How long will I maintain a useful amount of riba in my blood? I was 100% compliant until 1/30, that is 26 weeks. I suffer migraines and they have progressively become more numerous the last 3 months. I decided I was gonna make 24 wks no matter what. Was intending to do 36 weeks as a RVR. Starting last tues. EVERY time I took my Riba I got a headache. Imitrex is the only thing that works for me but you are not supposed to take more than 4 doses per month. My Neuro. says 8 doses a month are safe. 1 or 2 doses a day is NOT good. Gonna see if I can get in to see him but he can be tough to get to. Soooo, back to my ???. I know riba has a very long 1/2 life. Anyone know how long I can go without it before re-starting it would be a waste? jerry