Prothiaden M 50 Tablet is used in the treatment of depression. It contains Dosulepine and Methylcobalamin, which increase neurotransmitter (serotonin and noradrenaline) activity in the brain that regulates mood, memory, and the ability to concentrate. It may cause common side effects, such as dry mouth, blurred vision, headache, increased or decreased appetite, nausea or vomiting, diarrhoea, changes in heartbeat, constipation, difficulty urinating, and sweating. Before taking this medicine, you should tell your doctor if you are allergic to any of its components or if you are pregnant/breastfeeding, and about all the medications you are taking and pre-existing medical conditions.