Isoproterenol

Question 1

Isoproterenol- Name

Answer 1

Isuprel

Isuprel Mistometer

Norisodrine Aerotrol Sulfate

Question 2

Isoproterenol- Class

Answer 2

Sympathomimetic

Question 3

Isoproterenol- MoA

Answer 3

1) drug induced stimulation of beta-1 receptors results in:

-increased cardiac output by increasing strength of cardiac contractions and increasing heart rate (increased systolic BP)

2) drug induced stimulation of beta-2 receptors results in:

• dilates the arterioles of skeletal muscle, resulting in decreased PVR (decreased diastolic BP)
• relaxes bronchiole smooth muscles
• facilitates removal of pulmonary secretions by increasing ciliary motion

Question 4

Isoproterenol- Indications

Answer 4

Symptomatic bradycardia refractory to atropine when transcutaneous pacing is not available or an option.

bronchodilaton in asthma, COPD, and other conditions involving bronchospasms

Beta Blocker OD (may require higher doses)

Question 5

Isoproterenol- Contra

Answer 5

cardiogenic shock

Angina

tachydysrhythmias and heart blocks associated with digitalis overdose

ventricular arrhythmias

Question 6

Isoproterenol- S/E

Answer 6

Cardiovascular: flushing, palpitations, unstable BP, tachycardia, Ventricular dysrhythmias

CNS: headache, tremors, anxiety, nervousness

Question 7

Isoproterenol- Routes

Answer 7

IVPB, IV, IO

(can also be given via HHN or MDI)

Question 8

Isoproterenol- A. Dose

Answer 8

For Symptomatic Bradycardia:

2-10 mcg/min IVP/IVPB

titrated to desired heart rate

For Bronchospasms:

1-2 inhalations of MDI (metered dose inhaler)

Question 9

Isoproterenol- P. Dose

Answer 9

For Symptomatic Bradycardia:

0.1 mcg/min IVP/IVPB

titrated to desired heart rate

For Bronchospasms:

1-2 inhalations of MDI (metered dose inhaler)

Question 10

Isoproterenol- EXTRAS

Answer 10

Precautions: Use with extreme caution in patients with known or suspected electrolyte imbalance, due to propensity for dysrhythmias.

Interactions: Oxytocic drugs (Pitocin, Oxytocin) - possibility of persistent severe hypertension; Tricyclic Antidepressants – potentiation of pressor effect; Beta-Blocking drugs will antagonize the effects of isoproterenol.

Onset and Duration of Action: Inhalation: 2-5 minutes, with peak effect in 3-5 minutes, lasting for 30-120 minutes; IV: immediate, lasting less than 1 hr.

Notes: With the use of transcutaneous pacing in the prehospital setting, isoproterenol is now rarely used – but still prevalent in ACLS.