I had 2 alkaseltzer x-strength + 2 liquid advil (ibuprofen) right after (i've no medical conditions). i didn't think of this until now, but what are the dangers??

Aspirin & ibuprofen: not a great idea (bleeding risk, stomach irritation etc) - but if one time, unlikely to cause any harm. just don't make it a common thing.

Stomach irritation: Although it's not advisable to take these medications simultaneously, I wouldn't expect a dangerous effect but there could be a mild stomach irritation if there was an empty stomach when you ingested them. The medications would wear off after approximately 6 hours.

Not encouraged, but: ...fortunately the Alka Seltzer has aspirin, acetaminophen and caffeine. The Advil (/ibuprofen) will behave similarly to the aspirin as both are in the NSAID family. Isolated mistake will not cause problems, but not recommended for regular use.

Dr Fowler and another doctor agreed