Certain side effects are seen frequently with this drug, many of which are mild to moderate. These include anemia, atrial fibrillation or heart murmur, constipation, diarrhea, nausea and vomiting. Other side effects include edema or swelling, thirst, pneumonia, urinary tract infections, depression and headache as well as change in blood pressure, insomnia and hypokalemia. If any of these side effects are experienced, it should be reported to a doctor immediately to adjust dosage for tolerance.