Hi Mike-
Joe regularly takes Lasix, and when his fluid becomes a problem, he sometimes gets put on Zaroxolyn. He was just on it. But today's labs showed an elevated creatinine, so he will stop the Zaroxolyn. So you're right that it can be terrific, but it also has to be watched very carefully.
It's tricky for Joe because he can easily slip into kidney failure, so he has lots of lab work, and lots of medication adjustments. He had labs 6 days ago, labs again today, and will have another set done on Friday. It's a real pain, but that's what has to be done for him to keep him regulated.