I read your query and I understand your concern. If one tablet isn t doing it for you then you can up the dose already, its effect should be already visible. However I must confess switching from xanax to clonazepam doesn t make that much sense to me, they belong to the same class, benzodiazepines, have similar efficacy and side effects and with long term use both develop tolerance (don t achieve initial effect for the same dose). In someone who is predicted to need long term treatment for anxiety antidepressants are more indicated. Their effect needs some weeks (so in those first weeks can be given together with a benzodiazepine) but is more stable in time, talk with your doctor about their use. I hope to have been of help.