Drug Guide
Trandolapril; Verapamil Hydrochloride
Classification
Therapeutic: Antihypertensive
Pharmacological: ACE inhibitor and calcium channel blocker
FDA Approved Indications
- Hypertension
- Chronic Stable Angina
Mechanism of Action
Trandolapril, an ACE inhibitor, reduces angiotensin II formation, lowering blood pressure and decreasing afterload. Verapamil, a calcium channel blocker, inhibits calcium influx into vascular smooth muscle and cardiac cells, leading to vasodilation and decreased heart rate.
Dosage and Administration
Adult: Typically, 2-4 mg once daily, titrated based on response.
Pediatric: Not approved for pediatric use.
Geriatric: Start at lower doses due to increased sensitivity and risk of hypotension.
Renal Impairment: Use caution; dose adjustments may be required.
Hepatic Impairment: Adjust dosage accordingly; cautious use recommended.
Pharmacokinetics
Absorption: Well absorbed after oral administration.
Distribution: Widely distributed, blood protein binding approximately 70-80%.
Metabolism: Metabolized in the liver, primarily via CYP3A4.
Excretion: Excreted mainly in urine and feces.
Half Life: Approximately 24 hours for both components.
Contraindications
- History of angioedema related to previous ACE inhibitor or calcium channel blocker therapy.
- Severe hypotension.
- Obstruction of the outflow tract from the ventricles.
- Known hypersensitivity to components.
Precautions
- Use caution in volume-depleted patients, hepatic or renal impairment, and in pregnancy (see pregnancy category).
Adverse Reactions - Common
- Dizziness (Common)
- Headache (Common)
- Hypotension (Common)
- Peripheral edema (Common)
Adverse Reactions - Serious
- Angioedema (Rare)
- Severe hypotension (Rare)
- Bradycardia or heart block with verapamil (Rare)
Drug-Drug Interactions
- Other antihypertensives, diuretics, rifampin (affects metabolism), drugs that increase risk of hyperkalemia.
Drug-Food Interactions
- Potassium-rich foods or supplements (risk of hyperkalemia).
Drug-Herb Interactions
- St. John’s Wort (may decrease effectiveness).
Nursing Implications
Assessment: Monitor blood pressure, heart rate, renal function, and serum electrolytes.
Diagnoses:
- Risk for hypotension
- Risk for electrolyte imbalance
- Ineffective peripheral tissue Perfusion
Implementation: Administer as directed, monitor vital signs regularly, check labs periodically.
Evaluation: Assess for blood pressure control, adverse effects, and symptoms of angioedema or heart failure.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Do not discontinue abruptly.
- Report signs of swelling, difficulty breathing, or chest pain.
- Limit potassium-rich foods and monitor fluid intake.
Special Considerations
Black Box Warnings:
- Fetal toxicity; discontinue as soon as pregnancy is detected.
Genetic Factors: Variability in CYP3A4 activity may affect metabolism.
Lab Test Interference: ACE inhibitors may affect renal function tests and serum potassium.
Overdose Management
Signs/Symptoms: Severe hypotension, bradycardia, AV block, or respiratory depression.
Treatment: Administer intravenous fluids, vasopressors for hypotension, atropine for bradycardia, and supportive care as needed.
Storage and Handling
Storage: Store at room temperature, 20-25°C, away from moisture and light.
Stability: Stable under recommended conditions.