Search
isoproterenol
Tradename: Isuprel.
Indications:
1) severe, unresponsive bronchospasm (not 1st or 2nd line agent)
2) temporary management of torsades de pointes
3) hemodynamically significant bradycardia in denervated & transplanted hearts
4) temporary use in 3rd degree AV heart block until insertion of pacemaker
5) unresponsive cardiac shock
Dosage:
1) must be diluted
2) cardiac arrhythmias
a) 0.02-0.06 mg (0.1-0.3 mL of 1:5000 dilution) IV bolus
b) followed by IV saline bolus
c) infusion of 5-20 ug/min (1 mg in 500 mL = 2 ug/mL)
3) shock: infusion of 0.5-5 ug/min titrated to response
Injection: 0.2 mg/mL [1:5000] (5 mL)
Pharmacokinetics:
1) rapid onset of action
2) metabolized by tissues, GI tract, liver, lungs
3) duration of action approximately 1 hour
Adverse effects:
1) common (> 10%)
- discoloration of saliva (pinkish-red), insomnia, restlessness, dry mouth or throat
2) less common (1-10%)
- weakness, nausea/vomiting, trembling, hypertension, increased sweating, tachycardia, flushing of face, dizziness, lightheadedness
3) uncommon (< 1%)
- paradoxical bronchospasm, arrhythmias, chest pain
4) other
- ventricular ectopy
- tachycardia
- hypotension
- headache
- angina
- anxiety
- agitation
- flushing
Drug interactions:
1) beta blockers antagonize the effects of isoproterenol
2) general anesthetics in combination increase cardiac irritability
3) theophylline in combination increases cardiac toxicity
Mechanism of action:
1) directly stimulated beta-1 & beta-2 adrenergic receptors
2) cardiac effects
a) positive inotrope
b) increases cardiac output by increasing contractility & stroke volume
c) increases myocardial consumption of O2
d) decreases cardiac efficiency
e) shortens conduction time & refractory period of the AV node
f) decreases afterload
g) increases preload
h) increases systolic blood pressure
3) other effects (mainly beta-2 adrenergic effects)
a) relaxation of the bronchial tree
b) peripheral vasodilation
c) relaxes GI & uterine smooth muscle
d) inhibits slow-releasing substance of anaphylaxis
e) inhibits histamine release
f) CNS stimulation
g) glycogenolysis
h) stimulates insulin release (unlike epinephrine)
Interactions
drug adverse effects (more general classes)
General
beta-adrenergic receptor agonist
catecholamine
ethanolamine
Properties
AGONIST-FOR: beta adrenergic receptor
MISC-INFO: elimination route LIVER
KIDNEY
pregnancy-category C
safety in lactation ?
Database Correlations
PUBCHEM correlations
References
- Drug Information & Medication Formulary, Veterans Affairs,
Central California Health Care System, 1st ed., Ravnan et al
eds, 1998
- Kaiser Permanente Northern California Regional Drug
Formulary, 1998
Component-of
ca+2/iodine/isoproterenol
isoproterenol/phenylephrine