Will a whole 0.25 Xanax (alprazolam) cause me to feel spaced out or cause derealization? This is why I'm nervous to take whole one but half don't relax me much.

Xanax (alprazolam) Is an anxiolytic frequently prescribed for panic attacks with many side effects. Your doctor has prescribed this medication because he/she has judged that the benefit to you is greater than the risk of side effects. It is not true in your case. Rec.: see your doctor for medication adjustment/change or referral to psychiatrist.