Hello i took atarax (hydroxyzine) 12.5mg last night once for insomnia. today i feel extreme breath problem and rapid heart rate what should i do please? urgent!

Time: There has been recent warning on cardiovascular issue from atarax (hydroxyzine). I expect that the anticholinergic effect would subside in less than 24 hours. However if this problem is very bothersome, you will need to go to the emergency room if you can't get an appointment with your own doctor. In the meanwhile, avoid any stimulant such as caffeine.