Contraindications of Propranolol
Propranolol is absolutely contraindicated in cardiogenic shock, sinus bradycardia, greater than first-degree heart block, bronchial asthma, and known hypersensitivity to the drug. 1
Absolute Contraindications
The FDA drug label and clinical guidelines establish the following as absolute contraindications 1, 2:
- Cardiogenic shock - Propranolol's negative inotropic effects can worsen cardiac output and precipitate fatal outcomes 1, 3
- Sinus bradycardia - Beta-blockade will further reduce heart rate, potentially causing hemodynamic compromise 1, 2
- Greater than first-degree heart block - Risk of complete heart block and cardiac arrest 1, 2
- Bronchial asthma - Non-selective beta-blockade causes bronchoconstriction through beta-2 receptor antagonism, which can trigger life-threatening bronchospasm 1, 2
- Known hypersensitivity to propranolol hydrochloride - Risk of anaphylaxis 1, 2
Relative Contraindications Requiring Extreme Caution
Cardiac Conditions
- Heart failure - Propranolol can precipitate or worsen heart failure, particularly in patients with cardiothoracic ratio >0.5 or prior history of congestive heart failure 2, 4
- Hypotension - Propranolol causes further blood pressure reduction and is contraindicated in patients with preexisting hypotension 2, 5
Pulmonary Disease
- Chronic obstructive pulmonary disease (COPD) - While not an absolute contraindication like asthma, propranolol significantly worsens airway function in COPD patients 6, 7. The American Heart Association guidelines state that COPD is NOT a contraindication to cardioselective beta-blockers, but propranolol is non-selective and should be avoided 2. If beta-blockade is required in COPD, use cardioselective agents (metoprolol, atenolol, bisoprolol) instead 8, 9
Metabolic Conditions
- Hypoglycemia or insulin-dependent diabetes mellitus - Propranolol masks hypoglycemic symptoms and delays recovery from hypoglycemia, creating particular risk in patients with difficult glycemic control or autonomic neuropathy 2, 9
Critical Clinical Pitfalls to Avoid
Drug Combination Hazards
- Never combine propranolol with non-dihydropyridine calcium channel blockers (verapamil or diltiazem) - This combination is absolutely contraindicated due to additive negative inotropic and chronotropic effects, which can precipitate cardiogenic shock 3, 2
Special Populations Requiring Inpatient Monitoring
When propranolol must be initiated despite relative contraindications, the American Academy of Pediatrics recommends inpatient hospitalization for 2:
- Infants ≤8 weeks of age
- Preterm infants <48 weeks postconceptional age
- Patients with cardiac or pulmonary risk factors
- Those with poor social support
Monitoring Requirements
- Baseline assessment - Complete cardiac and pulmonary examination, ECG (particularly in patients with low heart rate or cardiac history), and blood pressure measurement 2, 5
- During therapy - Monitor for bradycardia, hypotension, heart failure symptoms, bronchospasm, and hypoglycemia 2, 5
- Feeding schedule - Administer propranolol with feedings at intervals not exceeding 8 hours (6 hours in younger infants) to reduce hypoglycemia risk 2
Acute Illness Considerations
- Temporarily reduce dose or discontinue propranolol in patients with acute illness interfering with oral intake, vomiting, or diarrhea 2
- Close monitoring required for blood pressure and renal function, particularly in patients with refractory ascites or spontaneous bacterial peritonitis 2
When Propranolol Should Be Replaced
If beta-blockade is required but propranolol is contraindicated, substitute with cardioselective beta-1 selective agents 8, 9:
- Metoprolol (starting 12.5-25 mg twice daily in reactive airway disease) 8
- Atenolol (25-50 mg daily) 8
- Bisoprolol (2.5-10 mg daily, preferred in heart failure) 8
These agents minimize beta-2 receptor blockade, reducing bronchospasm risk while maintaining cardiac benefits 9, 7.