An audit of restricted antibiotic use in a general hospital.

An audit of the use of antibiotics restricted by the hospital formulary was undertaken by retrospective analysis of 73 written justifications for prescriptions provided to the pharmacy and the case notes. Half of the prescriptions were for therapeutic indications with the remainder divided almost equally between prophylactic and empirical use. The cost of therapy was $34,500. Antibiotic use was classified as appropriate or inappropriate. Inappropriate use was seen in 22 cases at an excess cost of $3828. Prophylactic use accounted for 13 of the inappropriate prescriptions, most frequently due to excessive duration of prescription. The use of amikacin where gentamicin was not contraindicated was seen in 4 of 9 inappropriate prescriptions. The infrequent use of the more expensive antibiotics and the potentially remediable inappropriate use seen with prophylaxis were gratifying aspects of this audit.