The effect of certain barbiturates on the porphyrin metabolism of rabbits

Abstract

Barbiturates were suspected of adversely affecting the clinical course of acute porphyria. To assess this objectively, the effect of 9 barbiturates on the porphyrin metabolism of rabbits was observed. These barbiturates may be classified into 4 groups: (a) Diallylbarbituric acid, which caused a considerable rise of urinary coproporphyrin III in each of 8 experimental rabbits and in 3 of these the excretion also of uroporphyrin III and porpho-bilmogen. (b) Allylisopropylbarbituric acid and sodium allyl (1-methylbutyl) barbiturate, which caused a moderate rise of urinary coproporphyrin HI. (c) Sodium diethylbarbiturate, sodium ethyl-(1-methylbutyl) barbiturate and sodium ethylphenyl-barbiturate, which caused only a slight coproporphyrin increase in the urine. (d) Sodium ethyl(l-methylbutyl) thiobarbiturate, sodium isoamylethylbarbiturate and sodium butylethylbarbiturate, which did not alter significantly the urinary coproporphyrin excretion.