Antipyrine kinetics following tetanus vaccination.

Evidence suggests that stimulation of the immune response may be associated with impairment of hepatic drug metabolism. Antipyrine kinetics has therefore been determined in 12 patients on the fourth day following tetanus vaccination. Under these conditions, antipyrine plasma half-life was found to be 14.8 h. Despite the lack of control over antipyrine kinetics, these preliminary results indicate that tetanus vaccination is likely to impair the antipyrine metabolism.