Verapamil

Revision as of 20:24, 26 January 2019 by Bmurray990 (talk | contribs) (Special Populations)
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Administration

Adult Dosing

  • Atrial fibrillation, paroxysmal SVT
    • IV: 5-10mg (0.075-0.15 mg/kg), may give an initial 10mg IV after 30 minutes if inadequate response
    • PO: 240-48 mg daily in 3-4 divided doses
  • Angina, hypertension: 80-120mg PO 3 times per day

Pediatric Dosing

  • Afib/flutter, SVT
    • IV 0.1-0.2 (<1yo) or 0.1-0.3 (>1yo) mg/kg. Repeat after 30 minutes if inadequate response
    • PO: 4-10 mg/kg/day in 3 divided doses

Special Populations

  • Pregnancy Rating: Verapapmil crosses the placenta and can cause adverse fetal effects such as heart block, hypotension, and bradycardia
  • Lactation risk: Present in breast milk with relative infant dose of <1% which is considered safe for the infant.
  • Renal dosing: Can accumulate causing increased effects, monitor closely and consider lowering dose.
  • Hepatic dosing: 20-50% of normal dose

Contraindications

Adverse Reactions

Serious

Common

Pharmacology

  • Half-life: 4-20 hours
  • Metabolism: Hepatic- P450 CYP3A4, CYP1A2, CYP2C8, CYP2C9 and CYP2C18
  • Excretion: Renal primarily. Not dialyzable

Mechanism of Action

  • Inhibits L-type (slow) calcium channels, blocking influx of calcium into myocardial cells
  • Reduces systemic vascular resistance, vasodiolates peripheral arteries

Comments

See Also

References