Avoid giving this medicine to the child if he/she is allergic to any of the components in R-Cinex 600 Tablet 3's, or if he/she has acute liver disease, drug-induced liver disease if the child has experienced liver damage linked to rifampicin or isoniazid, or if the child is taking anti-fungal (voriconazole) or medicines for HIV infection (protease inhibitors). R-Cinex 600 Tablet 3's may cause liver damage; consult your doctor if the child experiences symptoms such as unexplained loss of appetite, nausea, vomiting, jaundice, dark urine, persistent fatigue for more than 3 days, abdominal pain and tenderness. Consult a doctor if your child gets flu-like symptoms such as headache, fever, or muscle ache. Inform the doctor if your child has HIV infection, epilepsy, psychiatric disorder, diabetes, porphyria, phenylketonuria (metabolic disorder), peripheral neuropathy (tingling sensation in hands and feet), kidney or liver problems, if your child is allergic to ethionamide or niacin (nicotinic acid), or if your child is taking cortisone or any cortisone-like drug.