The Flu is caused by the Rhinovirus. Antibiotics can only kill bacteria not viruses as viruses have different machinery to survive and replicate. Antibiotics have nothing to target in Viruses. Overuse of antibiotics will lead to the development of antibiotic resistance. Antibiotic resistance happens when the antibiotic kills bacteria that is causing infection as well as some other good bacteria. This allows the growth and development of few bacterial strains that are resistant to the antibiotic used. The drug-resistance gene can then be spread from one bacteria to the other.