This medicine is usually taken with water on an empty stomach. However, your doctor may want you to take it with food or milk to lessen stomach upset.

Take this medicine only as directed. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

Dosing

The dose of oxybutynin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of oxybutynin. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage forms (syrup or tablets):
  • For treatment of bladder problems:
    • Adults and children 12 years of age and over 5 milligrams (mg) two or three times a day.
    • Children up to 5 years of age Use and dose have not been determined.
    • Children 5 to 12 years of age 5 mg two or three times a day. The dose is usually not more than 15 mg a day.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the tablet form of this medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep the syrup form of this medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For oxybutynin, the following should be considered:

Allergies Tell your doctor if you have ever had any unusual or allergic reaction to oxybutynin. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy Oxybutynin has not been studied in pregnant women. However, it has not been shown to cause birth defects or other problems in animal studies.

Breast-feeding Oxybutynin has not been reported to cause problems in nursing babies. However, since this medicine tends to decrease the secretions of the body, it is possible that the flow of breast milk may be reduced in some patients.

Children There is no specific information about the use of oxybutynin in children under 5 years of age. In older children, oxybutynin is not expected to cause different side effects or problems than it does in adults.

Older adults Elderly people are especially sensitive to the effects of oxybutynin. This may increase the chance of side effects during treatment.

Other medicines Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking oxybutynin, it is especially important that your health care professional know if you are taking any of the following:

• Amantadine (e.g., Symmetrel) or
• Anticholinergics (medicine for abdominal or stomach spasms or cramps) or
• Antidepressants (medicine for depression) or
• Antidyskinetics (medicine for Parkinson's disease or other conditions affecting control of muscles) or
• Antihistamines or
• Antipsychotics (medicine for mental illness) or
• Buclizine (e.g., Bucladin) or
• Carbamazepine (e.g., Tegretol) or
• Cyclizine (e.g., Marezine) or
• Cyclobenzaprine (e.g., Flexeril) or
• Disopyramide (e.g., Norpace) or
• Flavoxate (e.g., Urispas) or
• Ipratropium (e.g., Atrovent) or
• Meclizine (e.g., Antivert) or
• Methylphenidate (e.g., Ritalin) or
• Orphenadrine (e.g., Norflex) or
• Procainamide (e.g., Pronestyl) or
• Promethazine (e.g., Phenergan) or
• Quinidine (e.g., Quinidex) or
• Trimeprazine (e.g., Temaril) Taking oxybutynin with these medicines may increase the effects of either medicine

• Bleeding (severe) Oxybutynin may increase heart rate, which may make this condition worse

• Colitis (severe) or
• Dryness of mouth (severe and continuing) or
• Enlarged prostate or
• Glaucoma or
• Heart disease or
• Hiatal hernia or
• High blood pressure (hypertension) or
• Intestinal blockage or other intestinal or stomach problems or
• Myasthenia gravis or
• Toxemia of pregnancy or
• Urinary tract blockage or problems with urination Oxybutynin may make these conditions worse

• Kidney disease or
• Liver disease Higher blood levels of oxybutynin may occur, which increases the chance of side effects

• Overactive thyroid Oxybutynin may further increase heart rate