4,4-Diphenyl-N-isopropyl-cyclohexylamine-hydrochloride (pramiverine, Sistalgin) was investigated alone and in combination (1 + 1000) with N-methyl-N-(2,3-dimethyl-5-oxo-1-phenyl-3-pyrazolin-4-yl)-aminomethanesulfonate (metamizole) in various species for acute toxicity after oral and intravenous administration, for local tolerance and subacute toxicity. In addition, long-term trials and reproduction toxicity studies were performed with pramiverine. Pramiverine was only slightly toxic and was well tolerated locally as an ampoule solution also in combination with metamizole. The acute trials of the two compounds in mice and rats like the subacute study in rats showed that the toxicity of metamizole was not increased by pramiverine. Rats tolerated in the long-term trial all pramiverine doses examined (0.5; 5.0; 50.0 mg/kg), while cholinolytic concomitant effects were observed in dogs under higher doses (5.0 and 20.0 mg/kg). Pramiverine did not have a foetotoxic and teratogenic effect in mice, rats and rabbits. In the perinatal and postnatal experiment in rats no effect on foetal development, viability and growth of the offspring as well as the course of labour and lactation ability of the dams was observed.