Effexor XR and anxiety increase in first two weeks?

Hi, Rofer!
About 11% of Effexor (venlafaxine) users experience this very common but temporary side effect. In fact, this applies to most, if not all. antidepressant/anxiolytic medications.
"Psychiatric
Very common (10% or more): Insomnia (up to 24%), nervousness (up to 21.3%) ANXIETY (up to 11.2%)"
"Side effects have been reported to be generally mild and transient. They are most common during the first 2 weeks of treatment and decrease in intensity and frequency with continued treatment. They generally do not lead to treatment cessation."
Starting this type of medication can be a little rough as your metabolism adjusts to the drug so try to stay positive and carry on. If your anxiety symptoms are severe let your doctor know... a decrease in dosage my help or an ultra short course of another medication can be prescribed to get you through.