Avelox is an antibiotic prescribed to treat sinus and lung infections caused by bacteria like sinusitis and pneumonia. It works by killing bacteria but not viruses. Common side effects include skin rash, tingling, hives, and shortness of breath, while rare side effects include an allergic reaction. When taking Avelox, patients should drink plenty of water, avoid driving or operating machinery if dizzy, limit sun exposure, and wear protective clothing and sunscreen if outside to prevent dehydration and sun sensitivity.