Dry mouth, drowsiness, headache, dizziness, nausea, vomiting, upset stomach, stomach pain, constipation, diarrhea, blurred vision, dry eyes, unusual taste in mouth, dry/flushed skin, stuffy nose, and cough 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.For certain products of this drug, an empty tablet shell may appear in your stool. This is harmless.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.