What country are you in ? (in case there are other options)
A quick search reveals :
Meclizine is an antagonist at H1 receptors. It possesses anticholinergic, central nervous system depressant, and local anesthetic effects. ... Meclizine also is a dopamine antagonist at D1-like and D2-like receptors but does not cause catalepsy in mice, perhaps because of its anticholinergic activity.
Mechanism of action: H1 antagonist
Drug class: Antihistamine
@Quarky00 seems to think it's probably okay :
https://sanctioned-suicide.net/threads/time-sensitive-question.28877/post-524553
So I think it will be okay.....