system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does Dramamine work?
gpt
There are drugs called "antiemetics" which directly suppress the nausea reflex. It happens that these are the same drugs as antihistamines aka allergy medicine, which has the additional effects of reducing allergies and making your really tired. A secondary effect is that motion sickness is (partly) caused by a disparity between what you see and what you feel-- for example feeling like you're sitting still in a car but seeing the world go by at 60mph. This effect is diminished if you're asleep (and you also care less), so the drowsiness can be positive.