Home Drug Guide Diltiazem Hydrochloride

Drug Guide

Generic Name

Diltiazem Hydrochloride

Brand Names Cardizem, Cardizem Sr, Cardizem Cd, Dilacor Xr, Tiazac, Cardizem La, Cartia Xt, Taztia Xt, Dilt-cd, Diltzac, Diltiazem Hydrochloride In Dextrose 5%, Diltiazem Hydrochloride In 0.72% Sodium Chloride

Classification

Therapeutic: Antihypertensive, Antianginal

Pharmacological: Calcium Channel Blocker (Vasoselective, non-dihydropyridine)

FDA Approved Indications

  • Hypertension
  • Angina pectoris (chronic stable angina, vasospastic angina)
  • Chronic stable angina in certain cases

Mechanism of Action

Diltiazem inhibits calcium ion influx into vascular smooth muscle and cardiac muscle, leading to dilation of coronary and peripheral arteries, reducing cardiac contractility, and decreasing myocardial oxygen demand.

Dosage and Administration

Adult: Typically 180-420 mg daily in divided doses or once daily in sustained-release forms, titrated based on response.

Pediatric: Use not generally recommended; consult specialist for pediatric use.

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

Renal Impairment: Adjust dose cautiously; monitor blood pressure and heart rate.

Hepatic Impairment: Use with caution; dose adjustment may be necessary, as drug metabolism may be impaired.

Pharmacokinetics

Absorption: Well absorbed orally with peak plasma levels in 2-4 hours.

Distribution: Widely distributed; moderate protein binding (~90%).

Metabolism: Extensively metabolized in the liver via CYP3A4.

Excretion: Primarily via feces; small amount excreted in urine.

Half Life: 3-7 hours for immediate-release; longer for extended-release formulations.

Contraindications

  • Severe hypotension
  • 2nd or 3rd degree AV block (without pacemaker)
  • Acute myocardial infarction with pump failure

Precautions

  • Use cautiously in heart failure, hepatic impairment, and in patients on beta-blockers.

Adverse Reactions - Common

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

Adverse Reactions - Serious

  • Bradycardia (Serious)
  • AV block (heart block) (Serious)
  • Hypotension (Serious)
  • Worsening heart failure (Serious)

Drug-Drug Interactions

  • Beta-blockers (additive effect on heart rate and contractility)
  • Digoxin (may increase levels)
  • CYP3A4 inhibitors or inducers (alter metabolism)

Drug-Food Interactions

  • Grapefruit juice (increases plasma levels)

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, heart rate, and rhythm regularly.

Diagnoses:

  • Risk for hypotension
  • Impaired cardiac output

Implementation: Administer as prescribed, monitor vital signs, and observe for adverse effects.

Evaluation: Assess therapeutic effectiveness and adverse reactions; adjust dose accordingly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Do not stop abruptly to avoid precipitating angina or hypertension.
  • Report signs of swelling, dizziness, slow heartbeat, or chest pain.
  • Limit grapefruit juice to reduce interaction risk.

Special Considerations

Black Box Warnings:

  • May cause or exacerbate heart failure in some patients.
  • Use cautiously in patients with conduction abnormalities.

Genetic Factors: CYP3A4 polymorphisms may affect metabolism.

Lab Test Interference: May alter liver function tests; monitor accordingly.

Overdose Management

Signs/Symptoms: Severe bradycardia, hypotension, AV block, cardiogenic shock, and potentially death.

Treatment: Supportive care, activated charcoal if ingestion recent, calcium gluconate IV for calcium channel blocker overdose, vasopressors, and pacing if needed.

Storage and Handling

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

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.