Selected topics: toxicologyAre 1–2 tablets dangerous? Beta-blocker exposure in toddlers
Introduction
There are a wide variety of therapeutic indications for beta-adrenergic antagonists, better known as beta-blockers. They are most commonly used in cardiovascular disease. Other indications include migraine headache, tremor, panic attacks, and as medications to decrease intraocular pressures. In the pediatric population, beta-blockers are used primarily to treat hypertension, dysrhythmias, thyrotoxicosis, and migraine headache (1). Propranolol, the agent most commonly associated with overdose and toxicity, was released in 1964. By the 1970s there were 10 beta-blockers on the market that were widely used in the United States as anti-hypertensives and anti-anginal agents (2).
As the availability of this class of medication has increased, so have reports of overdose and toxicity. This article reviews the available literature of adverse events from beta-blocker exposure in toddlers. Included is a basic overview of the pathophysiology, pharmacokinetics, and treatment of beta-blocker intoxication. Finally, based on the available literature, risk is assessed and guidelines are presented for medical evaluation and disposition of children under 6 years of age who may have ingested 1–2 tablets.
Section snippets
Characteristics of beta-blockers
Beta-blockers are competitive antagonists of catecholamines at beta-adrenergic receptors. There are at least two subtypes of beta-adrenergic receptors, beta-1 and beta-2. Some beta-blocking agents are designed to selectively act at either the beta-1 or the beta-2 receptor. At low doses, medications such as atenolol and metoprolol are beta-1 selective; however, in larger doses, they lose their selectivity and act at both beta-1 and 2 receptors (3). In addition, beta-blockers also possess the
Management of serious beta-blocker overdose
Patients with suspected significant beta-blocker overdose or toxicity should be placed on a cardiac monitor, have frequent blood pressure monitoring, a 12-lead electrocardiogram (EKG), and a serum glucose determination. If congestive heart failure is suspected, a chest radiograph and oxygen saturation should be obtained. Serum beta-blocker levels may be helpful in questionable cases to establish a diagnosis (16). These levels are generally performed as a “send out” test by a reference
Beta-blocker toxicity in children
The annual number of beta-blocker exposures reported to the American Association of Poison Control Centers (AAPCC) has increased approximately fivefold in children under 6 years old over the last 19 years 21, 22. This is likely due to increased reporting to poison control centers and increased availability of these drugs. According to data from the AAPCC, for children under the age of 6 years, there were 37,066 reported exposures to beta-blockers between 1983 and 2001 21, 22, 23, 24, 25, 26, 27
Recommendations
There is no study that clearly defines the risk of toxicity in the toddler who ingests a beta-blocker. This likely explains why a recent survey of poison centers found no consistent triage practice in beta-blocker exposures involving children under 6 years of age (31). Beta-blockers have been in clinical use for nearly 40 years and are common exposures reported to the American Association of Poison Control Centers. With this extensive experience, there are no published deaths in toddlers as a
Summary
Exposure to 1–2 tablets of beta-blocker appears to place the toddler at very little risk of mortality or serious morbidity. A convincing argument can be made for home management without gut decontamination in those with a clear history of no more then two tablets of hydrophilic beta-blockers. The need for hospital evaluation after exposure to 1–2 tablets of a lipophilic agent should be made on a case-by-case basis. Although uncommon, hypoglycemia remains a concern. Encouraging oral caloric
References (38)
Clinical pharmacology of the new beta-adrenergic blocking drugs. Part 1. Pharmacodynamic and pharmacokinetic properties
Am Heart J
(1979)- et al.
Effects of propranolol and a number of its analogues on sodium channels
Biochem Pharmacol
(1982) - et al.
Clinical pharmacology of the new beta-adrenergic blocking drugs. Part 8. Self-poisoning with beta-adrenoceptor blocking agentsrecognition and management
Am Heart J
(1979) - et al.
Electrocardiographic changes associated with beta-blocker toxicity
Ann Emerg Med
(2002) Beta-blocker toxicity after overdosewhen do symptoms develop in adults?
J Emerg Med
(1994)- et al.
Clinical pharmacology of the new beta-adrenergic blocking drugs. Part 2. Physiologic and metabolic effects
Am Heart J
(1979) - et al.
Toxic psychosisan unusual presentation of propranolol intoxication
Am J Emerg Med
(1995) - et al.
2001 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
(2002) - et al.
1984 Annual report of the American Association Of Poison Control Centers National Data Collection System
Am J Emerg Med
(1985) - et al.
1996 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
(1997)
1997 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
1998 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
1999 Annual report of the American Association Of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
2000 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System
Am J Emerg Med
1987 Annual report of the American Association Of Poison Control Centers National Data Collection System
Am J Emerg Med
Oral propranolol treatment in infants and children
J Pediatr
Propranolol in childrensafety-toxicology
Pediatrics
Beta-adrenergic antagonists
Cardiovascular depression resulting from atenolol intoxication
Eur J Emerg Med
Cited by (109)
Potential applications and challenges of novel ambient ionization mass spectrometric techniques in the emergency care for acute poisoning
2022, TrAC - Trends in Analytical ChemistryIs hypoglycemia really observed in pediatric beta-blocker intoxications? A case–control study
2022, Archives de PediatrieAvailability in Spain of “one pill killers” and other highly toxic drugs in infants
2020, Anales de PediatriaStrategies for Blood Product Management, Reducing Transfusions, and Massive Blood Transfusion
2018, A Practice of Anesthesia for Infants and ChildrenAccidental poisonings of domestic child
2016, Journal de Pediatrie et de PuericultureCost-effectiveness of treating infantile haemangioma with propranolol in an outpatient setting
2018, Cardiology in the Young