@Mooki, I'd have to vote highly unlikely on the ginger causing ulcers. Spicy foods do not cause ulcers, Heliobacter pylori does and so do some NSAIDs like too much aspirin, aleve or ibuoprofen. As to the original quaetion all antiemetics have potential side effects but I think the most likely ones when they are used as an emet might use them would be
Psycological dependence, dries out mouth and can cause constipation. I have heard of extremely rare but serious "extrapyramidal" side effects similar to restless leg syndrome being reported. I think the only realistic problems would be they could mask a serious illness or you could become distressed if you were psychologically dependent on them and for some reason couldn't get them.