Patients who have been exposed to tuberculosis might take isoniazid. This medication is an antibiotic that kills active tuberculosis bacteria. It may be prescribed in conjunction with other tuberculosis medications. Patients often have to take this medication for a long period of time to ensure that tuberculosis is completely eliminated from their systems.
This medication can cause serious damage to patients’ livers. Patients who have a history of alcoholism or who have had liver disease in the past are at greater risk for liver problems while on this medication than other patients. Call your doctor immediately if you have severe stomach pain, jaundice, nausea and vomiting, brown urine, tarry black stools and loss of appetite.