http://www.medications.com/effect/view/29704 Sinus infection and chest congestion: doctor knew I was on HCTZ, a diuretic, as well as Zyrtec and Nasonex. The HCTZ I now known is an agent that should have triggered a modification of the treatment protocol. First night on the 400 mg Avelox, during con Thu, 20 Nov 2008 09:25:17 -0500 http://www.medications.com/effect/view/29704?item=14680 Common side effects of Avelox are nausea, vomiting and diarrhea. Less common side effects of Avelox are abdominal pain, headache, rash, restlessness. Rare side effects of Avelox may include confusion, shortness of breath, blood in urine, coughing up blo http://www.medications.com/effect/view/29704?item=14680