Detrusitol

Detrusitol contains tolterodine tartrate, an antimuscarinic (anticholinergic) medication used for the symptomatic treatment of urinary urgency, frequency, and urge incontinence associated with overactive bladder syndrome (OAB).

It is one of the most widely prescribed bladder-calming agents in clinical practice.

Overactive bladder is characterised by involuntary contractions of the detrusor muscle during the filling phase of the bladder cycle, leading to a sudden and compelling need to urinate.

Tolterodine works by blocking muscarinic receptors on the detrusor muscle, reducing the frequency and intensity of these unwanted contractions and increasing the functional capacity of the bladder.

Tolterodine has relative selectivity for bladder muscarinic receptors compared with salivary gland receptors, which means it tends to cause less dry mouth than some older antimuscarinic agents such as oxybutynin.

It is available in both immediate-release and extended-release (XL) formulations.

Detrusitol is typically prescribed after conservative measures such as bladder training, fluid management, and pelvic floor exercises have been attempted.

Patients may also benefit from combining drug therapy with ongoing behavioural strategies.

For immediate-release tablets: take one 2 mg tablet twice daily, with or without food. For the extended-release capsule (Detrusitol XL): take one 4 mg capsule once daily, swallowed whole with water.

Do not crush or chew the extended-release capsule.

Take the medication at the same time(s) each day. Continue treatment for as long as your prescriber recommends.

If symptoms do not improve after four to eight weeks, a review of treatment is advisable.

Reduce your intake of caffeine and alcohol, as these can aggravate bladder symptoms. Maintain an adequate fluid intake of around 1.5 litres daily to prevent urinary tract infections.

Immediate-release: 2 mg twice daily. This may be reduced to 1 mg twice daily if side effects are troublesome. Extended-release: 4 mg once daily, reducible to 2 mg once daily if required.

In patients with significant hepatic impairment or severe renal impairment (GFR below 30 mL/min), the dose should be reduced to 1 mg twice daily (immediate-release) or 2 mg once daily (extended-release).

Dose reduction is also recommended when tolterodine is co-administered with potent CYP3A4 inhibitors.

Dry mouth is the most common side effect, reported in roughly 20 to 30 per cent of patients on immediate-release tolterodine.

The extended-release formulation is associated with a lower incidence (approximately 12 per cent). Constipation, dyspepsia, abdominal pain, and headache are also reported commonly.

Dry eyes, blurred vision, and dizziness may occur.

Urinary retention, although paradoxical for a bladder medication, can happen if the bladder muscle is excessively relaxed, particularly in men with prostatic enlargement.

Cognitive effects, including confusion and memory impairment, are a concern in elderly patients. Hallucinations have been reported rarely.

Tachycardia and peripheral oedema are uncommon cardiovascular effects.

Allergic reactions, including angioedema, are rare.

Use Detrusitol with caution in elderly patients, who are at higher risk of cognitive impairment and falls.

Antimuscarinics may worsen pre-existing cognitive decline and should be avoided or used at the lowest dose in patients with dementia.

Detrusitol is not suitable for patients with urinary retention, severe gastrointestinal obstruction, uncontrolled narrow-angle glaucoma, or myasthenia gravis.

Patients with a history of QT prolongation should be monitored, as tolterodine may prolong the QT interval at high doses.

Inform your prescriber of all other medications you are taking, particularly other anticholinergic drugs, as cumulative effects can be significant.

Detrusitol is contraindicated in patients with urinary retention, uncontrolled narrow-angle glaucoma, myasthenia gravis, severe ulcerative colitis, toxic megacolon, or known hypersensitivity to tolterodine or fesoterodine.

It should not be used in patients with severe hepatic impairment (Child-Pugh class C). Caution is required in patients with significant renal impairment.