Tolterodine: bladder urgency tablets and capsules

Tolterodine treats the symptoms of an overactive bladder: a sudden, urgent need to pass urine, needing to go more often than usual and involuntary leaking when you cannot reach a toilet in time. It is also used for bedwetting in children, known as nocturnal enuresis.

It is a prescription-only medicine sold as Neditol, Detrusitol and Mariosea. It relaxes the muscles of the bladder so that it can hold more liquid, which means you need to pass urine less often and less urgently.

Standard tablets are taken twice a day, with adults typically taking 2 mg in the morning and 2 mg in the evening, 12 hours apart. Slow-release capsules are taken once a day, typically 4 mg for adults, at the same time every day. A reduced dose, such as 1 mg twice daily or one 2 mg slow-release capsule daily, is used for people with kidney or liver disease or troublesome side effects. Children are prescribed 1 mg to 4 mg a day under specialist guidance, usually 1 mg at bedtime for bedwetting. Follow your prescriber.

Swallow tablets and capsules whole with water, with or without food. Slow-release capsules must not be chewed.

• It starts working within 3 to 6 hours but can take 4 weeks or longer to work fully.

• Treatment is long-term; your doctor reviews it after 4 weeks and then every 6 to 12 months.

• If you miss a dose, take it when you remember unless the next dose is close, in which case skip it. Never double up.

• Call 999 for a fast or irregular heartbeat, seizures or severe breathing problems after an overdose, and NHS 111 for any dose above what was prescribed.

Most adults aged 18 and over can take tolterodine, and children aged 2 and over under specialist guidance. Tell your doctor if you have had an allergic reaction to it; digestion problems, severe constipation, heartburn or acid reflux, hiatus hernia, or a severe stomach or bowel condition such as toxic megacolon; kidney or liver impairment; myasthenia gravis; dementia or cognitive impairment; autonomic neuropathy; angle closure glaucoma; heart conditions including long QT syndrome, heart failure, irregular or slow heartbeats or cardiomyopathy; trouble emptying the bladder or an enlarged prostate; or if you are pregnant, planning pregnancy or breastfeeding.

More than 1 in 100 people have dry mouth, headaches, dizziness, sleepiness or vertigo, diarrhoea, vomiting, wind or burping, stomach pain, dry eyes, blurred vision or problems passing urine. Sugar-free gum or sweets help dry mouth, eye drops help dry eyes, and if your vision is blurred do not drive, skip the next dose and speak to a doctor if it persists.

Call NHS 111 or a doctor for signs of faecal impaction (severe stomach pain, constipation and runny stools), difficulty emptying the bladder, signs of a urine infection such as fever, burning, back pain and cloudy or bloody urine, or swollen ankles, feet or legs. Call 999 for chest pain, severe breathing difficulty, swelling of the lips, mouth, throat or tongue, or collapse.

Suspected side effects can be reported through the Yellow Card scheme.

Tolterodine is not typically advised in pregnancy because of insufficient safety data. If your baby is healthy you can take it while breastfeeding if you need to, as the amount in milk is believed to be minimal. Watch for feeding changes, unusual behaviour, constipation, diarrhoea, vomiting or dry skin in the baby. There is no evidence it affects fertility.

The NHS names the antibiotics erythromycin and clarithromycin, the antifungals itraconazole and fluconazole, HIV medicines, the anti-sickness medicines metoclopramide, prochlorperazine and domperidone, the heart medicines amiodarone, sotalol, quinidine and procainamide, fesoterodine, phenothiazines, clozapine, haloperidol, benperidol, the dementia medicines donepezil, rivastigmine, galantamine and tacrine, the tricyclic antidepressants amitriptyline, imipramine and dosulepin, and sedatives. Paracetamol is safe to take with it.

Avoid alcohol when starting tolterodine or raising the dose because it amplifies drowsiness, and it may increase night-time toilet trips. Do not drive if you feel drowsy, dizzy or clumsy, or have blurred vision or trouble concentrating.

Reviews every 6 to 12 months partly reflect a possible increased risk of confusion and of dementia worsening in some people. You can eat normally, but cutting back on caffeine from tea, coffee, cola and energy drinks and managing fluid intake can help; pelvic floor muscle exercises and bladder training are listed as non-drug options.