Nervousness, shaking (tremor), headache, nausea or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.Remember that your doctor has prescribed this medication because he or she 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: fast/pounding heartbeat.Get medical help right away if you have any rare but very serious side effects, including: chest pain, irregular heartbeat, rapid breathing, confusion.Rarely, this medication has caused severe (rarely fatal), sudden worsening of breathing problems/asthma (paradoxical bronchospasm). If you experience sudden wheezing, get medical help right away.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.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.