What is the treatment for levocetrizine (antihistamine) poisoning?

Treatment of Levocetirizine Poisoning

In case of levocetirizine overdose, immediately contact a Poison Control Center (1-800-222-1222) and provide supportive care, as there is no specific antidote for antihistamine poisoning. 1

Immediate Management

Initial Assessment and Stabilization

• Assess airway, breathing, and circulation first, as antihistamine overdose can cause CNS depression and respiratory compromise 1
• Contact Poison Control Center immediately for guidance on specific management strategies 1
• Monitor vital signs continuously, particularly respiratory rate and level of consciousness

Decontamination Considerations

• Activated charcoal may be considered if presentation is within 1-2 hours of ingestion and the patient has a protected airway, though this is based on general toxicology principles rather than levocetirizine-specific data
• Do not induce vomiting due to risk of aspiration with altered mental status

Supportive Care Measures

Symptomatic Management

• Provide supportive care as the mainstay of treatment, as no specific antidote exists for levocetirizine toxicity 1
• Manage drowsiness and sedation, which are the most common manifestations of antihistamine overdose 2, 3
• Monitor for and treat urinary retention, as antihistamines can cause difficulty urinating or emptying the bladder 1

Monitoring Parameters

• Continuous cardiac monitoring to detect any potential arrhythmias, though levocetirizine has minimal cardiovascular effects at therapeutic doses 4
• Monitor renal function, as levocetirizine is primarily renally excreted and accumulation may occur in overdose 2, 3
• Assess neurological status regularly for progression of sedation or development of seizures

Special Considerations

High-Risk Populations

• Patients with pre-existing kidney disease are at higher risk for toxicity and prolonged effects 1
• Infants require particular caution due to serious concerns about febrile seizures reported with levocetirizine use 5
• Elderly patients may experience more pronounced CNS effects

Drug Interactions in Overdose

• Avoid concurrent use of alcohol, sedatives, and tranquilizers, as these may potentiate drowsiness and CNS depression 1
• Be aware that levocetirizine has minimal hepatic metabolism and low potential for drug interactions under normal circumstances 4

Clinical Pitfalls to Avoid

• Do not assume mild symptoms mean benign course—monitor for delayed effects, particularly in children
• Do not discharge patients prematurely—observe until symptoms resolve and mental status normalizes
• Do not overlook urinary retention—this is a specific adverse effect that requires monitoring and potential intervention 1
• Remember that levocetirizine has a long duration of action (up to 24 hours), so prolonged observation may be necessary 6, 4

Disposition

• Admit patients with significant CNS depression, respiratory compromise, or inability to tolerate oral intake
• Patients with mild symptoms who improve with observation may be discharged after 4-6 hours if asymptomatic
• Provide clear return precautions regarding worsening drowsiness, difficulty breathing, or inability to urinate