Lisinopril
Lisinopril is an **angiotensin-converting enzyme (ACE) inhibitor** used primarily as a vasodilator in veterinary medicine for the management of **congestive heart failure (CHF)** and **systemic hypertension**. Key clinical highlights: * **Directly Active**: Unlike enalapril, lisinopril is not a prodrug and does not require hepatic biotransformation to become active, which may be advantageous in patients with concurrent severe hepatic dysfunction. * **Once-Daily Dosing**: It typically offers a longer duration of action compared to some other ACE inhibitors, allowing for convenient once-daily dosing in many patients. * **Renal Protection**: Often utilized to reduce proteinuria and help preserve renal function in patients with chronic kidney disease (CKD) or protein-losing nephropathies. * **Hemodynamic Benefits**: Decreases total peripheral resistance, pulmonary vascular resistance, and pulmonary capillary wedge pressure while increasing cardiac output and exercise tolerance. > **Clinical Pearl**: While enalapril and benazepril are more commonly used and extensively studied in veterinary medicine, lisinopril serves as a viable, often less expensive alternative, particularly when once-daily dosing is preferred.
Mecanismo: Lisinopril exerts its effects by interfering with the **Renin-Angiotensin-Aldosterone System (RAAS)**. * **Mechanism**: It competitively binds to and inhibits **angiotensin-converting enzyme (ACE)**. * **Pathway**: **Angiotensin I** → (blocked by ACE inhibition) → Decreased **Angiotensin II**. * **Physiological Effects**: 1. **Vasodilation**: Reduction in Angiotensin II (a potent vasoconstrictor) leads to decreased systemic vascular resistance (afterload) and venous tone (preload). 2. **Decreased Aldosterone**: Lower Angiotensin II levels reduce the secretion of **aldosterone** from the adrenal cortex → decreased sodium and water retention. 3. **Bradykinin Preservation**: ACE is also responsible for the breakdown of bradykinin. Inhibition leads to increased bradykinin levels, contributing to vasodilation (but also potentially causing a mild cough). * **Net Result**: Decreased blood pressure, reduced cardiac workload, and decreased proteinuria due to efferent arteriolar vasodilation in the glomerulus.
Dosificación por especie
- Adjunctive treatment of heart failure · 0.25-0.5 mg/kg · PO · q24h
- Adjunctive treatment of heart failure · 0.5 mg/kg · PO · q12-24h
- Adjunctive treatment of heart failure · 0.5 mg/kg · PO · q24h
- Adjunctive treatment of heart failure · 0.25-0.5 mg/kg · PO · q24h · Highest recommended doses should be used unless not tolerated by patient.
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Known hypersensitivity to ACE inhibitors
- Pregnancy (especially 2nd and 3rd trimesters)
Efectos adversos
- Anorexia
- Vomiting
- Diarrhea
- Lethargy or weakness
- Hypotension
- Renal dysfunction (azotemia)
- Hyperkalemia
- Cough (rare in animals compared to humans)
Interacciones farmacológicas
- Antidiabetic Agents (insulin, oral agents) · Possible increased risk for hypoglycemia; enhanced monitoring recommended.
- Diuretics (e.g., furosemide, hydrochlorothiazide) · Potential for increased hypotensive effects; reducing furosemide doses (by 25-50%) is often recommended when initiating ACE inhibitors in CHF.
- Potassium-Sparing Diuretics (e.g., spironolactone, triamterene) · Increased risk of hyperkalemia; enhanced monitoring of serum potassium recommended.
- Other Hypotensive Agents · Potential for additive hypotensive effects.
- Lithium · Increased serum lithium levels possible; increased monitoring required.
- NSAIDs · May reduce the anti-hypertensive or positive hemodynamic effects of lisinopril; may increase the risk of acute renal failure.
- Potassium Supplements · Increased risk for hyperkalemia.
Monitoreo
- Clinical signs of CHF (respiratory rate/effort, exercise tolerance)
- Blood pressure (especially upon initiation or dose changes)
- Serum electrolytes (specifically potassium)
- Renal panel (BUN, Creatinine)
- Urine protein
- Periodic CBC with differential
Sobredosis
The primary concern with overdosage is **hypotension**. * **Toxicity Thresholds**: In dogs, the lowest dosage documented to cause hypotension is 27 mg/kg. Dosages below 20 mg/kg generally cause only mild signs (vomiting, lethargy). In cats, hypotension was noted at 4.9 mg/kg in a single case. In birds, mild somnolence occurred at 41 mg/kg. * **Clinical Signs**: Hypotension, lethargy, vomiting, and tachycardia. * **Treatment**: Recent overdoses should be managed using gut-emptying protocols when warranted. Supportive treatment with **volume expansion using normal saline** is recommended to correct blood pressure. Due to the drug's long duration of action, prolonged monitoring and treatment may be required.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.