Diltiazem

Administration


Indications

  • Conversion of PSVT to NSR
  • Slow RVR in a-fib/flutter

Adult Dosing

  • Loading dose = 0.25mg/kg (max=20mg) IV bolus over 2min
    • If ineffective after 15min: 0.35mg/kg (max=25mg) over 2min
    • If effective: Start infusion at 5-15mg/hr

Pediatric Dosing

Special Populations

  • Pregnancy Rating: C
  • Lactation:
  • Renal Dosing: Not studied, use caution
  • Hepatic Dosing: Not studied, use caution

Contraindications

  • Allergy to drug/class
  • Infants <1yo
  • Wide-complex tachycardia due to bypass tract (e.g. WPW)
  • Symptomatic severe hypotension
  • Sick sinus syndrome/2nd or 3rd degree heart block if no pacemaker
  • PO: acute MI and pulmonary congestion
  • Ventricular tachycardia
  • Caution if:
    • Hypertrophic cardiomyopathy
    • LV dysfunction
    • Concomitant beta-blockade
    • Hepatic/renal impairment
    • Heart failure

Adverse Reactions

Serious

  • Bradycardia, AV block, BBB
  • Hypotension
  • CHF
  • SJS/TEN

Common

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

Pharmacology

  • 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