The Phase 2 and 3 clinical trial program for tolterodine tablets included 3071 patients who were treated with tolterodine (N = 2133) or placebo (N = 938). The patients were treated with 1, 2, 4, or 8 mg/day for up to 12 months. No differences in the safety profile of tolterodine were identified based on age, gender, race, or metabolism.
The data described below reflect exposure to tolterodine 2 mg BID in 986 patients and to placebo in 683 patients exposed for 12 weeks in five Phase 3, controlled clinical studies. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and approximating rates.
Sixty-six percent of patients receiving tolterodine 2 mg BID reported adverse events versus 56% of placebo patients. The most common adverse events reported by patients receiving tolterodine were dry mouth, headache, constipation, vertigo/dizziness, and abdominal pain. Dry mouth, constipation, abnormal vision (accommodation abnormalities), urinary retention, and xerophthalmia are expected side effects of antimuscarinic agents.
Dry mouth was the most frequently reported adverse event for patients treated with tolterodine 2 mg BID in the Phase 3 clinical studies, occurring in 34.8% of patients treated with tolterodine and 9.8% of placebo-treated patients. One percent of patients treated with tolterodine discontinued treatment due to dry mouth.
The frequency of discontinuation due to adverse events was highest during the first 4 weeks of treatment. Seven percent of patients treated with tolterodine 2 mg BID discontinued treatment due to adverse events versus 6% of placebo patients. The most common adverse events leading to discontinuation of tolterodine were dizziness and headache.
Three percent of patients treated with tolterodine 2 mg BID reported a serious adverse event versus 4% of placebo patients. Significant ECG changes in QT and QTc have not been demonstrated in clinical-study patients treated with tolterodine 2 mg BID. Table 5 lists the adverse events reported in 1% or more of the patients treated with tolterodine 2 mg BID in the 12 week studies. The adverse events are reported regardless of causality.
Table 5: Incidencein nearest integer
(%) of Adverse Events Exceeding Placebo Rate and Reported in > 1% of Patients Treated With Tolterodine Tablets (2 mg BID) in 12 week, Phase 3 Clinical Studies Body System | Adverse Event | % TolterodineN = 986 | % PlaceboN = 683 |
Autonomic Nervous | Accommodation abnormal | 2 | 1 |
Dry mouth | 35 | 10 |
General | Chest pain | 2 | 1 |
Fatigue | 4 | 3 |
Headache | 7 | 5 |
Influenza-like symptoms | 3 | 2 |
Central/Peripheral Nervous | Vertigo/dizziness | 5 | 3 |
Gastrointestinal | Abdominal pain | 5 | 3 |
Constipation | 7 | 4 |
Diarrhea | 4 | 3 |
Dyspepsia | 4 | 1 |
Urinary | Dysuria | 2 | 1 |
Skin/Appendages | Dry skin | 1 | 0 |
Musculoskeletal | Arthralgia | 2 | 1 |
Vision | Xerophthalmia | 3 | 2 |
Psychiatric | Somnolence | 3 | 2 |
Metabolic/Nutritional | Weight gain | 1 | 0 |
Resistance Mechanism | Infection | 1 | 0 |