Metabolization
Siofor® is excreted unchanged via the kidney and thus in the urine. It is therefore important to have the laboratory values of the kidneys (here: especially the serum creatinine) determined on a regular basis in order to be able to adjust the dosage in good time if kidney function is impaired or to be able to switch to another drug if necessary.
Contraindication
Siofor® should not be taken in cases of hypersensitivity to the active ingredient metformin. Other contraindications for which Siofor® should not be taken include kidney function disorders or kidney failure, a recent heart attack and liver failure. Severe infections, shock or the administration of iodine-containing contrast media in certain examinations prohibit the use of this antidiabetic. During pregnancy and the subsequent breastfeeding period, as with many other drugs, the prescription of Siofor® should be avoided.
Side effects
A rare, but serious and very feared side effect is the so-called lactic acidosis. It is a serious complication affecting the metabolism, which leads to an accumulation of the active substance metformin in the body. Symptoms can include deep breathing (also known as “acidotic dyspnoea”), as well as complaints in the gastrointestinal tract with nausea and abdominal pain and a lowered temperature.
In the further course of the disease a comatose state may occur. Very rarely skin reactions or an inflammation of the liver may also occur, but these symptoms will recede once the medication is discontinued. More often, however, taste disorders occur. At the beginning of the therapy, patients often feel nausea, which can be accompanied by vomiting and diarrhea, as well as loss of appetite. However, these symptoms usually disappear again with the duration of the medication.
Interactions
Interactions occur when Siofor® is taken with alcohol, for example. This increases the risk of developing lactate acidosis. There is also an increased risk when metformin and iodine-containing contrast medium are administered simultaneously for certain examinations.For these examinations, Siofor® (metformin) should therefore be discontinued 42 hours beforehand and should not be taken again until 42 hours after the examination. The same precautions apply to planned operations.