Hi Furosemide may sometimes cause adverse effects like - loss of appetite, dry mouth, drowsiness, restless feeling, confusion, nausea, vomiting, increased urination, muscle pain or weakness, fainting, or seizure (convulsions), headache, trouble concentrating, weakness, ringing in your ears, short of breath, rapid heart rate, trouble concentrating, blurred vision, etc.,. This does not mean Abnormal LifeStyle Changes. If it happens in your friend, you must exclude Anxiety states or Depression as these may happen because of increasing tension due to his illness itself. Regards Ranjit