Is it safe to take 0.5mg once a day two days in a row or am i at risk for withdrawal?

We must know the type of medication, the recommended dose, the disorder for which it was prescribed, the duration you've been taking it & your response to the medication in order to provide any advice here. Your prescribing physician can therefore answer your question best.

Details will be needed for a meaningful answer, in general your prescriber will be best to place recommendations in proper clinical context.