Abstract : Antibiotics are chemical substances derived from living organisms that can hamper the life cycle of other organisms. Ampicillin belongs to the penicillin group of β-lactam antibiotics and has broad- spectrum activity. Ampicillin has been used extensively to treat bacterial infections for a long and it is one of the highly prescribed antibiotics. Cloxacillin is a semisynthetic antibiotic in the same class as penicillin which is active against penicillinase-producing staphylococci as well as other gram-positive pathogens. Antibacterial drugs are also used commonly as a fixed-dose combination. The use of a fixed-dose combination of antibiotics is more common in developing countries. Ampicillin has also been used in combination with other antimicrobials, β-lactamase inhibitors such as Cloxacillin to improve its efficacy, broaden antimicrobial coverage and reduce the development of drug resistance. This combination demonstrates synergistic effect and helpful in the real-world treatment of a wide range of complicated infections including aerobic, anaerobic, and mixed infections. It is also utilized for the treatment of resistant infections, and for veterinary purposes. The synergistic effect of ampicillin and cloxacillin combination may be useful in those ampicillin-resistant strains as well as where the broader antibacterial coverage required. Real-world evidence required for its resurgence and effective antibacterial therapeutic alternative where a broad spectrum of antibiotics may consider future use and to avoid the further resistance.