Metamizol acts as an ATP sensitive potassium channel opener to inhibit the contracting response induced by angiotensin II but not to norepinephrine in rat thoracic aorta smooth muscle.

Clinically metamizol (MZ) has been related to alteration on haemodynamic parameters and modifications on blood pressure in humans when administered intravenously. These effects have been observed at MZ therapeutic doses. Experimentally, MZ is able to induce relaxation on several types of vascular smooth muscles and modulates the contraction induced by phenylephrine.