I know they say that it takes a few weeks to take affect and has to be taken all the time but I have been taking it on an as needed basis for years. I would tell my doctors that and they looked at me weird cause thats not what the literature says! They Pharma company does a study way back when and decides dosage and they don't usually go back and listen to the patient.
I did take it on a regular basis at one time when my pain was very bad, so my thought is that on some level my nerve endings have a memory for this drug?
Anyway, in answer to your question, I take 100mg as needed and mostly at bed when pain is intolerable, as it can make me dizzy and can make me disoriented..