Influences of trospium chloride and oxybutynin on quantitative EEG in healthy volunteers

Trospium chloride and oxybutynin are two antimuscarinergic agents used in the treatment of unstable bladder, urge incontinence, combined stress urge incontinence and detrusor hyperreflexia. The possibility that these two drugs produce changes in central nervous electrical activity was examined in an open, prospective, phase I study involving 12 volunteers. Quantitative evaluation of the multichannel electroencephalogram obtained from young healthy volunteers showed statistically significant decreases in alpha and beta 1 activity after oxybutynin, but not after intravenous or oral administration of trospium chloride. The biological activity of both drugs was ascertained by continuous simultaneous recording of the heart rate. A decrease in heart rate was detected after oral administration of oxybutynin, and an increase was seen after i.v. administration of trospium chloride. The results suggest that trospium chloride is less likely to produce central nervous adverse effects than to oxybutynin.