After accidentally taking a second 60 mg dose of extended‑release propranolol in one day, should I go to the emergency department?

Accidental Double-Dose Extended-Release Propranolol: Emergency Department Not Required

You do not need to go to the emergency department after accidentally taking a total of 120 mg extended-release propranolol in one day, as this dose is far below the threshold for life-threatening toxicity (>2,000 mg), but you should monitor yourself closely at home for at least 8 hours from the time of the second dose. 1

Why This Dose Is Below the Danger Threshold

• Your total ingested dose of 120 mg is significantly below the 2,000 mg threshold associated with severe toxicity in isolated propranolol overdoses 2
• Research on propranolol overdoses shows that severe toxicity (seizures, cardiac arrest, need for inotropes) typically occurs at doses exceeding 2,000 mg, with the lowest reported dose for severe toxicity being 2,000 mg 2
• Even among patients who ingested ≥2,000 mg of propranolol alone, only 53% developed severe toxicity, and most had favorable outcomes with supportive care 2
• Deaths from propranolol overdose have been reported only at doses ranging from 2,400–16,000 mg 2

What You Should Monitor at Home

Cardiovascular symptoms to watch for over the next 8 hours: 1

• Bradycardia: Heart rate dropping below 50 beats per minute
• Hypotension: Feeling dizzy, lightheaded, or faint (systolic blood pressure <90 mmHg)
• These are the most common toxic manifestations but are unlikely at your dose 3, 1

Neurological symptoms (rare at this dose but propranolol is highly lipophilic): 1

• Confusion, delirium, or altered consciousness
• Seizures (only reported at doses >2,000 mg in isolated ingestions) 2, 4

Metabolic and respiratory symptoms: 1

• Symptoms of low blood sugar (shakiness, sweating, confusion)
• Wheezing or difficulty breathing (bronchospasm can occur even after cardiovascular parameters normalize)

Timeline for monitoring: 1

• Extended-release formulations can delay symptom onset up to 8 hours after ingestion 3, 1
• If you remain completely asymptomatic with stable vital signs after 8 hours from your second dose, the risk has passed 1

When You SHOULD Go to the Emergency Department

Seek immediate emergency care if you develop any of these symptoms: 1, 5

• Heart rate consistently below 50 beats per minute
• Dizziness, lightheadedness, or feeling faint
• Confusion, extreme drowsiness, or difficulty staying awake
• Seizure activity
• Difficulty breathing or wheezing
• Chest pain or palpitations

Why Extended-Release Formulation Matters

• Extended-release propranolol 60 mg once daily produces lower peak blood levels (Cmax 9.5–11.4 ng/mL) compared to immediate-release formulations 6
• The sustained-release characteristics mean the drug is absorbed more slowly over 24 hours, reducing the risk of acute toxicity peaks 5, 6
• Your accidental double dose essentially mimics taking 120 mg once, which is within the therapeutic dosing range (usual maintenance is 120–160 mg daily for hypertension) 5

Important Caveats

• Do not take your next scheduled dose until 24 hours after the second (accidental) dose to avoid further accumulation
• Propranolol is the beta-blocker most associated with serious toxicity in overdose compared to other beta-blockers, but only at much higher doses than yours 7, 4
• If you have any underlying heart conditions, are elderly, or are taking other medications that affect heart rate or blood pressure, consider calling your physician or poison control (1-800-222-1222) for personalized advice 1

Prevention Going Forward

• Consider using a pill organizer or medication tracking app to prevent future accidental double-dosing 1
• Extended-release formulations require particular attention since they are dosed once daily 5