Salts of medetomidine and optically active enantiomers, thereof, particularly the d-enantiomer are disclosed. These salts may be used to regulate the rate of the transdermal administration of active drugs. The transdermal delivery system comprises a drug impermeable backing layer and an adhesive layer wherein the medetomidine is dispersed throughout the adhesive layer.

Transdermal administration of dexmedetomidine, the dextrorotatory isomer of medetomidine, is described. The method involves sedating a patient by administering dexmedetomidine to a predetermined area of skin at an administration rate and for a time period effective to achieve the desired level of sedation. A therapeutic system for transdermally administering the drug is also provided. The therapeutic system is in the form of a skin patch which is a laminated composite of a backing layer, an optional anchor adhesive layer, a contact adhesive layer, and one or more additional layers.

Recurrent paroxysmal neuropsychiatric disorders selected from (1) acute dystonic reactions, (2) seizure disorders and (3) panic disorders may be treated by means of aerosol inhalation of (1) anticholinergic and/or antihistaminic agents, (2) benzodiazepines and (3) antihistaminic agents, respectively.