Urinary concentrations and urine ex-vivo effect of mecillinam and sulphamethizole

Clin Microbiol Infect. 2004 Jan;10(1):54-61. doi: 10.1111/j.1469-0691.2004.00737.x.


Healthy adult volunteers received 1 g of sulphamethizole orally (n = 10) and later 400 mg of pivmecillinam (274 mg of mecillinam) (n = 9). All urine was collected in defined periods over 24 h, and the drug concentrations in urine were determined. For sulphamethizole, the maximum urine concentration for seven subjects was reached in 0-3 h, and for the remaining three in 3-6 h. For mecillinam, eight of the nine subjects attained a maximum urine concentration in 0-3 h, after which the concentration declined rapidly for six subjects in 3-6 h. Strains of Escherichia coli with different MICs for sulphamethizole and mecillinam were exposed to collected urine for 2.5 h and 5 h. The results indicated that a sensitive E. coli population should be suppressed by sulphamethizole in urine for two-thirds of the time (with 1 g twice-daily) and by mecillinam in urine throughout the 24-h period (with 400 mg three times a day). There was a slight but significant correlation between the ex-vivo effect (Delta log10 CFU/mL) and the log10 concentration/MIC ratio after exposure to sulphamethizole for 5 h (r2 = 0.27, p < 0.0001), and a significant correlation between the variables with mecillinam (r2 = 0.66, p < 0.0001).

MeSH terms

  • Administration, Oral
  • Amdinocillin / administration & dosage
  • Amdinocillin / pharmacology*
  • Amdinocillin / urine*
  • Drug Resistance, Bacterial
  • Escherichia coli / drug effects*
  • Escherichia coli Infections / microbiology
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests / methods
  • Microbial Sensitivity Tests / standards
  • Middle Aged
  • Sulfamethizole / administration & dosage
  • Sulfamethizole / pharmacology*
  • Sulfamethizole / urine*
  • Urinary Tract Infections / microbiology*


  • Sulfamethizole
  • Amdinocillin