Drug Interactions between desmopressin and dihydrocodeine / phenylephrine

Dihydrocodeine can sometimes enhance the effects of desmopressin. Although not common, this may increase the risk of developing water retention and a condition known as hyponatremia, which is caused by an abnormal decrease in blood sodium concentration. In serious cases, hyponatremia can lead to seizure, coma, or even death. You should seek immediate medical attention if you experience loss of appetite, nausea, vomiting, drowsiness, fatigue, weakness, headache, confusion, difficulty concentrating, memory impairment, decreased urination, and/or sudden weight gain, as these may be early signs and symptoms of water intoxication and hyponatremia. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.