Before taking tolterodine, 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.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: problems emptying your bladder (urinary retention), severe blockage of stomach/intestines (gastric retention), a certain eye condition (uncontrolled narrow-angle glaucoma).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: other bladder problems (e.g., bladder outflow obstruction), stomach/intestinal disease (e.g., ulcerative colitis), slowed movement of stomach/intestines, severe constipation, controlled narrow-angle glaucoma, kidney disease, liver disease, enlarged prostate, a certain muscle disease (myasthenia gravis).

Tolterodine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using tolterodine, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using tolterodine safely.

This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages.

This medication can cause decreased sweating. Avoid becoming overheated in hot weather, saunas, or during exercise or other strenuous activities since heatstroke may occur.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be more sensitive to this drug.

This medication should be used only when clearly needed during pregnancy. It is not known whether Detrol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Get emergency medical help if you have any of these signs of an allergic reaction to Detrol: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using Detrol and call your doctor at once if you have any of these serious side effects:

• chest pain, fast or uneven heart rate;
• confusion, hallucinations;
• urinating less than usual or not at all; or
• painful or difficult urination.

Less serious Detrol side effects may include:

• dry mouth, dry eyes;
• blurred vision;
• dizziness, drowsiness;
• constipation or diarrhea;
• stomach pain or upset;
• joint pain; or
• headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.