• Type: Calcium channel blocker
  • Dosage Forms
    • IV: 25 mg/5 mL and 50 mg/10 mL bottles
    • Oral: 30 mg, 60 mg, 90 mg
  • Routes of Administration: IV, PO
  • Common Trade Names: Cardizem

Adult Dosing

Atrial fibrillation with rapid ventricular response (if hemodynamically stable)

  • Loading dose = 0.25 mg/kg (max=20 mg) IV bolus over 2 minutes
    • Can consider breaking down into 10 mg boluses in older patients to decrease risk of adverse reactions
    • If ineffective after 15 minutes: 0.35mg/kg (max=25mg) over 2 minutes
    • If effective: Start infusion at 5-15 mg/hr
      • Consider 30mg IR PO or home dose to avoid need for a drip

Supraventricular tachycardia (if hemodynamically stable)

  • Same as for atrial fibrillation with rapid ventricular response (see above)

Pediatric Dosing

Special Populations

Pregnancy Rating

  • Pregnancy Rating: C

Lactation risk

  • Lactation: Does appear to diffuse into breast milk, but doses are typically not harmful to infants

Renal Dosing

  • Adult: Not studied, use caution
  • Pediatric: Not studied, use caution

Hepatic Dosing

  • Adult: Not studied, use caution
  • Pediatric: Not studied, use caution


Adverse Reactions


  • Bradycardia, AV block, BBB
  • Hypotension
  • CHF


  • Peripheral edema
  • Elevated LFTs
  • Headache
  • Dizziness
  • Nausea/vomiting, diarrhea, contipation
  • Flushing, vasodilation
  • Gingival hyperplagia
  • Myalgia
  • Bronchitis, sinus congestion, dypsnea
  • Hemolytic anemia, thrombocytopenia
  • Extrapyramidal symptoms


  • Onset of action = 2-3min (IV)
  • Duration of action = 1-3hr (IV)
  • Half life: 3-5h
  • Metabolism: Hepatic
  • Excretion: Urine/feces

Mechanism of Action

  • Class IV - Inhibits Ca influx
    • Slows AV nodal conduction


See Also