NITRATES CAUSE DIRECT NON-SPECIFIC SMOOTH MUSCLE RELAXATION. THIS EFFECT OCCURS DUE TO PRODUCTION OF NITRIC OXIDE WHICH STIMULATES FORMATION OF CGMP IN THE SMOOTH MUSCLE CELLS WHICH LEADS TO DEPHOSPHORYLATION OF MYOSIN LIGHT CHAIN RESULTING IN SMOOTH MUSCLE RELAXATIONS, REPEATED, FREQUENT ADMINISTRATION OF HIGH DOSE TO DECREASE IN MAGNITUDE OF MOST OF THEIR PHARMACOLOGICAL ACTIONS. NITRATES CAUSE MORE VENODILATATION, HENCE PRE-LOAD AND DIASTOLIC PRESSURE IS REDUCED WHICH LEADS TO DECREASED CARDIAC WORK.