Risk factors for toxicity

Risk factors for toxicity from beta-blocker poisoning include:

• ingestion of propranolol or sotalol, which are the most toxic beta blockers
• ingestion of a modified-release preparation—metoprolol is the only beta blocker available as a modified-release preparation
• older age
• co-existing medical conditions (eg heart disease, cirrhosis)
• co-ingestion of other cardiovascular drugs (eg calcium channel blockers, digoxin, angiotensin converting enzyme inhibitors).