Enalapril: uses and side effects

Enalapril is an ACEI drug, that is, is an angiotensin converting enzyme inhibitor. It is used for the treatment of hypertension and some types of chronic heart failure.

The Cardiovascular effects of ACEI drugs are complex and highly beneficial, both short and long term. Among them we can mention:

  • Blood pressure reduction
  • Decreased cardiac hypertrophy.
  • Decrease in arterial remodeling.

At the renal level, produce an increase in renal blood flow and a moderate long-term effect of diuresis and natriuresis.

At first, The clinical efficacy of enalapril is similar to that of the rest of the IECAS. The differences lie in the diversity of the pharmacological potency and its various pharmacokinetic characteristics.

How does enalapril produce its effects on the body?

With the ACE enzyme inhibition, the main effect is the reduction of angiotensin II production. This molecule acts as a potent peripheral vasoconstrictor and stimulates the secretion of aldosterone by the adrenal gland, which increases blood volume. Therefore, enalapril, and also the other IECAS, interfere in this process of the renin-angiotensin system.

However, the angiotensin-converting enzyme also acts on other substrates, such as bradykinin, whose levels increase. At the same time, Bradykinin increases nitric oxide and prostaglandin levels; hence all of them can contribute to the final vascular effect of the IECAS.

In addition, they interfere with negative feedback processes, so, in the long run, angiotensin I concentrations increase. Finally, since this could not become the II because the conversion enzyme was inhibited, its metabolism shifts to the production of angiotensin-1,7.

Pharmacokinetics: what happens to the drug in the body?

Pharmacokinetics encompasses the processes of absorption, distribution, metabolism and elimination through which the drug passes once administered. In this sense, vincpril is administered orally and, if necessary, intravascularly. However, being the majority oral route, we will focus on it.

After administration, maximum plasma concentrations can be observed after one hour. It has an absorption of 60% that is not affected with the presence of food in the stomach.

Once it has been absorbed, enalapril is hydrolyzed into another compound called enalaprilat, which is the true ACE inhibitor. Therefore, enalapril is a prodrug of enalaprilat, which is the molecule that will truly carry the antihypertensive action.

The excretion of enalapril is, above all, renal. This elimination process is, in good part, as an active principle, so its clearance decreases in the event that the patient suffers from renal failure.

Read also: Treatment of chronic renal failure

Adverse reactions and contraindications of enalapril

The main side effect of this drug, and in general of the IECAS, is the production of persistent dry cough, which is resistant to antitussive drugs. Enalapril stimulates the C fibers that transmit the stimuli to the cough center; In addition, the accumulation of angiotensin I causes a vasoconstriction that produces cough. This adverse reaction disappears within 4 days of withdrawing the treatment.

On the other hand, the following side effects may also appear:

  • Angioedema: boosted by the cininas, forces to suspend the treatment.
  • Hypotension: Venodilation without reflex tachycardia.
  • Hyperkalemia: due to a lower release of aldosterone.
  • Insufficiency acute renal: in patients with chronic heart failure.
  • Neutropenia: in patients with renal insufficiency.

Apart from all these adverse reactions, the patient may suffer other effects not mentioned. However, all these reactions have a very low rate of occurrence.

Pregnant women cannot take enalapril, since it affects the fetus. Nor can patients who are allergic to any component of the formulation take it.


Enalapril may interact with other drugs by increasing or reducing its effect or that of concomitant medication. Its administration with NSAIDs reduces its hypotensive effect, since the latter decrease the synthesis of prostaglandins.

Another interaction that can be given is when administered with antacids, since the latter reduce the absorption of enalapril. To avoid this interaction, it is recommended to space the shot every 2 hours. By last, also interacts with potassium-sparing diuretics. Its joint administration exacerbates the hyperkalaemia of enalapril.

Discover: Drug interactions and their impact


Enalapril is a drug subject to medical prescription indicated for the treatment of hypertension. If you are taking another medication at the time that enalapril is prescribed, you should notify the doctor in order to prevent complications.