Last reviewed 2026-04-20 · How we verify

Vasotec (enalapril)

ACE inhibitor prodrug that is converted to enalaprilat, blocking angiotensin-converting enzyme to lower blood pressure.

Enalapril (Vasotec) is a widely prescribed ACE inhibitor developed by Merck, approved in 1985. Proven to reduce mortality in heart failure. Available generically worldwide. WHO Essential Medicine.

At a glance

Mechanism of action

Enalapril was the second ACE inhibitor approved (after captopril) and the first with once-daily dosing. It is a prodrug converted to enalaprilat by hepatic esterases. The IV form (enalaprilat) is used for hypertensive emergencies. Proven to reduce mortality in heart failure (CONSENSUS and SOLVD trials).

Approved indications

• Asymptomatic left ventricular systolic dysfunction
• Congestive heart failure
• Hypertensive disorder

Boxed warnings

• WARNING: FETAL TOXICITY See full prescribing information for complete boxed warning. When pregnancy is detected, discontinue enalapril maleate as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. (See WARNINGS: Fetal Toxicity .)

Common side effects

• Dizziness
• Hypotension
• Headache
• Dizziness
• Fatigue
• Orthostatic Effects
• Syncope
• Cough
• Chest Pain
• Diarrhea
• Orthostatic Hypotension
• Asthenia

Serious adverse events

• Anaphylactoid reactions
• Cardiac arrest
• Myocardial infarction
• Cerebrovascular accident
• Pulmonary embolism and infarction
• Pulmonary edema
• Hepatic failure
• Hepatitis
• Pancreatitis
• Ileus

Key clinical trials

• Is There an Adverse Drug Reaction Between Renin-Angiotensin System Blockade and Inhaled Anesthetics? - A Pilot Study. Optional Deoxyribo-Nucleic Acid Donation for the Study of Hypertension. (Phase 4)
• NCT01015937 (NA)
• Inner Mongolia Stroke Project A Randomized Controlled Trial of Immediate Blood Pressure Reduction on Death and Major Disability in Patients With Acute Ischemic Stroke in China (NA)
• The Renin-angiotensin System (RAS) in Barrett's Esophagus as Future Biomarkers for Dysplasia and Cancer? A Randomized Controlled Trial (EARLY/Phase 1)
• The Effect of Enalapril, Losartan or Not Antihypertensive on the Oxidative Status in Renal Transplant Recipients (Phase 2)
• A Single Center, Single Arm, Phase 2, Pilot Study to Investigate the Efficacy of the ACE Inhibitor Enalapril in Participants Aged 18-70 Years of Age With Painful Venous Malformations. (Phase 2)
• Randomized Controlled Blind End Point Study of Enalapril Folic Acid Tablets Combined With Calcium Antagonist or Diuretic to Prevent Stroke in Patients With Type H Hypertension (Phase 3)
• The Effect of Aliskiren and Losartan on Peritoneal Membrane in Continuous Ambulatory Peritoneal Dialysis Patients (Phase 4)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.