Drowsiness, dizziness, lightheadedness, tiredness, upset stomach, or headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
This medication may rarely cause your urine to turn orange or reddish-purple. This effect is harmless and will disappear when the medication is stopped.
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: confusion, black/bloody stools, vomit that looks like coffee grounds, easy bruising/bleeding, signs of infection (such as sore throat that doesn't go away, fever).
This medication may rarely cause very serious (possibly fatal) liver disease. Stop taking this medication and get medical help right away if you develop symptoms of liver disease, including: nausea/vomiting that doesn't stop, stomach/abdominal pain, yellowing eyes/skin, dark urine.
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 MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.