Namaste,
Mr. Green offers some excellent advice. Take your medication as prescribed and if you are not anxious and don't feel you need a dosae, then don't take it.
Jikan
If you feel you can manage without some days, then don't take it. I would take the morning and night dosages and consider the one in between. That is the ' if you need ' dosage. If you don't need to take it and feel fine then save it.