IMPACT is a reference guide for medical professionals to assist them in the appropriate use of antimicrobial drugs. It was developed by the Antimicrobial Resistant Project Office (ARPO), an organization under the Health and Medical Council of the Government of Hong Kong. The guideline was intended for health professionals in Hong Kong and is applicable to both inpatients and outpatients.

The guideline is based on the latest scientific evidence and data from local studies. It provides clinical guidance on the treatment of different infections and the use of different classes of antimicrobials.

It also contains information on the recommended dosages and durations of different treatments, as well as the appropriate use of prophylaxis and precautions for patients with a history of penicillin or cephalosporin allergy.