Patient/caregiver was instructed upon and mechanism of action of clonidine as follows:
- Norepinephrine stimulates the alpha-1 receptors in the peripheral arteries, resulting in constriction or narrowing of blood vessels. Narrowing of the blood vessels result in increased peripheral resistance and blood pressure.
- Alpha-2 receptors are located in the medulla of brain and in the smooth muscle of peripheral arteries.
- Clonidine is an alpha-2 receptor agonist, which mainly stimulates these receptors located in the brain and also partially stimulates these receptors in the peripheral arteries.
- Stimulation of alpha-2 receptors in the brain result in reduced norepinephrine release, consequently leading to reduced stimulation of alpha-1 receptors by norepinephrine. Stimulation of alpha-2 receptors in the peripheral arteries result in reduced vasoconstriction and improved patency of blood vessels.
- These effects, secondary to clonidine use, leads to reduced blood vessel narrowing and peripheral resistance, and lowering of heart rate, thus contributing to lowering of blood pressure.
- By lowering the blood pressure, clonidine contributes to reduced work load on the heart and helps improve blood supply to the end organs, such as, heart, brain, and kidney.
- Thus, clonidine helps with reducing the risk for heart attack and stroke. Clonidine, by reducing the blood pressure in the renal circulation and improving blood supply to the kidneys, also slows down the progression of renal failure in individuals with compromised renal function.
