Prescription of antibiotic treatment is complex. While most patients with fever do not require antibiotic treatment, early administration of appropriate antibiotics to patients with certain bacterial infections improves survival. Antibiotic use leads to bacterial resistance. Antibiotics can thus be justified only when truly needed. The narrowest spectrum antibiotic should be used to prevent resistance development to the more advanced antibiotics. However, the pathogen(s) causing infections become known only after 24-72 hours of infection onset and at many times are not isolated at all.