Enalapril " Convertin

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Enalapril " Convertin ' :
Trade names: Enalaprilat, Convertin

Drug classes

· Antihypertensive
· ACE inhibitor
Pregnancy: (Category C/ D if used in the 2nd or 3rd trimesters.]

Therapeutic actions

Renin, synthesized by the kidneys, is released into the circulation where it acts on a plasma precursor to produce angiotensin I, which is converted by angiotensin-converting enzyme to angiotensin II, a potent vasoconstrictor that also causes release of aldosterone from the adrenals; both of these actions increase BP. Enalapril blocks the conversion of angiotensin I to angiotensin II, decreasing BP, decreasing aldosterone secretion, slightly increasing serum K+ levels, and causing Na+ and fluid loss; increased prostaglandin synthesis also may be involved in the antihypertensive action.

Indications

• Treatment of hypertension alone or in combination with thiazide-type diuretics
• Treatment of acute and chronic CHF
• Treatment of asymptomatic left ventricular dysfunction (LVD)
• Treatment of acute hypertension--IV

Contraindications/cautions

• Contraindication: allergy to enalapril.
• Use cautiously with impaired renal function; salt/volume depletion--hypotension may occur; lactation

Dose
§ Hypertension, used alone, initially 5 mg once daily;
§ if used in addition to diuretic, in elderly patients, or in renal impairment, initially 2.5 mg daily;
§ Usual maintenance dose 10–20 mg once daily;
§ In severe hypertension may be increased to max. 40 mg once daily
§ Heart failure (adjunct), asymptomatic left ventricular dysfunction, initially 2.5 mg daily under close medical supervision; usual maintenance dose 20 mg daily in 1–2 divided doses
Adverse effects

• CNS: Headache, dizziness, fatigue, insomnia, paresthesias
• GI: Gastric irritation, nausea, vomiting, diarrhea, abdominal pain, dyspepsia, elevated liver enzymes
• CV: Syncope, chest pain, palpitations, hypotension in salt/volume depleted patients
• Hematologic: Decreased hematocrit and hemoglobin
• GU: Proteinuria, renal insufficiency, renal failure, polyuria, oliguria, urinary frequency, impotence
• Other: Cough, muscle cramps, hyperhidrosis

Clinically important interactions

• Drug-drug
  • Decreased hypotensive effect if taken concurrently with indomethacin, rifampin

Nursing Considerations

• If pt undergoes any types of surgery alert surgeon and mark patient's chart with notice that enalapril is being taken; the angiotensin II formation subsequent to compensatory renin release during surgery will be blocked; hypotension may be reversed with volume expansion.
• Monitor patients on diuretic therapy for excessive hypotension following the first few doses of enalapril.
• Monitor patient closely in any situation that may lead to a fall in BP secondary to reduced fluid volume (excessive perspiration and dehydration, vomiting, diarrhea) because excessive hypotension may occur.
• Arrange for reduced dosage in patients with impaired renal function.

Monitor patient carefully because peak effect may not be seen for 4 h. Do not administer second dose until checking BP.