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Well, from your description ,your diagnosis is Generalized personality disorder ( GAD ) with Panicity ( PANIC DISORDER) . You see both GAD and Panic disorder are types of anxiety
disorders , so there is no need to give separate medications for them , as the anti depressants and anti anxiety drugs which work well for GAD , will also work well enough for Panic disorder.
So, now coming to your question , both Pristiq ( desvenlafaxine ) which is a modified version of venlafaxine ( effexor) as well as Prozac ( Fluoxetine) , will work well for your condition of GAD and Panicity , but here you have to choose one out of these two , as there is no need for the other when one is being used , plus using together may put you at the risk of developing cross tolerance , making both drugs less effective , and also causing severe side effects such as Serotonin syndrome which occur when SSRI s ( that is fluoxetine) and SNRI s ( pristiq ) are used together.
So, here is the treatment regime that you should get started on after discussing it with your doctor.
1) Start on Prozac ( Fluoxetine ) , as you have already used effexor for 2 years , so probably pristiq being a modified version of effexor , may not prove as effective as prozac .
to prozac , Buspar ( buspirone ) , which is an anti anxiety drug , to be taken two times a day , let your doctor decide on the dose , usual doses are 5 mg and 10 mg , but better to be started on low dose.
So, i suggess you discuss these two mentioned medications with your doctor and get started on them , and i am quite sure you will benefit from this regime.
I wish you best of health .
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