Tell your doctor your medical history, especially of: liver disease, kidney disease, allergies (especially drug allergies). To avoid dizziness or fainting, get up slowly from a lying or seated position (especially when you first start using this drug or if your doctor changes your dosing). Limit your intake of alcohol and avoid getting overheated because they may increase the dizziness and drowsiness effects of this drug. Use caution performing tasks requiring alertness such as driving or using machinery.

Dizziness, drowsiness, headache, constipation, loss of appetite, fatigue, nasal congestion or dry eyes may occur the first several days as your body adjusts to the medication. If any of these effects persist or worsen, notify your doctor promptly. Tell your doctor immediately if you have any of these unlikely but serious side effects: chest pain, swelling of the hands or feet, ringing in the ears. Males - though it is unlikely to occur, if you get a painful, prolonged erection, stop using this drug and seek immediate medical attention. Tell your doctor immediately if you have any of these highly unlikely but serious side effects: decreased sexual ability, easy bleeding or bruising, irregular or unusually fast heartbeat. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.

It is important to have your blood pressure checked regularly while taking this medication. Learn how to monitor your blood pressure. Discuss this with your doctor or pharmacist.