RESUMO
Pingandan was a secret prescription for treatment of stomach upset, nausea and vomiting for emperors in the Qing Dynasty of China. This study was to compare the effects of Pingandan with those of scopolamine and dramamine on motion sickness (MS) and nystagmus. Fourteen cats were tested in a parallel swing (0.22 Hz, 3.9 m/S2) for 20 min, and then in a rotating chair (10 degrees/S2, 20 rpm) for 1-2 min. The effects of scopolamine 1 mg, dramamine 25 mg and three doses of Pingandan 50x, 30x, 10x of 0.45 g/kg were observed and compared to placebos. These drugs or placebos were administered to each cat 30-60 min prior to the tests. The post-rotary nystagmus and MS symptoms were recorded. The Suri's scale for MS severity, Latin square and double blind techniques were used. The interval between any two tests was 2-5 days. It was found that Pingandan 50x and scopolamine 1 mg were more effective than placebos in reducing MS symptoms (P less than 0.01) and suppressing slow phase velocity of nystagmus (P less than 0.05), while Pingandan 30x significantly reduced MS symptoms only (P less than 0.01). Pingandan 10x and dramamine 25 mg had no anti-MS effect. Chinese medicine Pingandan is an effective anti-MS drug.