Quinapril
Encyclopedia
Quinapril is an angiotensin-converting enzyme
inhibitor
(ACE inhibitor
) used in the treatment of hypertension
and congestive heart failure
.
. It is converted to its active metabolite, quinaprilat
, in the liver.
the formation of angiotensin
II from its precursor, angiotensin I. Angiotensin II is a powerful vasoconstrictor and increases blood pressure through a variety of mechanisms. Due to reduced angiotensin production, plasma concentrations of aldosterone
are also reduced, resulting in increased excretion of sodium
in the urine and increased concentrations of potassium
in the blood.
) and as adjunctive therapy in the management of heart failure. It may be used for the treatment of hypertension by itself or in combination with thiazide diuretics, and with diuretics and digoxin
for heart failure.
s of quinapril include dizziness, cough, vomiting, upset stomach, angioedema
and fatigue.
Angiotensin-converting enzyme
Angiotensin I-converting enzyme , an exopeptidase, is a circulating enzyme that participates in the body's renin-angiotensin system , which mediates extracellular volume , and arterial vasoconstriction...
inhibitor
Enzyme inhibitor
An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...
(ACE inhibitor
ACE inhibitor
ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...
) used in the treatment of hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and congestive heart failure
Congestive heart failure
Heart failure often called congestive heart failure is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition...
.
Pharmacology
Quinapril is a prodrugProdrug
A prodrug is a pharmacological substance administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite, a process termed bioactivation. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and...
. It is converted to its active metabolite, quinaprilat
Quinaprilat
Quinaprilat is the active metabolite of quinapril....
, in the liver.
Mechanism of action
Quinapril inhibits angiotensin converting enzyme, an enzyme which catalysesCatalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
the formation of angiotensin
Angiotensin
Angiotensin, a peptide hormone, causes blood vessels to constrict, and drives blood pressure up. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex...
II from its precursor, angiotensin I. Angiotensin II is a powerful vasoconstrictor and increases blood pressure through a variety of mechanisms. Due to reduced angiotensin production, plasma concentrations of aldosterone
Aldosterone
Aldosterone is a hormone that increases the reabsorption of sodium ions and water and the release of potassium in the collecting ducts and distal convoluted tubule of the kidneys' functional unit, the nephron. This increases blood volume and, therefore, increases blood pressure. Drugs that...
are also reduced, resulting in increased excretion of sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
in the urine and increased concentrations of potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
in the blood.
Indications
Quinapril is indicated for the treatment of high blood pressure (hypertensionHypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
) and as adjunctive therapy in the management of heart failure. It may be used for the treatment of hypertension by itself or in combination with thiazide diuretics, and with diuretics and digoxin
Digoxin
Digoxin INN , also known as digitalis, is a purified cardiac glycoside and extracted from the foxglove plant, Digitalis lanata. Its corresponding aglycone is digoxigenin, and its acetyl derivative is acetyldigoxin...
for heart failure.
Contraindications
- Pregnancy
- Impaired renal and liver function
- Patients with a history of angioedema related to previous treatment with an ACE inhibitor.
- Hypersensitivity to quinapril
Side effects
Side effectAdverse drug reaction
An adverse drug reaction is an expression that describes harm associated with the use of given medications at a normal dosage. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs...
s of quinapril include dizziness, cough, vomiting, upset stomach, angioedema
Angioedema
Angioedema or Quincke's edema is the rapid swelling of the dermis, subcutaneous tissue, mucosa and submucosal tissues. It is very similar to urticaria, but urticaria, commonly known as hives, occurs in the upper dermis...
and fatigue.