The urate metabolism of the effects of various antituberculous drugs, especially of
pyrazinamide (PZA), on the urate excretion were investigated. Subjects employed in this
study included both normal and tuberculous (TB) patients. Results may be briefly
summarized as follows:
A. In 14 male subjects, the normal plasma concentration of urate was on the averge
4.3±0.1㎎% while the urinary output of urate was 460±55㎎/day. Similar values were
also obtained in females as well as in TB patients who are treated with streptomycin
(SM), paraaminosalicyliv acid (PAS) or isonicotinic acid hydrazid (INH).
B. The plasma concentration of urate was markedly increased within 24 hours after
the start of PZA administration. This elevation of plasma urate level was maintained as
long as PZA was administered and was associated with the corresponding reduction in
the urinary excretion of urate in absence of any change in both the inulin and PAH
clearances.
C. This anti-uricosuric action of PZA was affected by neither metabolic acidosis nor
alkalosis, which was induced either before or simultaneously with the administration of
PZA.
D. Salicylate (3 gm/day), when administered with PZA, was able to counteract the
appearance of hyperuricemia due to PZA. Moreover salicylate was also able to relieve
patients from the state of hyperuricemia which was brought about by the PZA
treatment.
E. The administration of ACTH (30 units/day) relieved patients from the PZA-induced
hyperuricemia while cortisone acetate (100 ㎎/day) was less effective.
F. The administration of PAH neither altered the urinary excretion of urate nor
prevented the hyperuricemic effect of PZA.
G. The administration of diodrast increased the urinary excretion of urate and in
addition, prevented the hyperuricemic effect of PZA.
H. The possible mode of action of PZA on the urate excretion was discussed.
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