A survey of the leterature on
bismuth toxicity in man in relation to blood level data, has revealed the necessity of distinguishing between
lipid soluble and water soluble organic complexes of
bismuth on the one hand and the simple inorganic
salts of
bismuth on the other hand. A characteristic feature of the former, illustrated by the water soluble
bismuth complex triglycollamate, is the high
bismuth levels (due to absorption of the complex as such) and the nephrotoxic properties of the compound in man.
Bismuth absorption after administration of the simple inorganic
salts of
bismuth is postulated to occur in the form of ionic
bismuth as such, low
bismuth levels being characteristic features of such compounds.
Bismuth blood and urine levels obtained from patients after administration of a new anti-
ulcer drug (
Bicitropeptide) in a well controlled clinical trial are discussed and suggest that that this
bismuth containing
drug behaves pharmacologically in a manner similar to the inorganic
bismuth salts in man, low
bismuth blood levels and the absence of toxic side effects being conspicuous features of the
drug. Based on these considerations, it is proposed that the pharmacologically active
bismuth compounds be divided into four different groups depending on structure, stability and solubility. The question as to what constitutes a "toxic
bismuth blood level" can only be discussed in relation to the new proposed sub-division of
bismuth compounds and is only meaningful if the term is defined to relate only to ionic
bismuth (presumably bound to a large extent to
blood proteins). Based on information gleaned from the literature and blood level values reported in the clinical trial referred to, it is suggested that
bismuth blood level values below 50 micrograms/ml are highly unlikely to be associated with meaningful toxicity in man. Finally, attention is drawn to the reversibility of
bismuth toxicity in man as reported by many authors irrespective of the type of
bismuth compound concerned.