Pharmacotherapeutic group: Genito urinary system and sex hormones
Pharmacotherapeutic sub-group: Urinary antispasmodics
ATC Code: G04B D07
Mechanism of action
Tolterodine is a competitive, specific muscarinic receptor antagonist with a selectivity for the urinary bladder over salivary glands in vivo.
Pharmacodynamic effects
One of the tolterodine metabolites (5-hydroxymethyl derivative) exhibits a pharmacological profile similar to that of the parent compound. In extensive metabolisers this metabolite contributes significantly to the therapeutic effect (see section 5.2).
Clinical efficacy and safety
The effect of the treatment can be expected within 4 weeks.
In the Phase 3program, the primary endpoint was reduction of incontinence episodes per week and the secondary endpoints were reduction of micturitions per 24 hours and increase of mean volume voided per micturition. These parameters are presented in the following table.
The effect of treatment with tolterodine 4 mg once daily after 12 weeks, compared with placebo. Absolute change and percentage change relative to baseline. Treatment difference tolterodine vs. placebo: Least Squares estimated mean change and 95% confidence interval.
| | Tolterodine 4 mg once daily (n=507) | Placebo (n=508) | Treatment difference vs. placebo: Mean change and 95% CI | Statistical significance vs. placebo (p-value) |
| Number of incontinence episodes per week | -11.8 (-54%) | -6.9 (-28%) | -4.8 (-7.2; -2.5)* | <0.001 |
| Number of micturitions per 24 hours | -1.8 (-13%) | -1.2 (-8%) | -0.6 (-1.0; -0.2) | 0.005 |
| Mean volume voided per micturition (ml) | +34 (+27%) | +14 (+12%) | +20 (14; 26) | <0.001 |
*) 97.5% confidence interval according to Bonferroni
After 12 weeks of treatment 23.8% (121/507) in the tolterodine 4 mg group and 15.7% (80/508) in the placebo group reported that they subjectively had no or minimal bladder problems.
The effect of tolterodine was evaluated in patients, examined with urodynamic assessment at baseline and, depending on the urodynamic result, they were allocated to a urodynamic positive (motor urgency) or a urodynamic negative (sensory urgency) group. Within each group, the patients were randomised to receive either tolterodine or placebo. The study could not provide convincing evidence that tolterodine had effects over placebo in patients with sensory urgency.
The clinical effects of tolterodine on QT interval were studied in ECGs obtained from over 600 treated patients, including the elderly and patients with pre-existing cardiovascular disease. The changes in QT intervals did not significantly differ between placebo and treatment groups.
The effect of tolterodine on QT-prolongation was investigated further in 48 healthy male and female volunteers aged 18 – 55 years. Subjects were administered 2 mg BID and 4 mg BID tolterodine as the immediate release formulations. The results (Fridericia corrected) at peak tolterodine concentration (1 hour) showed mean QTc interval increases of 5.0 and 11.8 msec for tolterodine doses of 2 mg BID and 4 mg BID respectively and 19.3 msec for moxifloxacin (400 mg) which was used as an active internal control. A pharmacokinetic/pharmacodynamic model estimated that QTc interval increases in poor metabolisers (devoid of CYP2D6) treated with tolterodine 2 mg BID are comparable to those observed in extensive metabolisers receiving 4 mg BID. At both doses of tolterodine, no subject, irrespective of their metabolic profile, exceeded 500 msec for absolute QTcF or 60 msec for change from baseline that are considered thresholds of particular concern. The 4 mg BID dose corresponds to a peak exposure (Cmax) of three times that obtained with the highest therapeutic dose of tolterodine 4 mg capsules.
Paediatric population
The efficacy in the paediatric population has not been demonstrated. Two paediatric phase 3 randomised, placebo-controlled, double-blind 12 week studies were conducted using tolterodine extended release capsules. A total of 710 paediatric patients (486 on tolterodine and 224 on placebo) aged 5-10 years with urinary frequency and urge urinary incontinence were studied. No significant difference between the two groups was observed in either study with regard to change from baseline in total number of incontinence episodes/week (see section 4.8).