title: Comparison of class II and class III activity of dl-sotalol in healthy volunteers.
abstract: Racemic sotalol has demonstrated anti-arrhythmic properties which include Class II (beta blockade) and Class III (potassium channel blockade) activity. The Class II activity is demonstrated primarily in l-sotalol, and Class III activity is almost equipotent in each isomer. Class II and Class III activity of dl-sotalol was investigated following repeated oral administration (80 mg b.i.d.) for 7 days. Class II activity was evaluated according to the low frequency spectral power obtained by fast Fourier analysis of the R-R interval variation. Class III activity was evaluated according to the change in the QTc interval of the surface electrocardiogram. The low frequency spectral power decreased after administration of the first dose on day 1 and this trend continued throughout the duration of the study. The QTc interval did not change with dl-sotalol administration. These findings may suggest that Class II activity is more potent than Class III activity.
authors.affiliation: Department of Clinical Pharmacology, Hamamatsu University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Umemura
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeda
authors.forename: K
authors.initials: K
authors.lastname: Kosuge
authors.forename: M
authors.initials: M
authors.lastname: Nishimoto
authors.forename: K
authors.initials: K
authors.lastname: Ohashi
authors.forename: M
authors.initials: M
authors.lastname: Nakashima
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D000638:Amiodarone / Q000494:pharmacology; D000704:Analysis of Variance; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D026902:Potassium Channel Blockers; D013015:Sotalol / Q000494:pharmacology*; D013565:Sympatholytics / Q000494:pharmacology*
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D026902:Potassium Channel Blockers; D013565:Sympatholytics; D013015:Sotalol; D000638:Amiodarone