From the Guidelines
The equivalent intravenous (IV) Enalapril (Vasotec) dose for a patient currently taking oral Amlodipine (Norvasc) is not directly convertible due to their different mechanisms of action, but the standard initial dose of IV Enalaprilat is 1.25 mg given over 5 minutes, as stated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1.
Key Considerations
- Amlodipine is a calcium channel blocker, while Enalaprilat is an ACE inhibitor, and these medications cannot be substituted for each other on a milligram-to-milligram basis.
- The initial dose of IV Enalaprilat is 1.25 mg over a 5-min period, which can be increased up to 5 mg every 6 h as needed to achieve the blood pressure target, according to the guideline 1.
- Dosing should be individualized based on blood pressure response and may need adjustment in patients with renal impairment.
- Close blood pressure monitoring is essential when transitioning between these medications, as they work through different physiological pathways.
Mechanism of Action
- Enalaprilat reduces blood pressure by preventing the conversion of angiotensin I to angiotensin II.
- Amlodipine blocks calcium influx into vascular smooth muscle cells.
- The clinical situation, comorbidities, and reason for switching from oral to IV therapy should guide medication selection and dosing, considering the distinct mechanisms of action of these drugs, as outlined in the guideline 1.
From the Research
Equivalent IV Enalapril Dose for Oral Amlodipine
There are no research papers to assist in answering this question, as the provided studies focus on the pharmacokinetics and pharmacodynamics of amlodipine, but do not provide information on the equivalent intravenous (IV) Enalapril (Vasotec) dose for a patient currently taking oral Amlodipine (Norvasc).
Key Points
- The studies provided examine the pharmacokinetics and pharmacodynamics of amlodipine, including its bioavailability, elimination half-life, and effects on blood pressure 2, 3, 4, 5, 6.
- None of the studies provide a direct comparison between oral amlodipine and IV enalapril, or offer guidance on converting between the two medications.
- The studies do demonstrate the efficacy of amlodipine in treating hypertension and angina pectoris, and provide information on its pharmacokinetic characteristics, but do not address the specific question of equivalent IV enalapril dosing 2, 3, 4, 5, 6.