- Tablets: 1 mg, 2.5 mg, 5 mg, 10 mg, 20 mg
- Tablets: 2.5 mg, 5 mg, 10 mg *Note: human-labeled product is not available in the 1 mg tablet.
- Injectable: Enalaprilat only available for IV use.
An ACE (angiotensin-converting enzyme) inhibitor. Enalapril is converted in the liver to enalaprilat. Both enalapril maleate and enalaprilat are structurally related to captopril. It has a slow onset of action, but is of longer duration.
Enalapril/enalaprilat reduces vasoconstriction causing a decrease in peripheral resistance, a decrease in pulmonary vascular resistance and right atrial pressure in the heart. It increases cardiac output, and stroke volume. It has the ability to decrease heart rate. It also has the ability to increase renal blood flow, which may help to preserve renal function by decreasing proteinuria in animals with glomerular disease (Plumb, 2008).
Enalapril is absorbed well orally. However, enalaprilat has poor oral absorption and is best given by IV. They are both poorly distributed into the central nervous system, but do cross the placental barrier. Both forms are excreted in urine and feces.
Used in CHF (congestive heart failure), also used with caution in PGN (progressive glomerulonephroses) when hypertension is thought to be a factor.
Drug Interactions or Contraindications
- Use of NSAIDs with enalapril may reduce its efficacy.
- Use with caution where azotemia is present.
- Potential for increased hypotensive effects when used in conjunction with diuretics (e.g., Lasix) or other vasodilators (see Considerations).
CV: hypotension; disturbances in heart rhythm
CNS: sleep disturbances
Renal: May cause transient increase in BUN and creatinine levels
Blood: neutropenia, agranulocytosis
As a vasodilator and adjunctive therapy in heart failure, or in chronic kidney disease to reduce hypertension and decrease high levels of protein in urine:
Initial dose 0.5 mg/kg, PO, BID (may be titrated up based on veterinary discretion to the rat’s response) 12
0.25 mg/lb, PO, BID 3, 12
0.5 mg/kg to 1 mg/kg, PO, q24hr 34, 35, 41, 42
- Monitor weight. Report weight gain or increased edema to veterinarian.
- Avoid high sodium, high potassium foods.
- While using a diuretic (e.g., Lasix), and/or another vasodilator, in conjunction with enalapril can be helpful in heart failure do so with caution due to the potential for increased effect of hypotension.
- Reports of high doses in rodents may cause maternal and fetal death.
- Store tablets in tightly closed container at room temperature. Stable for 30 months.