Influence of phenylbutazone on leukocyte chemiluminescence and function

The effect of phenylbutazone on human leukocyte chemiluminescence, phagocytosis and intracellular killing of bacteria has been examined. A marked reduction of chemiluminescence and intracellular killing of bacteria was observed. The effect on phagocytosis was less pronounced. High drug concentrations nearly abolished light emission, and concentrations equivalent to those obtained in plasma during therapy caused a 25--30% reduction. The effect occurred within less than 10 minutes. No permanent effect upon resting cells was observed. Phenylbutazone reduced the effect of sodium azide on leukocyte chemiluminescnece, indicating that the drug might also inhibit myeloperoxidase dependent chemiluminescnece. Whether these impairments of leukocyte function also take place in vivo resulting in enhanced susceptibility to infection remains unknown.