Prolonged Lasix Use

[CKD83]

I am a retired horse jockey for 7 years now. I raced professionally and had to maintain a certain weight. It got to a point, where i just couldn't shed the last 3 to 4 pounds so I was introduced to the use of Lasix (furosemide). It was accessible for me to purchase a large bottle of the liquid form from a vet on the track and so fir a couple of years I would take 1cc to 2cc, depending on the number of pounds I wanted to lose. I would add it to a small amount of Orange Juice and drink it down. In the next 2 to three hours I was able to lose 3 to 6 lbs if water weight and make weight in time to stand on the scale on race day. In general, I was young, selfish, and willing to do anything for the thrill of being on a horse going 35mph. I did this 2 to 3 times a week for 2 years. Since I quite racing, I stopped using it. I have since had a kidney stone 3 years ago. I am currently battling hives that no dermatologist nor allergist understand. I do take levothyroxine for hypothyroidism. I do not feel that I have any symptoms of kidney problems,  but could I get hives from this long term, heavy use of Lasix? I've never spoken of this to a doctor.