Management overview for poisoning due to less-sedating antihistamines

This monograph discusses the management of poisonings due to less-sedating antihistamines (histamine H₁-receptor antagonists). For advice on the management of poisonings due to sedating antihistamines, see Antihistamine poisoning: sedating antihistamines.

Less-sedating antihistamines available in Australia include cetirizine, desloratadine, fexofenadine and loratadine. Fexofenadine and loratadine are available as coformulations with pseudoephedrine; in poisoning, the stimulant effects of pseudoephedrine are more prominent than the less-sedating antihistamine effects (see also Stimulant drug poisoning).

Poisonings due to less-sedating antihistamines are usually benign, with most patients only developing minor nausea and sedation. Most patients can be managed with supportive care. Cardiotoxicity is unlikely; however, patients with heart disease have a higher risk of developing QT-interval prolongation and torsades de pointes.