The disposition of thioperamide, a histamine H3-receptor antagonist, in rats.

An HPLC method using an ovomucoid-conjugated column has been developed for measurement of thioperamide, a histamine H3 antagonist, with a minimum quantitation limit of 0.05 micrograms mL-1. The assay was used to study the disposition of thioperamide in rats. After bolus intravenous administration of thioperamide (10 mg kg-1), the plasma concentration decreased monoexponentially with a half-life of 26.9 min. The apparent total body clearance of thioperamide from rat plasma was 74.6 mL min-1 kg-1. Although thioperamide was quickly transferred to various tissues, its concentrations in peripheral tissues were higher than that in the brain. However, the brain regional tissue/plasma ratios of thioperamide increased continuously after its injection.