You might notice a few mild side effects like dry mouth, drowsiness, and recurrent dreams while taking Buspar. These are reported very commonly and you can continue the medication if you happen to experience these symptoms. However, in rare cases, you might experience one or more of the following serious side effects like irregular heartbeat, hives, difficulty in breathing, swollen face, involuntary movement of your limbs, and depression. In such cases, stop the medication immediately and get medical attention.