What Is Captopril And What Is It Used For?

The effects of captopril and thiazide diuretics add up, so the therapeutic effect is enhanced. Better results are therefore obtained with their combination. Before starting treatment with captopril, it is essential to know the patient’s previous antihypertensive treatments.

Captopril is a drug that belongs to the family of converting enzyme inhibitors (ACEs). It works by blocking the peptidase protein of the active center of this enzyme.

ACE is an enzyme that converts angiotensin I into angiotensin II, a molecule that exhibits potent vasoconstrictor effects and subsequent increase in blood pressure, among other effects.

Captopril  was the first molecule synthesized by structural variation from the original angiotensin I molecule  and the ACE receptor. Thanks to this, it was possible to carry out other studies of structural variation on other molecules with their corresponding receptors.

Indications and dosage of captopril

As we have mentioned,  this medicine is mainly used for the treatment of hypertension. However, it is also indicated to fight other diseases. Depending on the indication, the doses and dosage will vary.

Now let’s see in more detail each of the  main indications of captopril  and the recommended doses for each of them:

Hypertension

For the treatment of this disease,  captopril can be given as monotherapy or in combination therapy  with other drugs indicated for the treatment of hypertension. It is mainly administered concomitantly with thiazide diuretics.

The effects of captopril and thiazide diuretics add up, so the therapeutic effect is enhanced. Better results are therefore obtained with their combination.

Before starting captopril treatment, it is essential to know the patient’s previous antihypertensive medication, as well as his blood pressure, salt restriction in the diet and other clinical situations.

The starting dose is 50 mg per day. However, if after two weeks the clinical picture does not improve, one can switch to 100 mg per day or 50 mg twice daily. If taken with other antihypertensive drugs, the doctor will change the dose to ensure patient safety.

Heart failure

Captopril  is also indicated for the treatment of heart failure. The majority of clinical trials have studied the effect of this drug when co-administered with other agents. However, captopril does not require the presence of concomitant drugs to be effective against this disease.

Regarding the recommended doses, in normotensive or hypotensive patients who have previously had treatment with diuretics and who may be hypovolemic and / or hyponatremic,  an initial dose of 6.25 or 12.5 mg given three times per day may minimize the magnitude or duration of the hypotensive effect.

However,  for the majority of patients with heart failure, the starting daily dose is 25 mg three times a day. One should never go beyond 450 mg per day with this medication.

Myocardial infarction

This is another indication of this ECA. More specifically, it is indicated in post-myocardial infarction, after 72 hours of hemodynamic stability in patients who have presented heart failure during the course of the disease or who have evidence of a reduced ejection fraction.

Treatment, in this case,  should begin as early as possible, from the first 72 hours after the infarction. We start with an initial dose of 6.25 mg which will then increase to 12.5 mg three times a day.

The dose may be gradually increased depending on the patient’s tolerance  to 25 mg three times a day, up to a dose of 150 mg once a day. If the patient has symptomatic hypotension, this dose should be reduced.

Diabetic nephropathy

Finally, we must mention this other indication of captopril. It is given to insulin-dependent patients who suffer from this disease. It doesn’t matter whether they are normotensive or hypertensive. The goal of treatment with captopril in these patients is to prevent the progression of kidney disease,  as well as to reduce the clinical sequelae associated with the latter.

The recommended dose varies between 75 and 100 mg per day, divided into several doses. If these doses are not sufficient to achieve the therapeutic goal, they can be combined with other drugs, such as:

• β-blockers.
• Vasodilators.
• Hypotensors.

Conclusions on captopril

Captopril  is a drug widely used to treat high blood pressure as  well as other illnesses, such as myocardial infarction or heart failure.

Because of its powerful effects, it is essential to always follow the doctor’s instructions and not to abuse this type of medication. If in doubt, you can consult your doctor or pharmacist.