Mechanism of action
Erythrityltet nitrates cause direct, nonspecific smooth muscle relaxation. This effect occurs due to production of nitric oxide which stimulates formation of cGMP in the smooth muscle cells. Repeated frequent administration of high dose of erythrityl nitrates lead to decrease in magnitude of most of their pharmacological actions. Erythrityl Nitrates cause more venodilatation than arteriolar dilatation. Hence pre-load and diastolic pressure is reduced which leads to decreased cardiac work.