Re: Latest on pergolide dosing?
Eleanor Kellon, VMD
Dr. Kellon, if you have more information (which I am willing to bet you have), please jump in!
I think you have pretty much covered it! Could add just to elaborate a bit that unlike in people pergolide peaks rapidly (half hour) with a very short half life (6 hours) in horses. This means that if you dose twice a day there is little chance the effects of those two doses are additive. Therefore, changing from say 2 mg once a day to 1 mg twice a day is decreasing your peak effect to a 1 mg dose. The experience of members bears this out.
This information would seem like a good argument for dosing twice a day instead of once a day since blood levels may be subtherapeutic for most of the 24 hour period. This may well be the case but it hasn't been studied. We don't know what happens to ACTH levels over that 24 hour period or if adding a second dose (not splitting the original dose) helps with control.
Also important to remember the variation in blood levels could (we don't know yet) be important in interpreting your ACTH test results. If blood is drawn 2 hours after a dose the result may be very different than a sample from 12 or 23 hours after a dose.
Eleanor in PA