Would Taking Clonazepam And Citalopram Help To Treat Anxiety?

I have been taking citalopram 20mg 1x/day for about 10 days for anxiety. It seems to have little effect. Would taking clonazepam in addition be helpful/advisable? I discovered that I happen to have 10 tablets remaining of a previous prescription of clonazepam 0.5mg which were prescribed at 3x/day.