Enalapril precautions
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
List of precautions
General
Information for Patients
Drug Interactions
Carcinogenesis, Mutagenesis, Impairment of Fertility
Pregnancy
Nursing Mothers
Pediatric Use
General
Aortic Stenosis / Hypertrophic Cardiomyopathy: As with all vasodilators, Enalapril maleate should be given with caution to patients with obstruction in the outflow tract of the left ventricle.
Impaired Renal Function: As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function may be anticipated in susceptible individuals. In patients with severe heart failure whose renal function may depend on the activity of the renin-angiotensin-aldosterone system, treatment with angiotensin converting enzyme inhibitors, including Enalapril maleate, may be associated with oliguria and/or progressive azotemia and rarely with acute renal failure and/or death.
In clinical studies in hypertensive patients with unilateral or bilateral renal artery stenosis, increases in blood urea nitrogen and serum creatinine were observed in 20 percent of patients. These increases were almost always reversible upon discontinuation of Enalapril maleate and/or diuretic therapy. In such patients renal function should be monitored during the first few weeks of therapy.
Some patients with hypertension or heart failure with no apparent pre-existing renal vascular disease have developed increases in blood urea nitrogen and serum creatinine, usually minor and transient, especially when Enalapril maleate has been given concomitantly with a diuretic. This is more likely to occur in patients with pre-existing renal impairment. Dosage reduction and/or discontinuation of the diuretic and/or Enalapril maleate may be required.
Evaluation of patients with hypertension or heart failure should always include assessment of renal function.
Hyperkalemia: Elevated serum potassium (greater than 5.7 mEq/L) was observed in approximately one percent of hypertensive patients in clinical trials. In most cases these were isolated values which resolved despite continued therapy. Hyperkalemia was a cause of discontinuation of therapy in 0.28 percent of hypertensive patients. In clinical trials in heart failure, hyperkalemia was observed in 3.8 percent of patients but was not a cause for discontinuation.
Risk factors for the development of hyperkalemia include renal insufficiency, diabetes mellitus, and the concomitant use of potassium-sparing diuretics, potassium supplements and/or potassium-containing salt substitutes, which should be used cautiously, if at all, with Enalapril maleate.
Presumably due to the inhibition of the degradation of endogenous bradykinin, persistent nonproductive cough has been reported with all ACE inhibitors, always resolving after discontinuation of therapy. ACE inhibitor-induced cough should be considered in the differential diagnosis of cough
Surgery / Anesthesia: In patients undergoing major surgery or during anesthesia with agents that produce hypotension, Enalapril maleate may block angiotensin II formation secondary to compensatory renin release. If hypotension occurs and is considered to be due to this mechanism, it can be corrected by volume expansion.
Information for Patients
Angioedema: Angioedema, including laryngeal edema, may occur at any time during treatment with angiotensin converting enzyme inhibitors, including Enalapril maleate. Patients should be so advised and told to report immediately any sign or symptoms suggesting angioedema (swelling of face, extremities, eyes, lips, tongue, difficulty in swallowing or breathing) and to take no more drug until they have consulted with the prescribing physician.
Hypotension: Patients should be cautioned to report lightheadedness, especially during the first few days of therapy. If actual syncope occurs, the patients should be told to discontinue the drug until they have consulted with the prescribing physician.
All patients should be cautioned that excessive perspiration and dehydration may lead to an excessive fall in blood pressure because of reduction in fluid volume. Other causes of volume depletion such as vomiting or diarrhea may also lead to a fall in blood pressure; patients should be advised to consult with the physician.
Hyperkalemia: Patients should be told not to use salt substitutes containing 'potassium" without consulting their physician.
Neutropenia Patients should be told to report promptly any indication of infection (e.g., sore throat, fever) which may be a sign of neutropenia.
Pregnancy: Female patients of childbearing age should be told about the consequences of exposure to ACE inhibitors. These patients should be asked to report pregnancies to their physicians as soon as possible.
NOTE: As with many other drugs, certain advice to patients being treated with Enalapril maleate is warranted. This information is intended to aid in the safe and effective use of this medication. It is not a disclosure of all possible adverse or intended effects.
Drug Interactions
Hypotension - Patients on Diuretic Therapy: Patients on diuretics and especially those in whom diuretic therapy was recently instituted, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with Enalapril maleate. The possibility of hypotensive effects with Enalapril maleate can be minimized by either discontinuing the diuretic or increasing the salt intake prior to initiation of treatment with Enalapril maleate. If it is necessary to continue the diuretic, provide close medical supervision after the initial dose for at least two hours and until blood pressure has stabilized for at least an additional hour.
Agents Causing Renin Release: The antihypertensive effect of Enalapril maleate is augmented by antihypertensive agents that cause renin release (e.g., diuretics). Non-steroidal Anti-inflammatory Agents: In some patients with compromised renal function who are being treated with non-steroidal anti-inflammatory drugs, the co-administration of Enalapril maleate may result in a further deterioration of renal function. These effects are usually reversible.
In a clinical pharmacology study, indomethacin or sulindac was administered to hypertensive patients receiving Enalapril maleate. In this study there was no evidence of a blunting of the antihypertensive action of Enalapril maleate. However, reports suggest that NSAIDs may diminish the antihypertensive effect of ACE inhibitors. This interaction should be given consideration in patients taking NSAIDs concomitantly with ACE inhibitors.
Other Cardiovascular Agents: Enalapril maleate has been used concomitantly with beta adrenergic-blocking agents, methyldopa, nitrates, calcium-blocking agents, hydralazine, prazosin and digoxin without evidence of clinically significant adverse interactions.
Agents Increasing Serum Potassium: Enalapril maleate attenuates potassium loss caused by thiazide-type diuretics. Potassium-sparing diuretics (e.g., spironolactone, triamterene, or amiloride), potassium supplements, or potassium-containing salt substitutes may lead to significant increases in serum potassium. Therefore, if concomitant use of these agents is indicated because of demonstrated hypokalemia, they should be used with caution and with frequent monitoring of serum potassium. Potassium sparing agents should generally not be used in patients with heart failure receiving Enalapril maleate.
Lithium: Lithium toxicity has been reported in patients receiving lithium concomitantly with drugs which cause elimination of sodium, including ACE inhibitors. A few cases of lithium toxicity have been reported in patients receiving concomitant Enalapril maleate and lithium and were reversible upon discontinuation of both drugs. It is recommended that serum lithium levels be monitored frequently if Enalapril maleate is administered concomitantly with lithium.
Carcinogenesis, Mutagenesis, Impairment of Fertility
There was no evidence of a tumorigenic effect when Enalapril maleate was administered for 106 weeks to male and female rats at doses up to 90 mg/kg/day or for 94 weeks to male and female mice at doses up to 90 and 180 mg/kg/day, respectively. These doses are 26 times (in rats and female mice) and 13 times (in male mice) the maximum recommended human daily dose (MRHDD) when compared on a body surface area basis.
Neither Enalapril maleate nor the active diacid was mutagenic in the Ames microbial mutagen test with or without metabolic activation. Enalapril maleate was also negative in the following genotoxicity studies: rec-assay, reverse mutation assay with E. coli, sister chromatid exchange with cultured mammalian cells, and the micronucleus test with mice, as well as in an in vivo cytogenic study using mouse bone marrow.
There were no adverse effects on reproductive performance of male and female rats treated with up to 90 mg/kg/day of Enalapril maleate (26 times the MRHDD when compared on a body surface area basis).
Pregnancy
Pregnancy Categories C (first trimester) and D (second and third trimesters).
Nursing Mothers
Enalapril maleate and Enalaprilat have been detected in human breast milk. Because of the potential for serious adverse reactions in nursing infants from Enalapril maleate, a decision should be made whether to discontinue nursing or to discontinue Enalapril maleate, taking into account the importance of the drug to the mother.
Pediatric Use
Antihypertensive effects of Enalapril have been established in hypertensive pediatric patients age 1 month to 16 years. Use of Enalapril in these age groups is supported by evidence from adequate and well-controlled studies of Enalapril in pediatric and adult patients as well as by published literature in pediatric patients.
Enalapril is not recommended in neonates and in pediatric patients with glomerular filtration rate <30 mL/min/1.73 m2, as no data are available.
Adapted from the FDA Package Insert.