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Problem-based review: calcium channel blocker (CCB) poisoning
1University Hospitals, Coventry and Warwickshire, UK. tomheaps@hotmail.co.uk
Acute Medicine
|September 10, 2011
Summary
A massive overdose of sustained-release verapamil caused severe bradycardia and hypotension in a patient. Prompt medical intervention is crucial for managing verapamil toxicity and its cardiovascular effects.
Area of Science:
- Cardiology
- Clinical Toxicology
- Emergency Medicine
Background:
- Verapamil is a calcium channel blocker used for hypertension and arrhythmias.
- Sustained-release formulations increase overdose risk due to prolonged drug absorption.
- Overdosing on verapamil can lead to significant cardiovascular compromise.
Observation:
- A 56-year-old female ingested 3360 mg of sustained-release verapamil.
- She presented with sinus bradycardia (HR 50/min) and hypotension (BP 100/64).
- ECG revealed sinus bradycardia with a prolonged PR interval.
Findings:
- The patient's presentation was consistent with significant verapamil toxicity.
- The overdose resulted in severe bradycardia and hypotension.
- The prolonged PR interval on ECG indicated impaired atrioventricular conduction.
Implications:
- This case highlights the potential severity of verapamil overdose, even with sustained-release formulations.
- Aggressive management, including supportive care and potential antidotes, is vital.
- Understanding the pharmacokinetics and pharmacodynamics of verapamil is crucial for emergency physicians treating overdose patients.
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