Isoprenaline: Uses, Dosage, Side Effects & Mechanism | DrugsAtlas
Authoritative Clinical Reference
DRUG NAME: Isoprenaline
Therapeutic Class: Sympathomimetic
Subclass: Non-selective β-adrenergic agonist
Speciality: Cardiology
Schedule (India): Schedule H
Route(s): Intravenous (IV), Intramuscular (IM), Subcutaneous (SC)
Formulations Available in India:
• Isoprenaline injection: 1 mg/mL in 2 mL ampoule
• Isoprenaline injection: 0.2 mg/mL in 1 mL ampoule
• Isoprenaline injection: 0.2 mg/mL in 1 mL ampoule
INDICATIONS + DOSING — FOR CLINICIAN USE ONLY
Primary Indications (Approved / Standard in India)
1. Symptomatic Bradyarrhythmias (including complete heart block) — Emergency/Bridge Therapy
Intravenous Infusion (Preferred Route):
| Parameter | Recommendation |
| Starting dose | 0.5–1 mcg/min IV infusion (approximately 0.01 mcg/kg/min) |
| Titration | Increase by 0.5–1 mcg/min every 10–15 minutes based on heart rate and BP response |
| Usual maintenance dose | 2–10 mcg/min (0.02–0.1 mcg/kg/min) |
| Maximum dose | 20 mcg/min (approximately 0.2 mcg/kg/min) in refractory cases |
Intramuscular/Subcutaneous (Alternate when IV not feasible):
| Parameter | Recommendation |
| Starting dose | 0.2 mg IM or SC |
| Titration | May repeat after 2–4 hours if required based on clinical response |
| Usual maintenance dose | 0.2–0.4 mg per dose |
| Maximum dose | 1 mg per single dose |
Clinical Notes:
→ Temporary measure only — definitive therapy is cardiac pacing
→ Continuous ECG monitoring mandatory throughout infusion
→ Correct hypovolaemia and electrolyte abnormalities before initiation
→ Dilute IV preparation in 5% dextrose or 0.9% saline before infusion
→ Never administer undiluted IV bolus — risk of fatal arrhythmias
→ Temporary measure only — definitive therapy is cardiac pacing
→ Continuous ECG monitoring mandatory throughout infusion
→ Correct hypovolaemia and electrolyte abnormalities before initiation
→ Dilute IV preparation in 5% dextrose or 0.9% saline before infusion
→ Never administer undiluted IV bolus — risk of fatal arrhythmias
2. Acute Severe Bronchospasm (Historical/Limited Use)
| Parameter | Recommendation |
| Starting dose | 0.1–0.2 mg SC or IM |
| Titration | Not applicable |
| Usual maintenance dose | 0.1–0.2 mg every 4–6 hours |
| Maximum dose | 0.4 mg per dose; duration ≤24 hours |
Clinical Notes:
→ Reserved only when selective β2-agonists (salbutamol, terbutaline) are unavailable
→ Higher cardiac adverse effect profile than selective agents
→ Not recommended as first-line bronchodilator
→ Reserved only when selective β2-agonists (salbutamol, terbutaline) are unavailable
→ Higher cardiac adverse effect profile than selective agents
→ Not recommended as first-line bronchodilator
Secondary Indications – Adults (Off-label, if any)
1. Post-Cardiac Transplant Bradycardia (OFF-LABEL)
• Dose: 0.5–2 mcg/min IV infusion; titrate to target heart rate 80–100 bpm
• Duration: Short-term bridge until chronotropic response recovers or pacemaker placed
• Specialist only: Cardiac transplant units
• Evidence basis: Standard practice in cardiac transplant centres; institutional protocols
• Dose: 0.5–2 mcg/min IV infusion; titrate to target heart rate 80–100 bpm
• Duration: Short-term bridge until chronotropic response recovers or pacemaker placed
• Specialist only: Cardiac transplant units
• Evidence basis: Standard practice in cardiac transplant centres; institutional protocols
2. Torsades de Pointes (Drug-Induced or Pause-Dependent) (OFF-LABEL)
• Dose: 2–10 mcg/min IV infusion to increase heart rate >90 bpm
• Duration: Until causative agent cleared or temporary pacing established
• Specialist only: CCU/electrophysiology setting
• Evidence basis: Established electrophysiology practice; shortens QT interval by increasing heart rate
• Dose: 2–10 mcg/min IV infusion to increase heart rate >90 bpm
• Duration: Until causative agent cleared or temporary pacing established
• Specialist only: CCU/electrophysiology setting
• Evidence basis: Established electrophysiology practice; shortens QT interval by increasing heart rate
PAEDIATRIC DOSING (Specialist Only)
Primary Indications (Approved / Standard in India)
Symptomatic Bradycardia / Complete Heart Block — Emergency/Bridge to Pacing
| Parameter | Recommendation |
| Starting dose | 0.05 mcg/kg/min IV continuous infusion |
| Titration | Increase by 0.05 mcg/kg/min every 10–15 minutes based on heart rate response |
| Usual maintenance dose | 0.1–0.2 mcg/kg/min |
| Maximum dose | 0.5 mcg/kg/min |
Alternative Route (IM/SC) — when IV access not available:
| Parameter | Recommendation |
| Starting dose | 0.01 mg/kg (10 mcg/kg) IM or SC |
| Titration | May repeat after 4–6 hours if necessary |
| Usual maintenance dose | Individualised based on response |
| Maximum dose | 0.25 mg per single dose |
Clinical Notes:
→ Continuous ECG and BP monitoring mandatory
→ Specialist paediatric cardiology or PICU supervision required
→ Minimum age: May be used in neonates under specialist supervision
→ Correct hypokalaemia and acidosis before or during therapy
→ Prepare for emergency temporary pacing if available
→ Continuous ECG and BP monitoring mandatory
→ Specialist paediatric cardiology or PICU supervision required
→ Minimum age: May be used in neonates under specialist supervision
→ Correct hypokalaemia and acidosis before or during therapy
→ Prepare for emergency temporary pacing if available
Secondary Indications – Paediatric doses (Off-label, if any)
• Not routinely established in paediatric practice
• Any off-label use requires paediatric cardiology specialist input
• Use in neonates only under specialist supervision in tertiary centres with pacing capability
• Any off-label use requires paediatric cardiology specialist input
• Use in neonates only under specialist supervision in tertiary centres with pacing capability
RENAL ADJUSTMENT
• No specific dose adjustment required
• Use with caution in severe renal impairment — increased susceptibility to arrhythmias due to electrolyte disturbances
• Monitor serum potassium closely
• Use with caution in severe renal impairment — increased susceptibility to arrhythmias due to electrolyte disturbances
• Monitor serum potassium closely
HEPATIC ADJUSTMENT
| Severity (Child-Pugh) | Recommendation |
| Class A (Mild) | No dose adjustment required |
| Class B (Moderate) | Use with caution; drug may accumulate due to reduced hepatic metabolism |
| Class C (Severe) | Specialist use only; initiate at lower dose with slower titration; close ECG monitoring |
CONTRAINDICATIONS
• Tachyarrhythmias (ventricular tachycardia, ventricular fibrillation, supraventricular tachycardia)
• Phaeochromocytoma — risk of severe hypertensive crisis
• Known hypersensitivity to isoprenaline or any excipient
• Digitalis toxicity with arrhythmias
• Concurrent use with MAO inhibitors (within 14 days)
• Uncorrected hypovolaemia
• Phaeochromocytoma — risk of severe hypertensive crisis
• Known hypersensitivity to isoprenaline or any excipient
• Digitalis toxicity with arrhythmias
• Concurrent use with MAO inhibitors (within 14 days)
• Uncorrected hypovolaemia
CAUTIONS
• Coronary artery disease — increased myocardial oxygen demand may precipitate ischaemia
• Hypertrophic obstructive cardiomyopathy — may worsen outflow obstruction
• Hyperthyroidism — enhanced sensitivity to catecholamines
• Diabetes mellitus — may cause transient hyperglycaemia
• Hypokalaemia — increases arrhythmia risk; correct before or during therapy
• Elderly patients — increased cardiac sensitivity
• Patients receiving volatile anaesthetics — enhanced arrhythmogenic potential
• Hypertrophic obstructive cardiomyopathy — may worsen outflow obstruction
• Hyperthyroidism — enhanced sensitivity to catecholamines
• Diabetes mellitus — may cause transient hyperglycaemia
• Hypokalaemia — increases arrhythmia risk; correct before or during therapy
• Elderly patients — increased cardiac sensitivity
• Patients receiving volatile anaesthetics — enhanced arrhythmogenic potential
PREGNANCY
| Parameter | Guidance |
| Overall safety | Limited human data; use only when clearly indicated and alternatives ineffective |
| When permissible | Severe bradyarrhythmia unresponsive to atropine; life-threatening situation |
| Preferred alternatives | Atropine for bradycardia; transcutaneous pacing if available |
| Monitoring | Continuous maternal ECG and BP; fetal heart rate monitoring; avoid prolonged use |
LACTATION
| Parameter | Guidance |
| Breastfeeding compatibility | Unknown; likely minimal transfer due to short half-life |
| Milk levels | Expected to be low |
| Preferred alternatives | Avoid if possible; use only in emergency settings |
| Infant monitoring | If unavoidable, observe infant for tachycardia, irritability, poor feeding |
ELDERLY
• Starting dose: Use lower end of range (0.5 mcg/min IV or 0.1 mg IM/SC)
• Titration: Slower increments with extended observation intervals (every 20–30 minutes)
• Increased risks:
• Titration: Slower increments with extended observation intervals (every 20–30 minutes)
• Increased risks:
- Enhanced sensitivity to chronotropic and inotropic effects
- Higher incidence of arrhythmias including ventricular ectopy
- Risk of myocardial ischaemia or infarction
- Falls risk post-therapy due to postural hypotension
• Continuous ECG monitoring essential
• Avoid prolonged use
MAJOR DRUG INTERACTIONS
| Interacting Drug | Effect | Management |
| MAO inhibitors (phenelzine, tranylcypromine, selegiline) | Severe potentiation of sympathomimetic effects; hypertensive crisis; fatal arrhythmias | CONTRAINDICATED — avoid within 14 days of MAOI use |
| Digitalis glycosides (digoxin) | Synergistic arrhythmogenic effect; risk of ventricular arrhythmias especially with hypokalaemia | AVOID concurrent use; if essential, intensive ECG monitoring |
| Halogenated anaesthetics (halothane, sevoflurane) | Sensitise myocardium to catecholamines; increased arrhythmia risk | Avoid or use minimal doses; inform anaesthetist |
| Non-selective β-blockers (propranolol) | Antagonise bronchodilator effect; may cause paradoxical bronchospasm | Avoid combination |
MODERATE DRUG INTERACTIONS
| Interacting Drug | Effect | Management |
| Tricyclic antidepressants (amitriptyline, imipramine) | Enhanced cardiovascular effects; increased arrhythmia risk | Use with caution; monitor ECG and heart rate |
| Loop diuretics (furosemide) | Additive hypokalaemia → increased arrhythmia susceptibility | Monitor serum potassium; replete if low |
| Thiazide diuretics | Additive hypokalaemia | Monitor electrolytes |
| Theophylline | Additive cardiac stimulation; hypokalaemia | Monitor heart rate and potassium levels |
| Corticosteroids (systemic) | May potentiate hypokalaemic effect | Monitor serum potassium |
| Sympathomimetics (adrenaline, dopamine) | Additive cardiovascular stimulation; increased arrhythmia risk | Use together only with close monitoring in ICU setting |
COMMON ADVERSE EFFECTS
• Palpitations
• Tachycardia
• Headache
• Flushing
• Tremor
• Nervousness or restlessness
• Nausea
• Dizziness
• Tachycardia
• Headache
• Flushing
• Tremor
• Nervousness or restlessness
• Nausea
• Dizziness
SERIOUS ADVERSE EFFECTS
• Ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation) — discontinue immediately; initiate resuscitation if needed
• Myocardial ischaemia or infarction — particularly in patients with underlying coronary artery disease
• Severe hypotension — due to peripheral β2-mediated vasodilation at high doses
• Pulmonary oedema — rare; may occur with prolonged high-dose infusion
• Sudden cardiac death — associated with IV bolus administration or overdose
• Severe hypokalaemia — may precipitate life-threatening arrhythmias
• Myocardial ischaemia or infarction — particularly in patients with underlying coronary artery disease
• Severe hypotension — due to peripheral β2-mediated vasodilation at high doses
• Pulmonary oedema — rare; may occur with prolonged high-dose infusion
• Sudden cardiac death — associated with IV bolus administration or overdose
• Severe hypokalaemia — may precipitate life-threatening arrhythmias
MONITORING REQUIREMENTS
Baseline:
• 12-lead ECG
• Serum electrolytes (particularly potassium and magnesium)
• Blood pressure
• Heart rate
• Cardiac history review (rule out ischaemic heart disease, structural abnormalities)
• 12-lead ECG
• Serum electrolytes (particularly potassium and magnesium)
• Blood pressure
• Heart rate
• Cardiac history review (rule out ischaemic heart disease, structural abnormalities)
During Therapy:
• Continuous ECG monitoring (mandatory)
• Heart rate every 5–10 minutes during titration
• Blood pressure every 10–15 minutes
• Urine output monitoring
• Serum potassium every 6–12 hours for prolonged infusions
• Watch for chest pain or new ST-T changes
• Continuous ECG monitoring (mandatory)
• Heart rate every 5–10 minutes during titration
• Blood pressure every 10–15 minutes
• Urine output monitoring
• Serum potassium every 6–12 hours for prolonged infusions
• Watch for chest pain or new ST-T changes
Post-Infusion:
• ECG to assess for residual arrhythmias
• Monitor for rebound bradycardia
• Reassess need for permanent pacing
• ECG to assess for residual arrhythmias
• Monitor for rebound bradycardia
• Reassess need for permanent pacing
BRANDS AVAILABLE IN INDIA
• Isuprel (Abbott)
• Isopren (Samarth Pharma)
• Other institutional/generic preparations in select tertiary hospitals
• Isopren (Samarth Pharma)
• Other institutional/generic preparations in select tertiary hospitals
PRICE RANGE (INR)
• ₹40–₹80 per ampoule (1–2 mL)
• NLEM status: Not included
• Availability: Primarily in tertiary care centres, emergency departments, and cardiac care units
• Government supply: Limited; available in select emergency drug kits
• NLEM status: Not included
• Availability: Primarily in tertiary care centres, emergency departments, and cardiac care units
• Government supply: Limited; available in select emergency drug kits
CLINICAL PEARLS
• Temporary bridge therapy only — always plan for definitive pacing in complete heart block
• Atropine is first-line for bradycardia; isoprenaline reserved when atropine fails or is contraindicated
• Never give undiluted IV bolus — dilute and infuse slowly to prevent fatal arrhythmias
• Tachyphylaxis develops rapidly with prolonged infusion — effectiveness diminishes after 24–48 hours
• Correct hypokalaemia before or during therapy to minimise arrhythmia risk
• Avoid in atrial fibrillation with accessory pathways (WPW syndrome) — may accelerate ventricular response
• Keep emergency resuscitation equipment available during infusion
• Atropine is first-line for bradycardia; isoprenaline reserved when atropine fails or is contraindicated
• Never give undiluted IV bolus — dilute and infuse slowly to prevent fatal arrhythmias
• Tachyphylaxis develops rapidly with prolonged infusion — effectiveness diminishes after 24–48 hours
• Correct hypokalaemia before or during therapy to minimise arrhythmia risk
• Avoid in atrial fibrillation with accessory pathways (WPW syndrome) — may accelerate ventricular response
• Keep emergency resuscitation equipment available during infusion
TAGS
isoprenaline; isoproterenol; bradycardia; heart-block; sympathomimetic; beta-agonist; cardiac-emergency; bridge-to-pacing; ICU-drug; Schedule-H
VERSION
RxIndia v1.0 — 28 Feb 2026
REFERENCES
• Indian Pharmacopoeia
• CDSCO Approved Product Information
• NFI (National Formulary of India)
• API Textbook of Medicine
• AIIMS Emergency Drug Protocols
• Harrison’s Principles of Internal Medicine
• Goodman & Gilman’s The Pharmacological Basis of Therapeutics
• CDSCO Approved Product Information
• NFI (National Formulary of India)
• API Textbook of Medicine
• AIIMS Emergency Drug Protocols
• Harrison’s Principles of Internal Medicine
• Goodman & Gilman’s The Pharmacological Basis of Therapeutics
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This platform is designed strictly for healthcare professionals. Data provided is synthesized from authoritative pharmacological sources and clinical registries. Do not use for consumer medical decisions. Always verify critical dosing and contraindications with official institutional protocols and peer-reviewed journals.
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