TOLTERODINE
Clinical safety rating: safe
Animal studies have demonstrated safety
Competitive antagonist of muscarinic acetylcholine receptors (M1, M2, M3, M4, M5), with selectivity for the M3 receptor subtype involved in detrusor muscle contraction, reducing bladder smooth muscle contractility and increasing bladder capacity.
| Metabolism | Extensively metabolized in the liver via cytochrome P450 2D6 (CYP2D6) to its active metabolite 5-hydroxymethyl tolterodine; also metabolized via CYP3A4 to a lesser extent. Further metabolism via dealkylation and conjugation. |
| Excretion | Primarily hepatic metabolism via CYP2D6 and CYP3A4; renal excretion accounts for <5% of unchanged drug; ~80% excreted in urine as metabolites, ~20% in feces. |
| Half-life | Terminal elimination half-life is 2-4 hours in extensive CYP2D6 metabolizers; increased to 4-10 hours in poor metabolizers or with CYP3A4 inhibitors. |
| Protein binding | Plasma protein binding is >96% (primarily alpha-1-acid glycoprotein and albumin). |
| Volume of Distribution | Vd is approximately 1.0-1.3 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral bioavailability is 10-30% due to extensive first-pass metabolism; Extended-release formulation has lower peak concentrations but similar overall exposure. |
| Onset of Action | Immediate-release: 30-60 minutes; Extended-release: 2-4 hours. |
| Duration of Action | Immediate-release: 5-6 hours; Extended-release: 12-24 hours, allowing once-daily dosing. |
2 mg PO twice daily; may reduce to 1 mg twice daily if tolerated.
| Dosage form | TABLET |
| Renal impairment | For GFR < 30 mL/min: 2 mg PO once daily or 1 mg twice daily. |
| Liver impairment | Child-Pugh Class B or C: 1 mg PO twice daily; avoid use in severe impairment. |
| Pediatric use | Not approved; safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment; start at 2 mg once daily in frail elderly. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Strong CYP3A4 inhibitors may increase levels Can cause blurred vision and urinary retention.
| Breastfeeding | Excreted in animal milk; no human data. M/P ratio unknown. Caution advised; consider alternative therapies. |
| Teratogenic Risk | Pregnancy Category C. First trimester: No adequate human studies; animal studies show fetal resorption and skeletal abnormalities at high doses. Second and third trimesters: Potential risk due to anticholinergic effects; use only if benefit outweighs risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Common Effects | Dry mouth |
| Serious Effects |
Urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, known hypersensitivity to tolterodine or any inactive ingredient.
| Precautions | May cause urinary retention, particularly in patients with bladder outflow obstruction; may cause decreased gastrointestinal motility (use caution in patients with severe constipation, ulcerative colitis, myasthenia gravis); may cause angioedema; may cause CNS effects (e.g., dizziness, somnolence) and worsen cognitive impairment; caution in patients with hepatic impairment (dose reduction for moderate impairment); caution in patients with renal impairment; may exacerbate narrow-angle glaucoma; avoid use in patients with known hypersensitivity. |
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| Monitor maternal heart rate, blood pressure, and urinary function for anticholinergic effects. Fetal should be monitored for tachycardia and decreased amniotic fluid if used long term. |
| Fertility Effects | In animal studies, no significant impact on fertility observed. No human data on reproductive capacity. |