Hi. i was prescribed atarax (hydroxyzine) for anxiety. about an hour after taking it my hr shot to 104bpm. i guess it did the opposite? dont take again correct?

Probably ok: 104 is slightly fast, but not very. Our hearts often normally reach such a rate temporarily during the day. Typically hydroxyzine doesn't cause an increase in heart rate. But it is not a very powerful medicine for anxiety. IF you had anxiety at the time of the 104 heart rate, it just may not have been working very well. Perhaps some reassurance that a temporary hr of 104 is not serious?