High affinity histamine H3 receptor neutral antagonist (pKi values are 8.9 and 9.2 in rat and human respectively). Brain penetrant and orally active. Has 3- and 100-fold higher affinity than thioperamide (Cat. No. 0644) for rat and human H3 receptors respectively. Suppresses slow-wave sleep; exhibits wake-promoting effects in rodent arousal models.