What are the side effects of Cetapin? The most commonly reported side effects when taking Cetapin XR tablets 500mg include: gastrointestinal symptoms (such as diarrhoea, nausea, vomiting) which are usually mild and resolve spontaneously during continued treatment, metallic taste in the mouth and skin rash. A rare and potentially life threatening side effect is lactic acidosis (a build-up of lactic acid in the blood) that can occur due to accumulation of metformin, particularly if you are taking high doses of metformin above 2000mg per day, have kidney problems, drink excessive amounts of alcohol, are elderly. When should Cetapin not be used? You should not use Cetapin XR tablets 500mg if you: are allergic to metformin or any other biguanide or any ingredients in Cetapin 500mg, are pregnant or are breastfeeding without discussion with your doctor have liver or kidney disease, have a conditions affecting renal function, like dehydration, severe infection or shock have diabetic ketoacidosis, diabetic precoma, have acute or chronic disease which may cause tissue hypoxia such as heart failure, recent myocardial infarction, respiratory failure, pulmonary embolism, shock, acute significant blood loss, sepsis, gangrene, pancreatitis, have a history of lactic acidosis, have a problem with alcohol, are undergoing radiological treatment with intravascular iodinated contrast agents which may lead to renal failure, resulting in metformin accumulation and a risk of lactic acidosis, are taking medications that may interact with Cetapin including: cimetidine for reflux and ulcers, medications for high blood pressure and heart conditions like nifedipine, beta-blockers, diuretics, other diabetes medications like sulfonylureas, corticosteroids such as prednisone, cortisone, anticoagulants |