PROTOCOL FOR THE IV ADMINISTRATION OF ISOPRENALINE

INFORMATION/INDICATIONS

Isoprenaline stimulates both β1 and β2 adrenoceptors producing an increase in cardiac output by increasing both myocardial contractility and heart rate.

In patients with systemic hypotension, signs of cerebral hypoperfusion, progressive heart failure, angina, or life-threatening ventricular arrhythmia, medical therapy should be started immediately until temporary pacing is initiated.

External pacing does not provide reliable ventricular stimulation and should only be considered when administration of a chronotropic drug, temporary or permanent pacing is not available.

Currently we are only able to obtain isoprenaline sulfate 5mg/5ml.

Isoprenaline sulfate 2.25mg = Isoprenaline hydrochloride 2mg

All prescriptions should be prescribed in terms of isoprenaline hydrochloride. There are various strengths and salts of isoprenaline.

ADMINISTRATION

Preferably administered via a central venous access to avoid potential venous irritation as the preparation has a low pH.

IV infusion via peripheral administration (in emergencies):

Please ensure that you double check the strength and salt form of preparation being administered and volume to be added to infusion bag.

The dose used for severe bradycardia is 1 – 4micrograms/min given by intravenous infusion.

Isoprenaline sulfate 5mg/5ml injection (unlicensed)

Remove 2.25ml from a 500ml bag of 5% Glucose

Add 2.25mls (2.25mg) of isoprenaline to a 500ml bag of 5% Glucose

Agitate to mix

Do NOT use Sodium Chloride 0.9%

This provides a final concentration of 2mg in 500mls (isoprenaline hydrochloride), which is equivalent to 4micrograms/ml. Commence infusion at a rate of 1micrograms/min (15mls/hr).

Dose in microgram/min 1 2 3 4 5 6 7 8 9 10

Infusion rate (ml/hr) 15 30 45 60 75 90 105 120 135 150

Consider titrating up in steps of 1micrograms/min at intervals of 2-3 minutes, until a satisfactory heart rate is achieved or adverse effects such as hypotension or ventricular arrhythmias occur. (Usual max: 10micrograms/min)

IV infusion in fluid restriction (central line only):

Isoprenaline sulfate 5mg/5ml injection (unlicensed)

Remove 2.25ml from a 50ml bag of 5% Glucose

Add 2.25mls of isoprenaline

(2.25mg) to a 50ml bag of 5% Glucose

Agitate to mix

Do NOT use Sodium Chloride 0.9%

This provides a final concentration of 2mg in 50mls (isoprenaline hydrochloride), which is equivalent to 40micrograms/ml.

Commence infusion at a rate of 1micrograms/min (1.5mls/hr)

Dose in microgram/min 1 2 3 4 5 6 7 8 9 10 Infusion rate (ml/hr) 1.5 3 4.5 6 7.5 9 10.5 12 13.5 15

CAUTIONS Isoprenaline should be used with caution in patients with ischaemic heart disease, diabetes, hypertension and hyperthyroidism.

SIDE EFFECTS Arrhythmias, sweating, tremor, headache and flushing.

DATE PREPARED REVIEW DATE PREPARED BY CHECKED BY Ceri Jones Sian-Tsung Tan January 2017 January 2020 Critical Care Pharmacist Cardiology SpR December 2018 UPDATED: Sukhpreet Sahota Rotational Medicines specialist Pharmacist January 2021 UPDATED: Reena Pankhania Julie Phillips Rotational Medicines Information MI/Formulary Pharmacist Pharmacist

Approved by the Drugs & Therapeutics Committee.

Questions to [email protected] ext 7114.