Abstract

Methenamine mandelate (Mandelamine - Warner), a combination of methenamine and mandelic acid, is promoted as a broad-spectrum antibacterial agent that can be used against chronic or recurrent urinary infections without the appearance of resistant strains. In the urine, the drug yields formaldehyde and mandelic acid, both of which act only in the urine and not at all in the tissues of the urinary tract. Mandelic acid has less antibacterial effect than formaldehyde, but causes some acidification of the urine. Each component requires a pH of 5. 5 or less in the urine for even moderate antibacterial activity, and a supplementary acidifying agent is usually necessary.