Just to alert you, Effexor is a stimulating antidepressant, as it targets norepinephrine as well as serotonin, and so isn't generally used if anxiety is the main problem. It can be helpful if depression is the main problem and anxiety is secondary. So while some anxiety sufferers do well on this drug, many get more anxious on it, so be on the watch for how you feel. As to the number of times a day, some psychiatrists divide the daily dose in two if the drug is having a very sedating effect or a very stimulating effect. It's not an increased dose, it's the normal dose divided into two. Don't know if that's your situation, but my last couple of psychiatrists have prescribed antidepressants in two doses a day for this reason.
The brand name is Effexor. I'm a little surprised your Dr has you taking this twice a day. It's usually taken once a day. Can you say what dose you're on?
If you're asking if it's safe to take Effexor and alprazolam, which is generic for Xanax, yes, you can take the two together. The Effexor should help with your anxiety though so you may want to talk to your Dr about stopping the Xanax. Depending on how you've been on it you may need to taper.