Home Drug Guide Nifedipine

Drug Guide

Generic Name

Nifedipine

Brand Names Procardia, Adalat, Procardia XL, Adalat Cc, Afeditab CR

Classification

Therapeutic: Antihypertensive, Antianginal

Pharmacological: Calcium Channel Blocker

FDA Approved Indications

  • Hypertension
  • Chronic Stable Angina
  • Vasospastic Angina (Prinzmetal's Angina)

Mechanism of Action

Nifedipine inhibits the influx of calcium ions into vascular smooth muscle and cardiac muscle by blocking L-type calcium channels, resulting in vasodilation and decreased peripheral resistance.

Dosage and Administration

Adult: Initially, 30-60 mg once daily; titrate as needed up to 90-120 mg daily, administered once or in divided doses.

Pediatric: Not typically recommended for pediatric use; consult specific guidelines.

Geriatric: Start at lower doses due to increased sensitivity and risk of hypotension.

Renal Impairment: Use cautiously; monitor blood pressure and symptoms.

Hepatic Impairment: Use with caution; dose adjustments may be necessary.

Pharmacokinetics

Absorption: Well absorbed; extended-release formulations provide gradual absorption.

Distribution: Widely distributed; crosses the placenta and enters breast milk.

Metabolism: Extensively metabolized in the liver via CYP3A4.

Excretion: Primarily via feces, with some renal excretion.

Half Life: Approximately 2-4 hours for immediate-release; longer for extended-release formulations.

Contraindications

  • Hypersensitivity to nifedipine or other dihydropyridines.
  • Acute myocardial infarction with cardiogenic shock.

Precautions

  • Severe aortic stenosis, heart failure, hypotension, unstable angina. Use cautiously in patients with liver impairment; monitor for signs of hypotension and reflex tachycardia.

Adverse Reactions - Common

  • Headache (Common)
  • Dizziness (Common)
  • Peripheral edema (Common)
  • Flushing (Common)

Adverse Reactions - Serious

  • Hypotension (Serious)
  • Reflex tachycardia (Serious)
  • Arrhythmias (Serious)
  • Allergic reactions (Rare)

Drug-Drug Interactions

  • CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) increase nifedipine levels.
  • Other antihypertensives may have additive effects.

Drug-Food Interactions

  • Grapefruit juice can increase nifedipine levels.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, heart rate, signs of edema, and liver function.

Diagnoses:

  • Risk for hypotension
  • Ineffective tissue perfusion

Implementation: Administer as prescribed; monitor for adverse effects; educate patient on symptoms of hypotension.

Evaluation: Assess blood pressure response and symptom relief.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Do not suddenly stop medication.
  • Monitor for signs of swelling, dizziness, or irregular heartbeat.
  • Avoid grapefruit juice while on this medication.

Special Considerations

Black Box Warnings:

  • Use with caution in patients with severe aortic stenosis due to risk of worsening cardiac function.

Genetic Factors: Metabolized by CYP3A4; genetic variations may affect levels.

Lab Test Interference: May cause false low BP readings with certain cuff sizes or devices.

Overdose Management

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

Treatment: Discontinue nifedipine; supportively manage blood pressure with IV fluids or vasopressors as needed; activated charcoal may be considered if ingestion was recent.

Storage and Handling

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

Stability: Stable under proper storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.