[Chromosome studies on human fibroblast cultures following exposure to cyproheptadin]

Cyproheptadin was tested on chromosomes in fibroblast cultures of children for its possible mutagenic efficacy. Neither 24-hour exposure to Cyproheptadin at concentrations of 8-16 mg/l medium nor a chronic exposure for 8-11 weeks at a concentration of 8 mg/l caused any discernable chromosomal mutations. At concentrations between 8-16 mg/l reversible cytomorphological and cytochemical changes occured; 32 mg/l suppressed cell division and higher concentrations (64-128 mg/l) brought about irreversible changes leading to cell death. These reactions were rather in vitro cytotoxic effects of unspecific nature.