Dynamics of pain threshold changes (primary protective reaction in “hot plate” test in mice) after intraperitoneal introduction of drotaverine (6 mg/kg), papaverine hydrochloride (9 mg/kg), bendazole (2 mg/kg) and platyphylline hydrotartrate (0,6 mg/kg) was researched. Papaverine hydrochloride was established to increase analgetic effect by 55 % with the peak at the 60th minute. The maximum pain relief of drotaverine was observed also in an hour and was 48,7 %. The most expressed antinociceptive effect of bendazole and platyphylline hydrotartrate was showed up at the 90th — 49,6 % and 60th minute — 54,5 % accordingly.