No effect of terodiline on anticoagulation effect of warfarin and steady-state plasma levels of warfarin enantiomers in healthy volunteers.

The influence of terodiline (25 mg b.i.d.) on the anticoagulant effect and plasma levels of warfarin enantiomers was studied in 23 young healthy male volunteers. Racemic warfarin was first given for 24 days to determine the doses required for the subject's vitamin K-dependent coagulation factors to fall within 10-20% of the normal range, as determined by the Thrombotest. During continuous warfarin treatment (mean daily dose 5.3 mg, range 2.5-9.4 mg), terodiline or placebo was given for two weeks in a randomized and double-blind fashion, and then the drugs were crossed over and given for another two weeks. Terodiline did not influence the anticoagulant effect of warfarin or the plasma levels of the warfarin enantiomers. The results indicate that it should not be necessary to monitor patients on combined therapy with terodiline and warfarin more frequently than patients on warfarin monotherapy.

Tolerability and steady-state pharmacokinetics of terodiline and its main metabolites in elderly patients with urinary incontinence.

The elderly form an important target group for the treatment of urinary urge incontinence with drugs such as terodiline (Mictrol, Terolin). In order to evaluate its steady-state pharmacokinetics and tolerability in geriatric patients terodiline 12.5 mg b.d. was given to 28 hospitalized patients with urinary incontinence (mean age 85 years) for six weeks. The patients were monitored during the study and for 6 weeks afterwards, blood samples being taken at regular intervals. In addition to these multi-diseased and polymedicated patients, a small, homogenous group of healthy volunteers (mean age 40 years) was studied as a reference group, being given terodiline 12.5 mg b.d. for 2 weeks. Terodiline was generally well tolerated by the patients and no significant change in blood pressure or heart rate were found. One patient was withdrawn due to adverse effects. The mean terminal half-life of terodiline was 131 h and the clearance after oral administration (clearance/systemic availability) was 39 ml.min-1. The corresponding figures for the healthy volunteers were 57 h and 75 ml.min-1. The average steady-state serum concentration was 518 micrograms.l-1 in the geriatric patients and 238 micrograms.l-1 in the healthy volunteers. Steady-state was reached within 3 weeks in 20 of the 28 patients and within 5 weeks in 7 patients. In the geriatric patients the steady-state serum concentration of the main metabolite p-hydroxyterodiline, during the last three weeks on terodiline was 45 micrograms.l-1, 57 micrograms.l-1, and 45 micrograms.l-1, respectively, and a similar value was found in the healthy volunteers, 47 micrograms.l-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Single- and multiple-dose pharmacokinetics of terodiline in geriatric patients.

As a target group, geriataric patients were selected for pharmacokinetic studies with terodiline (Mictrol), an anticholinergic and calcium antagonist drug effective in the treatment of urinary incontinence. The single-dose kinetics in the geriatric patients (mean age 82 years) differed significantly from that previously found (Hallén et al. 1987) in healthy volunteers (mean age 35 years). There were higher peak serum concentrations (110 vs 79 micrograms.l-1), increased half-life (189 vs 60 h), lower renal clearance (4.0 vs 10.9 ml.min-1) and lower total clearance (29 vs 75 ml.min-1). Multiple-doses of 12.5 mg b.d. for 6-8 weeks resulted in a mean steady-state concentration of 642 micrograms.l-1, which was in agreement with the single dose parameters. The studied geriatric patients can be characterized not only as old, but also as frail, bedridden, having several diseases and polymedicated. The differences in pharmacokinetics between younger and elderly subjects can be attributed to a variety of complex factors, which may alter the clearance and/or the volume of distribution.