Home Drug Guide Amlodipine Benzoate

Drug Guide

Generic Name

Amlodipine Benzoate

Brand Names Katerzia

Classification

Therapeutic: Antihypertensive, Antianginal

Pharmacological: Calcium Channel Blocker

FDA Approved Indications

Hypertension
Chronic Stable Angina pectoris
Vasospastic Angina (Prinzmetal's or variant angina)

Mechanism of Action

Amlodipine inhibits calcium ion influx across cell membranes of vascular smooth muscle and cardiac muscle, producing vasodilation and consequent decrease in blood pressure and angina relief.

Dosage and Administration

Adult: Initially 5 mg once daily. Dose may be increased to a maximum of 10 mg once daily, based on response.

Pediatric: Safety and efficacy not established in pediatric patients.

Geriatric: Start at lower end of dose; closely monitor for hypotension and adverse reactions.

Renal Impairment: Use with caution; no specific dosage recommendation but monitor closely.

Hepatic Impairment: Start with lower dose; monitor closely.

Pharmacokinetics

Absorption: Well-absorbed orally with no significant first-pass metabolism.

Distribution: Widely distributed; protein binding approximately 93%.

Metabolism: Primarily hepatic via CYP3A4; active metabolites are not significant.

Excretion: Excreted mainly via urine and feces; approximately 60% in urine and 40% in feces.

Half Life: Long half-life, approximately 30-50 hours, allowing once-daily dosing.

Contraindications

Hypersensitivity to amlodipine or other dihydropyridines.
Severe aortic stenosis.

Precautions

Use cautiously in patients with hypotension, congestive heart failure, or severe hepatic impairment. Pregnancy category C; use only if clearly needed. Lactation: may pass into breast milk, weigh risks and benefits.

Adverse Reactions - Common

Edema (peripheral swelling) (Common)
Headache (Common)
Dizziness (Common)
Fatigue (Common)

Adverse Reactions - Serious

Hypotension (Rare)
Severe arrhythmias or conduction disturbances (Rare)
Allergic reactions (rash, angioedema) (Rare)

Drug-Drug Interactions

Simvastatin (risk of increased statin levels)
Beta-blockers (additive effect on blood pressure)
Grapefruit juice (may increase levels)

Drug-Food Interactions

Grapefruit juice

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure and heart rate regularly. Assess for signs of edema, headache, and dizziness.

Diagnoses:

Risk for hypotension.
Ineffective peripheral tissue perfusion.

Implementation: Administer once daily, with or without food. Educate patient on avoiding sudden position changes to prevent orthostatic hypotension. Monitor for signs of swelling or adverse reactions.

Evaluation: Effective control of blood pressure and angina symptoms without adverse effects.

Patient/Family Teaching

Take medication exactly as prescribed.
Do not discontinue abruptly without consulting healthcare provider.
Report swelling, severe dizziness, or chest pain.
Limit grapefruit juice intake.

Special Considerations

Black Box Warnings:

None currently.

Genetic Factors: Variability in CYP3A4 activity may affect drug levels.

Lab Test Interference: May affect certain laboratory measurements of calcium.

Overdose Management

Signs/Symptoms: Severe hypotension, tachycardia or bradycardia, dizziness, fainting.

Treatment: Supportive measures: monitor cardiac and respiratory status, administer intravenous fluids, vasopressors if needed, gastric lavage or activated charcoal may be considered.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F). Keep container tightly closed.

Stability: Stable under recommended storage conditions.