A cold and cough lasting 4 days is typically viral. Levofloxacin is a strong antibiotic and is completely ineffective against viruses; taking it unnecessarily can cause adverse side effects and antibiotic resistance. You should stop taking Levofloxacin unless a doctor specifically prescribes it after confirming a bacterial infection. Montek LC can help reduce allergy-like symptoms like a runny nose or cough, but it won't cure a viral infection. For relief, focus on steam inhalation, warm fluids, and throat lozenges. Please consult a healthcare professional for a proper physical evaluation and appropriate treatment.