Predict the Efficacy of three Motion Sickness Models in Human Volunteers Before And After the Administration of Anti-Emetic Drugs

Motion sickness is a common problem which is evoked in a susceptible person, when they are subjected to the movements which have certain characteristics. Although the symptoms of motion sickness may vary somewhat in number and intensity from individual to individual, it can be stated that on an average, they are, drowsiness, facial pallor, cold sweating, salivation, nausea and vomiting. Although good guidelines may be established by animal experiments, this information cannot reliably predict the effects in man due to species differences. Therefore, the important problem is to select a method of study that reduces human variants to a minimum to obtain precise observations and avoid bias and pure psychic response. Three motion sickness models are used to predict more
accurately the anti-emetic effect of two anti-emetic drugs, Metoclopramide & Cinnarizine, from two different pharmacological classes. Three motion sickness models such as, Model A-Head movements in yaw axis rotation and Model B-Chair rotation with head movements and eyes closed and Model C-Chair rotation with head movements and obscured field of vision were used in this study. Twenty healthy human volunteers were divided into two test groups. Tab. Cinnarizine 25 mg was given to one group and Tab. Metoclopramide 10 mg was given to another group. At the end of each test seven motion sickness symptoms such as dizziness, bodily warmth, headache, sweating, stomach awareness, increased salivation, nausea and one sign-pallor were graded as mild, moderate and severe. The response scores were added to give an overall symptom score using 1-10 scale for each test. Motion sickness symptoms were assessed before and 2 hours after administration of drugs. All 3 methods provide an excellent situation for observing the progression of motion sickness symptoms as the subjects become more sick. The waxing and waning of the symptoms was very clear. All these motion sickness provocation tests were technically easy and no special instrument except a rotating chair was required which can be rotated manually. It appeared that there is increased tolerance to almost all symptoms of motion sickness induced by head movements and chair rotation with cinnarizine as compared to metoclopramide.