| Abstract: | A pharmacodynamic study was run in 12 healthy volunteers (4 male, 8 female, mean age 33.3 years, mean body-weight 60.8 kg) to demonstrate a dose- and time-effectiveness dependency for a beta 2-mimetic drug (clenbuterol, Spiropent) versus salbutamol and placebo as reference. A newly developed 3-dimensional tremormeter was introduced in this randomised double-blind/6-way/cross-over study. The shape of the induced tremor effects (in amplitude) as well as the pulse frequency reflected highly significant dose relationships. Drug effects started 30 min after intake and lasted longer than 600 min. 10 micrograms of clenbuterol revealed no significant differences when compared to placebo, whereas the 20 micrograms dosage as usually administered in clinical routine demonstrated significant--but only slight--differences to placebo-baseline. All other dosages and the reference (salbutamol, 8 mg) could be discriminated distinctly against placebo. |
