Emerging clinical role of pivmecillinam in the treatment of urinary tract infection in the context of multidrug-resistant bacteria.

The continuing spread of resistant Gram-negative bacteria is a therapeutic challenge and prudent use of antimicrobials is therefore essential. Urinary tract infections (UTIs), usually due to Gram-negative bacteria, are among the most common infections seen in the community. Moreover, bacterial strains producing extended-spectrum β-lactamases (ESBLs) that are resistant not only to cephalosporins and penicillins, but also to fluoroquinolones and trimethoprim, are becoming more prevalent in the community. This means that oral antibiotic options to treat these infections are limited. The discovery of new drugs to tackle these problems has been difficult and slow paced; it is therefore timely to 'rediscover' the current antibiotics we have available in our clinical formulary, to determine how best they can be used. Pivmecillinam is an oral antibiotic with excellent clinical efficacy in the treatment of uncomplicated UTIs. It has been used extensively in Nordic countries with few problems, but, despite this, it is not widely used in other countries. There is emerging in vitro and in vivo evidence of its activity against ESBL-producing organisms and its synergistic potential with β-lactamase inhibitors. Pivmecillinam is well tolerated with a low side-effect profile. Pivmecillinam also has a minimal effect on the intestinal and vaginal flora of the host; thus, there is a lower rate of selection of resistant bacteria, vaginal candidiasis and, of note, Clostridium difficile.