you need to be worming against tape worm at this time of year. As your results came back clear, I would recommend using equitape to knock the tap worms only on the head. Remeber worm counts don't count for tape worm...
Slightly, but Pramox is active for 13 weeks so will be fine. It is normal to worm for Tape only once or twice a year anyway. I only worm for Tape once as only my horse on grazing and I poo pick daily.
I thought it was the moxidectin (ivermectin family) in pramox and equest that works for 13 weeks, didnt think that this applied to the praziquantel for tape, but may be wrong. why not check with vet?
No need to worm at present.
You can treat tapes at six monthly intervals if you need to, or only once a year in good clean conditions, horses kept in own place, where there has never been a tape problem