What's your opinion on treating carsickness?

Prevention can help. If motion sickness is a frequent problem, then it is reasonable to try to prevent onset of symptoms. Over the counter antihistamines taken 30 min prior to travel can help. Transdermal scopolamine applied 4 hours before travel can also help. Once symptoms start then little can be done.
Hyoscyamine sl. I have several patients with severe motion sickness, and all responded well to sublingual hyoscyamine, 0.125 mg tabs. It works even after symptoms start. It has the same action as scopolamine, but remarkably less costly than a patch, which in my view is unnecessary. If one dose doesn't work, another may be taken. My repeat in 2 hours.
Carsickness. Here is a great list of things you can do to prevent or treat carsickness: http://www. Mayoclinic. Com/health/first-aid-motion-sickness/hq01099.