Cilazapril is an angiotensin-converting enzyme competitive inhibitor that binds to the same active site as angiotensin I. Cilazapril is a prodrug which is converted to its active form by the liver after being oral ingested, it then becomes its main metabolite Cilazaprilat. Cilazapril is used to treat hypertension and heart failure as it reduces the effects of angiotensin II which decreases resistance and blood pressure, as angiotensin II is a potent vasoconstrictor. Angiotensin II is produced by angiotensin-converting enzyme converting angiotensin I to angiotensin II. Angiotensin II acts on the kidneys, blood vessels, posterior pituitary gland and excitatory amino acid transporter via attaching to the Type-1 angiotensin II receptor. The kidney responds by increasing aldosterone secretion which is responsible for water and sodium uptake via the distal tubule and collecting duct. The posterior pituitary gland reacts by increasing vasopressin release, vasopressin acts on the collecting ducts to increase water reabsorption. Blood vessels react by vasoconstricting, and the excitatory amino acid transporter is inhibited and therefore does not take up L-glutamic acid into the astrocytes leaving them to interact with the NMDA receptors on the paraventricular nucleus neuron (PVN neuron) to elicit a thirst sensation, in order to encourage the body to drink more water. All of these effects together leads to increased blood pressure and resistance throughout the body which is detrimental to someone with hypertension or heart failure as it makes it more difficult for blood to circulate throughout the body. Cilazapril inhibits angiotensin II thus inhibiting its downstream effects as well, reducing aldosterone and vasopressin secretion, inhibiting vasoconstriction, and allowing the amino acid transporter to be activated. The amino acid transporter being activated means the astrocytes uptake L-glutamic acid, reducing its interaction with the PVN neuron and thus reduce thirst response. All of these in combination ultimately reduces blood pressure and resistance in the blood vessels, treating the patients for their increased blood pressure. Some adverse effects may include hypotension, hyperkalaemia, and hyponatraemia. This is due to the decreased blood pressure, decreased uptake of sodium and insufficient potassium excretion due to reduced aldosterone levels. Cilazapril is eliminated by the kidneys and excreted through urination.

Cilazapril ACE inhibitor Pathway References