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Enalaprilat injection has been studied with only one other antihypertensive agent, furosemide, which showed approximately additive effects on blood pressure. Enalapril, the pro-drug of enalaprilat, has been used extensively with a variety of other antihypertensive agents, without apparent difficulty except for occasional hypotension.
In using enalaprilat injection, consideration should be given to the fact that another angiotensin converting enzyme inhibitor, captopril, has caused agranulocytosis, particularly in patients with renal impairment or collagen vascular disease, and that available data are insufficient to show that enalaprilat injection does not have a similar risk. (See WARNINGS.)
In considering use of enalaprilat injection, it should be noted that in controlled clinical trials ACE inhibitors have an effect on blood pressure that is less in black patients than in non-blacks. In addition, it should be noted that black patients receiving ACE inhibitors have been reported to have a higher incidence of angioedema compared to non-blacks. (See WARNINGS, Angioedema.)
DOSAGE AND ADMINISTRATION
For Intravenous Administration Only
The dose in hypertension is 1.25 mg every six hours administered intravenously over a five minute period. A clinical response is usually seen within 15 minutes. Peak effects after the first dose may not occur for up to four hours after dosing. The peak effects of the second and subsequent doses may exceed those of the first.
No dosage regimen for enalaprilat injection has been clearly demonstrated to be more effective in treating hypertension than 1.25 mg every six hours. However, in controlled clinical studies in hypertension, doses as high as 5 mg every six hours were well tolerated for up to 36 hours. There has been inadequate experience with doses greater than 20 mg per day.
In studies of patients with hypertension, enalaprilat injection has not been administered for periods longer than 48 hours. In other studies, patients have received enalaprilat injection for as long as seven days.
The dose for patients being converted to enalaprilat injection from oral therapy for hypertension with enalapril maleate is 1.25 mg every six hours. For conversion from intravenous to oral therapy, the recommended initial dose of oral enalapril maleate is 5 mg once a day with subsequent dosage adjustments as necessary.
Patients on Diuretic Therapy
For patients on diuretic therapy the recommended starting dose for hypertension is 0.625 mg administered intravenously over a five minute period; also see below, Patients at Risk of Excessive Hypotension.A clinical response is usually seen within 15 minutes. Peak effects after the first dose may not occur for up to four hours after dosing, although most of the effect is usually apparent within the first hour. If after one hour there is an inadequate clinical response, the 0.625 mg dose may be repeated. Additional doses of 1.25 mg may be administered at six hour intervals.
For conversion from intravenous to oral therapy, the recommended initial dose of oral enalapril maleate for patients who have responded to 0.625 mg of enalaprilat injection every six hours is 2.5 mg once a day with subsequent dosage adjustment as necessary.
Dosage Adjustment in Renal Impairment
The usual dose of 1.25 mg of enalaprilat injection every six hours is recommended for patients with a creatinine clearance > 30 mL/min (serum creatinine of up to approximately 3 mg/dL). For patients with creatinine clearance ≤ 30 mL/min (serum creatinine ≥ 3 mg/dL), the initial dose is 0.625 mg. (See WARNINGS.)
If after one hour there is an inadequate clinical response, the 0.625 mg dose may be repeated. Additional doses of 1.25 mg may be administered at six hour intervals.
For dialysis patients, see below, Patients at Risk of Excessive Hypotension.
For conversion from intravenous to oral therapy, the recommended initial dose of oral enalapril maleate is 5 mg once a day for patients with creatinine clearance > 30 mL/ min and 2.5 mg once daily for patients with creatinine clearance ≤ 30 mL/min. Dosage should then be adjusted according to blood pressure response.
Patients at Risk of Excessive Hypotension
Hypertensive patients at risk of excessive hypotension include those with the following concurrent conditions or characteristics: heart failure, hyponatremia, high dose diuretic therapy, recent intensive diuresis or increase in diuretic dose, renal dialysis, or severe volume and/or salt depletion of any etiology (see WARNINGS). Single doses of enalaprilat injection as low as 0.2 mg have produced excessive hypotension in normotensive patients with these diagnoses. Because of the potential for an extreme hypotensive response in these patients, therapy should be started under very close medical supervision. The starting dose should be no greater than 0.625 mg administered intravenously over a period of no less than five minutes and preferably longer (up to one hour).
Patients should be followed closely whenever the dose of enalaprilat injection is adjusted and/or diuretic is increased.
Enalaprilat injection should be administered as a slow intravenous infusion, as indicated above. It may be administered as provided or diluted with up to 50 mL of a compatible diluent.
Compatibility and Stability
Enalaprilat injection as supplied and mixed with the following intravenous diluents has
been found to maintain full activity for 24 hours at room temperature:
5 percent Dextrose Injection
0.9 percent Sodium Chloride Injection
0.9 percent Sodium Chloride Injection in 5 percent Dextrose
5 percent Dextrose in Lactated Ringer's Injection
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to use whenever solution and container permit.
Enalaprilat Injection, 1.25 mg per mL, is a clear, colorless solution and is supplied in vials containing 1 mL and 2 mL.
NDC 55390-010-10, 1 mL vial, carton of 10.
NDC 55390-011-10, 2 mL vial, carton of 10.
Store below 30°C (86°F).
Manufactured by: Ben Venue Laboratories, Inc. Bedford, OH 44146. Manufactured for: Bedford Laboratories™Bedford, OH 44146. June 2005. FDA Rev date: 11/25/2002
Last reviewed on RxList: 9/19/2007
This monograph has been modified to include the generic and brand name in many instances.
Additional Enalaprilat Injection Information
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