Tazocin is a specific brand of the antibiotic piperacillin-tazobactam, of which generic formulations are also licensed for use. Tazocin is indicated for the treatment of a range of severe and complicated infections. As with all licensed medicines, the Medicines and Healthcare products Regulatory Agency (MHRA) has evaluated the safety, quality and efficacy of Tazocin in accordance with its licensed use and the balance of benefits and risks is favourable. The licensed recommendations on the use of Tazocin are described in the Summary of Product Characteristics (SmPC) for prescribers as well as the Patient Information Leaflet (PIL). The possible side effects of use in accordance with the licensed indications and dosages are also listed in the SmPC and PIL. As with any medicine, healthcare professionals are able to prescribe Tazocin ‘off-label’ at dosages that are not authorised in the SmPC. Off-label use is the responsibility of the prescriber, based on their clinical judgement and the benefits and risks to an individual patient. The MHRA does not issue guidance on the circumstances under which off-label use of Tazocin may be appropriate, nor has it conducted a study of mortality in patients following off-label use.