Headache, diarrhea, nausea, gas, stomach pain, constipation, or dry mouth may occur. If any of these effects persist or worsen, notify 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 immediately if any of these unlikely but serious side effects occur: signs of a lung infection called pneumonia (e.g., fever, cough, trouble breathing).
Tell your doctor immediately if any of these rare but very serious side effects occur: severe stomach/abdominal pain, persistent nausea, vomiting, unusual tiredness, dark urine, yellowing eyes/skin, signs of vitamin B-12 deficiency with long-term (over 3 years) treatment (e.g., unusual weakness, sore tongue, numbness or tingling of the hands/feet).
A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching, swelling, 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.