I have used baytril many many times over the last 20+ years of keeping chameleons and have never had a problem with it. I have had trouble with amikacin though.
Perhaps its the dosage? I found this site and I don't know if it would apply to chameleons as well....
"No clinical signs of toxicity were observed when a dose of 5 mg/kg was administered for 15 days. Clinical signs of depression, incoordination, and muscle fasciculation were observed in calves when doses of 15 or 25 mg/kg were administered for 10 to 15 days. Clinical signs of depression, inappetence, and incoordination were observed when a dose of 50 mg/kg had been administered for 3 days"...
http://vetdrugslist.net/baytril-100...antimicrobial-injectable-solution/341115.html