What are the kinds of medicine that help with motion sickness?

The best is Valium. Valium and other benzodiazepines are preferable to medications like Meclizine (antivert). Medicines like meclizine, bonine and dramamine (dimenhydrinate) are all based on the phenothiazine meds and were discovered as failed antipsychotics. They didn't help psychotic symptoms but made people less dizzy. Valium works great and the side effect profile is preferable so most ear specialists use these medications.
Motion sickness meds. The kinds of medications that are helpful in the managment of motion intolerance are the antihistamines (meclizine, antivert, bonine, dramamine), promethazine, benzodiazepines (valium, lorazepam, clonazepam, alprazolamz) and/or scopolomine. Most common side effect of these medications is drowsiness. Care must be taken with continuous use or high doses of benzodiazepines.