I see no reason not to.
In all of my years, I have never met anyone who has had an adverse effect from listening to any of the work I have done. Either through my own company or with the Monroe Institute / Monroe Products. This is probably because the methods have been so well researched. If you are on anti anxiety meds and are unsure, you probably want to consult your physician.
As I said earlier, in the right hands, binaural beats can be effective in invoking relaxation, but I am not so sure it is because they manipulate brainwaves into specific patterns. TTM recordings are more than just binaural beats anyway. They are skillfully crafted meditation recordings which contain narration, binaural beats, music and many other sounds to enhance the ones natural ability to move into an altered state of consciousness, and trip the relaxation response. If relaxation and meditation is not recommended for treatment of anxiety by your physician, then don’t use these recordings.