Dizziness, drowsiness, blurred vision, dry mouth, headache, trouble sleeping, constipation, flushing, dry skin, and decreased sweating may occur. If any of these effects last or get worse, notify 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. An empty medication 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: mental/mood changes (such as confusion, unusual excitement), fast/irregular heartbeat, difficulty urinating, decreased sexual ability, loss of coordination, trouble speaking, vomiting. Get medical help right away if you have any very serious side effects, including: eye pain/swelling/redness, vision changes (such as seeing rainbows around lights at night). 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.
Some products that may interact with this drug are: certain azole anti-fungal drugs (ketoconazole, itraconazole), bisphosphonate drugs (such as alendronate, risedronate), corticosteroids (such as prednisone), digoxin (slow-dissolving tablets), potassium tablets/capsules, pramlintide. 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 cause drowsiness. Ask your pharmacist about using those products safely. This medication may interfere with certain lab tests, possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.