Oxybutynin belongs to the family of medications called anticholinergics. It is also an antispasmodic. Oxybutynin is used to relieve symptoms associated with an overactive bladder, such as urinary urgency (a need to urinate right away), urinary frequency, leakage, or urge incontinence (leaking or wetting caused by an unstoppable urge to urinate).

This medication works by relaxing the muscles of the bladder. It helps to reduce bladder spasms, the urge to pass urine, and the frequency of urination.

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 starting dose of controlled release oxybutynin is 5 mg to 10 mg taken once daily, at the same time every day. Depending on the effectiveness and side effects of the medication, your doctor may increase your daily dose of this medication by 5 mg each week until an effective and well-tolerated dose is established. The maximum dose is 30 mg per day.

If you are already taking regular release oxybutynin, you doctor may switch you to oxybutynin controlled release at a higher dose than what is suggested here.

This medication may be taken with or without food.

Swallow this medication whole with water or other liquids. Do not crush, chew, or split the tablets.

This medication is contained in a special tablet that releases oxybutynin at a controlled rate. Do not be concerned if you notice something in your stool that looks like a tablet. This is just the tablet shell, which is left over after the medication is released in the body.

Many things can affect the dose of a 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 taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed. If you miss a dose of this medication, take it as soon as possible. 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 dose. 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 and protect it from light, moisture, and high humidity. Keep it out of the reach of children.

Do not take oxybutynin if you:

• are allergic to oxybutynin or to any of the ingredients of the medication
• have difficulty starting urine flow (urinary retention) or are at risk for this condition
• have intestinal atony (loss of tone of intestinal muscles) due to aging or debilitation
• have megacolon (dilated large intestine)
• have myasthenia gravis
• have narrow-angle glaucoma or are at risk for it
• have obstructive uropathy (blocked urine flow)
• have paralytic ileus (a condition that causes complete or partial blockage of the bowel)
• have partial or complete obstruction of the gastrointestinal tract or are at risk for it

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.

Although most of these 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:

• back or joint pain
• blurred vision
• confusion
• eye pain
• nervousness
• signs of heart rhythm disturbances such as dizziness or palpitations (sensation of rapid, pounding, or irregular heartbeat)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of urinary tract infection (e.g., burning when passing urine, blood in the urine, or increased urgency to urinate)
• swelling of the hands and feet
• symptoms of increased blood pressure (e.g., headache, vision problems, dizziness, shortness of breath)
• unusual weakness

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

• feeling agitated or behaving irrationally
• hallucinations
• seizures
• signs and symptoms of a severe allergic reaction (e.g., hives; itchy skin; difficulty breathing or swallowing; swelling of the face, throat, or tongue)
• symptoms of a severe skin reaction (e.g., rash, red skin, blisters, peeling, fever)

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.

Drowsiness/blurred vision: Oxybutynin may cause drowsiness or blurred vision. Avoid activities requiring mental alertness, such as driving, operating machinery, or performing hazardous work, while taking this medication until you are certain that your ability to perform these tasks is not impaired by oxybutynin. Alcohol and other medications that cause drowsiness may increase the drowsiness caused by oxybutynin.

Gastrointestinal disorders: Oxybutynin can worsen gastroesophageal reflux caused by hiatus hernia and can cause serious intestinal problems for people with ulcerative colitis. If you have a disorder involving the digestive system, 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.

Heart conditions: The symptoms of heart disease, heart failure, abnormal heart rhythms, and high blood pressure can be aggravated by oxybutynin. Also, oxybutynin may cause or worsen a heart rhythm problem called QT prolongation. If you are at risk of developing QT prolongation, your doctor will monitor you closely. If you experience symptoms such as dizziness, palpitations, or fainting, stop taking oxybutynin and seek immediate medical attention.

Heat stroke: Oxybutynin causes a decrease in sweating, which is one of the body's way of cooling off. When oxybutynin is taken during very hot weather, it can cause fever and heat stroke due to the body being unable to cool down enough. Take care not to overheat when you are taking this medication. Stay in a cool environment if possible, limit the length of time you spend outdoors, and drink plenty of water to reduce the risk of heat stroke.

Kidney function: 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: If you have reduced liver function or liver 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.

Prostate enlargement: The symptoms of prostate enlargement may be worsened by oxybutynin. If you have prostate enlargement or another problem involving the prostate gland, 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.

Thyroid problems: The symptoms of overactive thyroid may be worsened by oxybutynin. If you have an overactive thyroid, 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.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if oxybutynin 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.

Seniors: Seniors may be at increased risk of side effects when taking oxybutynin.

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

If you are taking any of these, 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. 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.