Tolterodine belongs to a group of medications known as antispasmodics and anticholinergics. It is used to treat people with overactive bladders who have symptoms including frequent urination, urgency, or involuntary loss of urine. Tolterodine helps these symptoms by preventing contractions or spasms of the bladder.

Relief from symptoms may not occur until about 2 weeks after starting treatment with tolterodine extended-release capsules, and maximum improvement may not be seen until after 8 weeks of treatment.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual recommended dose of tolterodine extended-release capsules is 4 mg once daily to start. The dose may later be reduced to 2 mg once daily based on individual response and needs. The maximum dose is 4 mg daily.

For people with reduced liver or kidney function, and people taking certain medications, the recommended dose is 2 mg once daily. Check with your doctor or pharmacist.

The capsules should be swallowed whole, not crushed or chewed. They can be taken with or without food.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

It is important to take this medication regularly and exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Tolterodine should not be taken by anyone who:

Tolterodine should not be taken by anyone who:

• is allergic to tolterodine or any of the ingredients of the medication
• has gastric retention (stomach obstruction)
• has uncontrolled narrow-angle glaucoma
• has urinary retention
• is allergic to tolterodine or any of the ingredients of the medication
• has gastric retention (stomach obstruction)
• has uncontrolled narrow-angle glaucoma
• has urinary retention

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• constipation
• dizziness
• dry eyes
• dry mouth
• fatigue
• headache
• heartburn
• vision changes, including difficulty adjusting to distances

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• bloody or cloudy urine
• difficult, burning, or painful urination
• swelling of the lower legs

Stop taking the medication and seek immediate medical attention if any of the following occur:

• symptoms of an abnormal heart rhythm such as dizziness, heart palpitations (fast, pounding or irregular heartbeat), fainting, or seizures
• symptoms of an allergic reaction (such as difficulty breathing, hives, swelling of the fact or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Abnormal heart rhythm: This medication may cause or increase the risk for a certain type of abnormal heart rhythm called QT prolongation. Other medications can also increase the risk of QT prolongation when taken together with tolterodine. This abnormal heart rhythm is more likely to occur in women, seniors, and people with certain risk factors such as:

• heart disease
• other heart rhythm problems (such as atrial fibrillation)
• a history of stroke
• a family history of sudden cardiac death
• blood electrolyte disturbances
• abnormally slow heartbeat
• eating disorders
• diabetes
• nerve disorders

If you experience symptoms of an abnormal heart rhythm such as dizziness, heart palpitations (fast, pounding, or irregular heartbeat), fainting, or seizures, stop taking this medication and get immediate medical attention.

Bladder problems: People with conditions that significantly block the bladder should be closely monitored by their doctor for urinary retention while taking this medication. If you experience difficulty urinating while taking this medication, contact your doctor.

Driving/using machinery: Tolterodine may cause fatigue, dizziness, or blurred vision. Avoid activities requiring mental alertness, such as driving, operating machinery, or performing hazardous work, if the medication affects you in this way.

Drowsiness/reduced alertness: This medication may cause dizziness, which may impair your ability to drive or operate machinery. Avoid hazardous tasks until you know how the medication affects you.

Glaucoma: People who have controlled narrow-angle glaucoma should discuss the benefits and risks of this medication with their doctor. Tolterodine may worsen this condition.

Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: People with liver disease may be more at risk of experiencing side effects and may require lower doses of this medication. Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

Myasthenia Gravis: If you have myasthenia gravis, tolterodine may make your symptoms worse. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Stomach problems: People with stomach problems affecting the passage and digestion of food should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you are or may be pregnant, talk to your doctor about the benefits and risks of using this medication. Women who may become pregnant should use adequate contraception (birth control) while taking this medication.

Breast-feeding: It is not known if tolterodine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between tolterodine and any of the following:

• aclidinium
• alpha blockers (e.g., alfuzosin, doxazosin, silodosin, tamsulosin)
• amantadine
• amiodarone
• amoxapine
• antihistamines (e.g., bilastine, cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine, rupatadine)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• aprepitant
• atropine
• "azole" antifungals (e.g., ketoconazole, fluconazole, voriconazole)
• benztropine
• botulinum toxin
• buprenorphine
• bupropion
• cannabis
• carbamazepine
• clidinium
• cobicistat
• conivaptan
• cyclobenzaprine
• darifenacin
• disopyramide
• diltiazem
• dimenhydrinate
• domperidone
• donepezil
• dronedarone
• eluxadoline
• fesoterodine
• flecainide
• formoterol
• galantamine
• glycopyrrolate
• grapefruit juice
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• ipratropium
• ketotifen
• letermovir
• macrolide antibiotics (e.g., erythromycin, clarithromycin,)
• methadone
• metoclopramide
• mifepristone
• mirabegron
• moclobemide
• nabilone
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone, tapentadol, tramadol)
• orphenadrine
• oxybutynin
• potassium chloride
• procainamide
• quinidine
• quinolone antibiotics (e.g., ciprofloxacin, moxifloxacin, ofloxacin)
• St. John's wort
• secretin
• serotonin antagonists (anti-emetics; granisetron, ondansetron)
• certain selective serotonin reuptake inhibitors (SSRIs; e.g., fluoxetine, paroxetine, sertraline)
• scopolamine
• solifenacin
• tacrolimus
• terbinafine
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
• tiotropium
• topiramate
• tranylcypromine
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• trospium
• tyrosine kinase inhibitors (e.g., lapatinib, pazopanib, sunitinib)
• umeclidinium
• venlafaxine
• verapamil
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.