Loratadine is an antihistaminergic drug with a tricyclic structure and a selective peripheral H-1-receptor activity [1]. Desloratadine is its primary active metabolite and is a non-sedating, long-acting histamine antagonist. After oral administration, desloratadine selectively blocks peripheral histamine H1-receptors

Loratadine is an antihistaminergic drug with a tricyclic structure and a selective peripheral H-1-receptor activity [1]. Desloratadine is its primary active metabolite and is a non-sedating, long-acting histamine antagonist. After oral administration, desloratadine selectively blocks peripheral histamine H1-receptors because the substance is excluded from entry to the central nervous system [2]. The antihistaminergic activity of desloratadine is 2.5 4 times as great as loratadine [3]. Loratadine and desloratadine have been approved for the Dutch market since 031989 and 01-2001, respectively [1]. Both drugs are indicated for the relief of symptoms associated with allergic rhinitis and chronic idiopathic urticaria [1,2]. Loratadine is marketed as an over-the-counter drug. Desloratadine is available on prescription. The Dutch SmPC of desloratadine mentions seizures as an adverse reaction: in the Dutch SmPC this is incorrectly and confusingly mentioned as “aanvallen”. No further information is given about the severity or incidence of this reaction [2]. In the Dutch SmPC of loratadine convulsions or seizures are not mentioned. The current observation describes the association between loratadine, desloratadine and convulsions.