Amazon offers the Dramamine Motion Sickness Relief Tablet 12-Pack for $3.39. Add it to your cart via Subscribe & Save to drop the price to $3.22. With free shipping, that's at least a buck less than you'd pay at a local retail store. It prevents nausea, dizziness, and vomiting.
Be sure to cancel your subscription after your order arrives to avoid being billed for subsequent shipments.