While minor, some of these side effects may occur. They are as follows; Upset stomach, heartburn, nausea, menstrual changes, or headache may occur. However if any of these persist or worsen, it’s best to speak with your doctor right away.
This medication may cause urine, sweat, saliva, or tears to change color (yellow, orange, red, or brown). This effect is harmless and will go away when the medication is stopped. However, teeth and contact lens staining may be permanent.
Rifampin may rarely cause serious liver disease. Though sometimes necessary to completely treat certain infections, combination treatment with other drugs (e.g., isoniazid, pyrazinamide) may increase this risk. Tell your doctor right away if you develop symptoms of liver disease, including: persistent nausea/vomiting, stomach/abdominal pain, dark urine, yellowing eyes/skin.
Tell your doctor right away if you have any serious side effects, including: signs of kidney problems (such as change in the amount of urine), mental/mood changes (such as confusion, unusual behavior), unusual tiredness, easy bruising/bleeding, small red spots on the skin, joint pain/swelling.
This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a type of resistant bacteria. This condition may occur during treatment or weeks to months after treatment has stopped. Do not use anti-diarrhea or opioid medications if you have any of the following symptoms because these products may make them worse. Tell your doctor right away if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool.
Use of this medication for prolonged or repeated periods may result in oral thrush or a new yeast infection (oral/vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.
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: fever that doesn't go away, new or worsening lymph node swelling, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.