Do not take Nitib 140mg Tablet 30's if you are allergic to any of its components, if you are taking St. John's wort (herbal medicine) or if you are pregnant/breastfeeding. Inform the doctor if you have/had unusual bruising or bleeding, irregular heartbeat, heart failure, hepatitis B infection, liver problems, high blood pressure, kidney problems, or if you are due to undergo any surgery. Seek immediate medical attention if you experience symptoms of progressive multifocal leukoencephalopathy, a serious brain infection (trouble thinking, memory loss, sight loss, or difficulty walking), stroke (sudden confusion, numbness or weakness, trouble speaking, sight loss, loss of balance, or sudden severe headache), heart failure (breathlessness, difficulty breathing when lying down, weakness/tiredness, or swelling of the feet, ankles, or legs), rupture of the spleen (left abdominal pain, pain below the left rib cage or at the tip of left shoulder), infection (chills, fever, weakness, body aches, cold, flu symptoms, or confusion), or haemophagocytic lymphohistiocytosis, an inflammatory disorder (fever, bruising, swollen glands, or skin rash).