| Abstract: | ![]()
The phagocytosis of killed Staphylococcus epidermidis by neutrophilic leukocytes was inhibited in vitro by indomethacin in a concentration of 3 × 10-4M, and by hydrocortisone, phenylbutazone, and paracetamol in a concentration of 10-3M. Phagocytosis was slightly stimulated by 10-7M phenylbutazone. Acetylsalicylic acid, mefenamic acid, and phenacetin had no effect. The bactericidal activity of leukocytes against live Staphylococcus epidermidis was reduced by 10-4M phenacetin, 5 × 10-4M mefenamic acid, and 10-3M phenylbutazone and indomethacin, whereas concentrations of 10-5M and above of paracetamol enhanced bacterial killing by leukocytes. Hydrocortisone and acetylsalicylic acid were ineffective. It is probable that concentrations of anti-inflammatory agents sufficient to affect phagocytosis and bacterial killing by neutrophils are as a rule not attained in the organism during treatment, although inhibition may occur locally, for example in inflamed tissue, as a consequence of a low pH, which potentiates the effect of acid anti-inflammatory drugs. This inhibition may be a factor in the mechanism of action of anti-inflammatory compounds. |
