Diltiazem (Cardizem)

Question 1

Classification

Answer 1

Calcium Channel Blocker

Question 2

Mechanism of Action

Answer 2

• Blocks calcium from entering cardiac myocytes
• Prolongs the conduction of electrical impulses through AV node
• Causes vasodilation
• Decreases rate of ventricular response
• Decreases myocardial O2 demand

Question 3

Indications

Answer 3

• Ventricular rate control in rapid atrial fibrillation/flutter

Question 4

Contraindications

Answer 4

• Hypotension
• Heart block
• Heart failure

Question 5

Adverse Effects

Answer 5

• Flushing, headache, bradycardia, hypotension, heart block, myocardial depression, severe AV block, cardiac arrest in high doses

Question 6

Administration

Answer 6

• Adult: 0.25 mg/kg IV/IO over 2 minutes initial dose, repeat at 0.35 mg/kg IV/IO
• Peds: Not recommended

Question 7

Special Considerations

Answer 7

• Use with extreme caution in patients who are taking beta blockers as these two drug classes potentiate each other’s effects and toxicities
• Patients with a history of heart failure and heart block are at high risk for toxicity.