxis may be due to a variety of causes, including lack of compliance (often difficult to diagnose), untimely drug administrations, insufficient dosage or habituation. Habituation corresponds to adaptation of the cells to their chemical environment. In the case of angina, it is due to gradual depletion of sulfhydryl radicals in the vascular endothelial cells. This progressive insensitivity to nitrites accounts for some therapeutic failures. Molsidomine is thought to be of great interest in such cases.