A client with panic disorder is taking alprazolam (Xanax) 1 mg PO three times daily. The nurse understands that this medication is effective in blocking the symptoms of panic because of its specific...

A client with panic disorder is taking alprazolam (Xanax) 1 mg PO three times daily. The nurse understands that this medication is effective in blocking the symptoms of panic because of its specific action on which of the following neurotransmitters?

1. Gamma-aminobutyrate.

2. Serotonin.