Enalapril " Convertin : Commonly used drugs in Emergency & ICU

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 angiotensinconverting 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.

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