depends if you can handle the side effects (if u experience any) of taking it all in one go. if no problem, go ahead and take all in one go, once a day as you were prescribed (I recommend in the morning and with food). i split mines since i cant handle the loss of fluids all at once. As for efficacy from 1 dose vs. split dose, it doesn't matter. The duration of spiro in your system is about 2-3 days, maximum effects may not be seen until two weeks.