Disposition of pipecurium bromide in rats.

The disposition of 2 beta,16 beta-bis-(4'-dimethyl-1'-piperazino)-3 alpha,17 beta-diacetoxy-5 alpha-androstane dibromide (pipecurium bromide, RGH-1106, Arduan), a new neuromuscular blocking agent, was studied in rats by using labelled substance. Radioactive substance is rapidly taken up by the liver and to a lesser extent by the kidneys. The compound is retained by the liver for a longer period of time, some 6% of the administered 14C-activity can be recovered from the liver 21 days after the i.v. administration of the drug. Only traces of radioactivity could be detected in the brain and less than 0.1% of the dose could be found in the foetus. Binding to rat plasma protein is of about 30%. The compound seems to be eliminated with urine, the excreted amount being 37.55 +/- 11.91% and 45.44 +/- 17.29% during 24 and 48 h, respectively. No radioactivity was detected in the expired air.