verapamil
Table of Contents
verapamil (Isoptin)
introduction
- a phenylalkylamine non-dihydropyridine calcium blocking agent
- acts mainly on arteriolar smooth muscle to reduce peripheral vascular resistance as well as having negative inotropic and AV conduction effects
main indications
C/I
- BP < 90mmHg
- sick sinus syndrome
- AV block without a pacemaker
- significant left ventricular failure (LVF)
- AF with pre-excitation syndromes including WPW (risk of ventricular fibrillation (VF))
- hypersensitivity
- pregnancy - class C
precautions
- concomitant beta adrenergic blockers risk AV blockade
- liver impairment
- grapefruit juice as this is an inhibitor of the CYP-3A4 enzyme and may cause toxicity of verapamil and other calcium channel blockers
- lactation
adverse effects
- hypotension
- negative inotropic effect and cardiac failure risk
- cardiac conduction blockade
- peripheral oedema which is NOT responsive to diuretics which will only cause volume depletion
- constipation
- rarely, myasthenia-like neuromuscular disease
- many possible drug interactions
dose
acute ED Rx of SVT or hypertension
- 3mg over 1-2min then 1mg per minute as needed up to 10mg max in adults
verapamil.txt · Last modified: 2015/12/31 04:28 by 127.0.0.1