Procedural compliance and clinical outcome associated with therapeutic interchange of extended-spectrum penicillins.

The degree of procedural compliance and the clinical outcome associated with a therapeutic interchange of extended-spectrum penicillins were assessed. Pharmacists conducted a concurrent chart review on all patients receiving mezlocillin as a therapeutic alternative for piperacillin or ticarcillin over a five-month period. The pharmacists assessed whether (1) the pharmacy appropriately dispensed mezlocillin when orders were written for piperacillin or ticarcillin, (2) physicians and nurses were properly notified of the therapeutic interchange, and (3) the bacterial isolates were susceptible to mezlocillin. Pharmacists and physicians evaluated clinical outcomes of all patients receiving mezlocillin through a retrospective chart review and classified the responses as "success," "failure," or "indeterminate." Fifty-one orders for piperacillin were written during the study period, and mezlocillin was selected as a therapeutic alternative in all cases. No orders for ticarcillin were written. Proper notification was made to nurses and physicians in 98% and 65% of cases, respectively. No mezlocillin-resistant gram-negative bacteria were found. Eighty-three courses of therapy were reviewed for clinical outcome; 68 were classified as successes, 0 were failures, and 15 were indeterminate. The cost savings after nine months of therapeutic interchange of mezlocillin for piperacillin was $6600. This study indicates that the pharmacy made a proper therapeutic interchange of mezlocillin for piperacillin and followed the correct procedure for notification of the nursing staff. However, more effort is needed to ensure communication with the prescribing physicians.

Prospective randomized comparison of mezlocillin therapy alone with combined ampicillin and gentamicin therapy for patients with cholangitis.

Forty-six patients with cholangitis were randomized to receive therapy with mezlocillin sodium (24 patients) or a combination of ampicillin sodium--gentamicin sulfate (22 patients). The biliary concentration of mezlocillin was 112 times higher than that of ampicillin and 778 times higher than that of gentamicin. The ratio of the concentration in serum or bile over the minimum inhibitory concentration against aerobic gram-negative bacilli (therapeutic index) was higher for mezlocillin than for either ampicillin or gentamicin. Twenty (83%) of 24 patients were cured following mezlocillin therapy compared with 9 (41%) of 22 patients after ampicillin-gentamicin therapy. The 3 patients with superinfection were in the ampicillin-gentamicin arm of the study. Fewer toxic or adverse effects occurred in association with mezlocillin treatment than with ampicillin-gentamicin treatment. Mezlocillin therapy was more effective, less toxic, and less expensive than treatment with ampicillin and gentamicin for patients with cholangitis.