Isonij 300mg Tablet is an antibiotic used for the treatment and prevention of tuberculosis (TB) and inactive (latent) TB (a serious infection caused by bacteria that affects the lungs and in certain cases other parts of the body). It works by killing the bacteria that cause tuberculosis. Isonij 300mg Tablet should be used in the dose and duration as advised by your doctor. It is to be taken on an empty stomach. Do not skip any doses and finish the full course of treatment even if you feel better. Stopping it early can result in treatment failure and increase the side effects too. Do not take a double dose to make up for a missed dose. Simply take the next dose as planned. Some common side effects of this medicine include tingling and numbness of feet and hand (peripheral neuropathy). Inform your doctor if you notice signs of jaundice, i.e., yellowing of eyes or skin, dark urine, stomach pain, or joint pain. You may also develop hepatitis (viral infection of the liver) or increased liver enzymes as side effects of this medicine. Please consult your doctor, as these side effects require medical attention and need dose modification. Your doctor may monitor your liver function while on treatment with this medicine. Avoid drinking alcohol as this may have additional adverse effects on the liver. Pregnant or breastfeeding women should consult their doctor before using this medicine.