Serum levels of 5-chloro-7-iodo-8-quinolinol and its toxicity in various animals.

Abstract

During long-term chronic intoxication studies, serum levels were measured in dogs and monkeys orally given 5-chloro-7-iodo-8-quinolinol (Clioquinol or Chinoform) (CF) with fixed or increasing doses. Typical neurotoxic symptoms and histological changes developed both in the adult and infant dogs, while the symptoms were poorly required in the monkeys which also showed neurohistological changes. The minimum serum levels of CF at the beginning of intoxication were 6.0-22.6 μg/ml in the adult dogs administered with 100 mg/kg/day, 0.1-1.9 μg/ml in the infant dogs with 740 mg/kg/day, and 2.6-8.8 μg/ml in the monkeys with 1100 mg/kg/day. The single dose experiments were also carried out in mice, rabbits and man. The maximum serum levels of CF reached for the corresponding dosages, (μg/ml)/(mg/kg) were ; 7.2/100 in mice, 0.5-0.7/100 in the rabbits and 2.7-5.8/7-9 in man. The data indicates the relatively easy absorption of CF in man. The relative molar abundance of CF, the glucuronide (CF-G) and the sulfate (CF-S) at maximum serum levels were CF-S&lneCF-G>CF in mice, CF-G>CF-S>CF in rabbits, CF-G>CF-S>CF in monkeys, CF>CF-S>CF-G in dogs and CF>CF-G>CF-S in man.