Oxybutynin is used to treat certain bladder and urinary conditions (such as overactive bladder). It relaxes the muscles in the bladder to help decrease problems of urgency and frequent urination. Oxybutynin belongs to a class of drugs known as antispasmodics.

Take this medication by mouth with or without food as directed by your doctor, usually 2 to 3 times a day. The dosage and length of treatment is based on your medical condition and response to treatment.

If you are using the liquid form of this medication, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

Use this medication regularly in order to get the most benefit from it. Remember to use it at the same times each day.

Tell your doctor if your condition lasts or gets worse.

Dry mouth, dizziness, drowsiness, blurred vision, dry eyes, nausea, vomiting, upset stomach, stomach pain, constipation, diarrhea, headache, unusual taste in mouth, dry/flushed skin, and weakness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

To relieve dry mouth, suck on (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water or use a saliva substitute. To relieve dry eyes, use artificial tears or other eye lubricants. Consult your pharmacist for further advice.

To prevent constipation, eat dietary fiber, drink enough water, and exercise. You may also need to take a laxative. Ask your pharmacist which type of laxative is right for you.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• decreased sexual activity
• difficulty urinating
• fast/pounding heartbeat
• signs of kidney infection (such as burning/painful/frequent urination, lower back pain, fever)
• mental/mood changes (such as confusion, hallucinations)
• swelling of arms/legs/ankles/feet
• vision problems (including eye pain)
• seizures
• stomach/intestinal blockage (such as nausea/vomiting that doesn't stop, prolonged constipation)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking oxybutynin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• glaucoma
• bladder disease (such as bladder outflow blockage, urinary retention)
• certain muscle disease (myasthenia gravis)
• heart disease (such as heart failure, coronary artery disease, arrhythmias)
• high blood pressure
• liver disease
• kidney disease
• loss of mental abilities (dementia)
• certain nervous system disorder (autonomic neuropathy)
• enlarged prostate gland (benign prostatic hypertrophy-BPH)
• stomach/intestinal disease (such as blockage, paralytic ileus, acid reflux disease, hiatal hernia, ulcerative colitis)
• overactive thyroid (hyperthyroidism)
• Parkinson's disease

This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This drug may increase the risk for heatstroke because it causes decreased sweating. Avoid becoming overheated in hot weather, saunas, and during exercise or other strenuous activity.

Older adults may be more sensitive to the side effects of this drug, especially drowsiness, confusion, constipation, trouble urinating. Drowsiness and confusion can increase the risk of falling.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• pramlintide
• drugs that can irritate the esophagus/stomach (such as potassium tablets/capsules, oral bisphosphonates including alendronate, etidronate)

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that can cause drowsiness, constipation or blurred vision. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: delirium and paralysis.

Do not share this medication with others.

If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.