Home Drug Guide Isradipine

Drug Guide

Generic Name

Isradipine

Brand Names Dynacirc, Dynacirc CR

Classification

Therapeutic: Antihypertensive, Calcium channel blocker

Pharmacological: Dihydropyridine calcium channel blocker

FDA Approved Indications

  • Hypertension

Mechanism of Action

Isradipine inhibits calcium ions from entering vascular smooth muscle and cardiac muscle cells through voltage-gated L-type calcium channels, resulting in vasodilation and decreased blood pressure.

Dosage and Administration

Adult: Initial: 5 mg orally twice daily. Dose may be titrated up to 10 mg twice daily based on response.

Pediatric: Not approved for pediatric use.

Geriatric: Start at lower doses; monitor closely due to increased sensitivity.

Renal Impairment: No initial dose adjustment necessary; adjust as needed based on response.

Hepatic Impairment: Use with caution; dose adjustment may be necessary, especially in severe impairment.

Pharmacokinetics

Absorption: Well absorbed orally with peak plasma levels in 1-2 hours.

Distribution: Extensive tissue distribution; protein bound approximately 91%.

Metabolism: Primarily hepatic via CYP3A4.

Excretion: Metabolites excreted mainly in feces, minor renal excretion.

Half Life: Approximately 7-8 hours.

Contraindications

  • Hypersensitivity to dihydropyridines or any component of the formulation.
  • Concurrent use with strong CYP3A4 inhibitors in some cases.

Precautions

  • Use with caution in patients with severe aortic stenosis, heart failure, or hypotension.
  • Monitor blood pressure regularly during therapy.

Adverse Reactions - Common

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

Adverse Reactions - Serious

  • Hypotension (Less common)
  • Bradycardia or tachyarrhythmias (Rare)

Drug-Drug Interactions

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

Drug-Food Interactions

  • Grapefruit juice may increase plasma concentrations of isradipine.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure and heart rate regularly.

Diagnoses:

  • Risk for hypotension
  • Ineffective tissue perfusion related to vasodilation.

Implementation: Administer with food to minimize hypotension. Adjust doses based on response.

Evaluation: Assess blood pressure and symptom control regularly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Monitor for signs of hypotension (dizziness, fainting).
  • Avoid grapefruit juice during therapy.
  • Report any swelling, rapid heartbeat, or severe dizziness.

Special Considerations

Black Box Warnings:

  • None specifically for isradipine.

Genetic Factors: None established.

Lab Test Interference: None known.

Overdose Management

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

Treatment: Supportive care with IV fluids; vasopressors if necessary; activated charcoal if ingestion was recent.

Storage and Handling

Storage: Store at room temperature, away from moisture and heat.

Stability: Stable under recommended 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.