Home Drug Guide Isosorbide Dinitrate

Drug Guide

Generic Name

Isosorbide Dinitrate

Brand Names Isordil, Sorbitrate, Dilatrate-SR

Classification

Therapeutic: Antianginal agent

Pharmacological: Nitrate (vasodilator)

FDA Approved Indications

  • Angina pectoris

Mechanism of Action

Isosorbide Dinitrate relaxes vascular smooth muscle by releasing nitric oxide, which stimulates guanylate cyclase to increase cyclic GMP levels, leading to vasodilation. This reduces myocardial oxygen demand and alleviates anginal symptoms.

Dosage and Administration

Adult: Typically 5-40 mg 3-4 times daily, taken on an empty stomach. Dose titration based on response.

Pediatric: Use is not generally approved for pediatric patients; consult specific clinical guidelines.

Geriatric: Start at lower end of dosing range; monitor for hypotension and tolerance.

Renal Impairment: Use cautious dosing; may require dose adjustments.

Hepatic Impairment: Use with caution; liver function impairment may affect drug metabolism.

Pharmacokinetics

Absorption: Well absorbed orally, subject to first-pass metabolism.

Distribution: Distributed widely in body tissues.

Metabolism: Primarily hepatic via conjugation and oxidation.

Excretion: Excreted mainly in urine as metabolites.

Half Life: 1-4 hours for immediate-release; longer for sustained-release formulations.

Contraindications

  • Hypersensitivity to nitrates
  • Concurrent use with phosphodiesterase inhibitors (e.g., sildenafil)

Precautions

  • Use with caution in hypotension, increased intracranial pressure, anemia, or known glaucoma. Tolerance may develop with continuous use. Use during pregnancy only if clearly needed; data are limited.

Adverse Reactions - Common

  • Headache (Very common)
  • Dizziness (Common)
  • Flushing (Common)
  • Orthostatic hypotension (Uncommon)

Adverse Reactions - Serious

  • Reflex tachycardia (Uncommon)
  • Methemoglobinemia (rare) (Rare)

Drug-Drug Interactions

  • Other antihypertensives, alcohol, phosphodiesterase inhibitors

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure and heart rate regularly. Assess for signs of hypotension or hemodyamic instability.

Diagnoses:

  • Ineffective tissue perfusion related to decreased blood pressure
  • Risk for injury related to dizziness or hypotension

Implementation: Administer tablets intravenously in emergency, under supervision. Educate patients on proper use and side effects.

Evaluation: Evaluate for relief of anginal attacks, monitor blood pressure and tolerance. Adjust doses as necessary.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Be aware of possible headache and dizziness. Avoid driving if dizzy.
  • Report any signs of severe headache, hypotension, or allergic reactions.
  • Do not switch formulations without consulting healthcare provider.

Special Considerations

Black Box Warnings:

  • None specific for Isosorbide Dinitrate.

Genetic Factors: Nitrate tolerance may develop more rapidly in some individuals.

Lab Test Interference: No significant interference noted.

Overdose Management

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

Treatment: Discontinue drug immediately. Supportive care including intravenous fluids and vasopressors if necessary. Seek emergency medical attention.

Storage and Handling

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

Stability: Stable for 24 months when stored properly.

🛡️ 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.