HO Reuter, [07 Mar 2023 at 18:45:06]: Can anyone explain the pharmacokinetics of water-based perphenazine? Has anyone done trials on half-life? I too have had good results with long term tranquilising effect in many species, maybe more for 3 days or so. I find effects of tranquilisers difficult to judge, as some animals seem very calm without tranquilisers, others hectically stressed in spite of tranquilisers (even under same conditions, crates, etc.) I have often wondered how water-based perphenazine seems to have similar long term effect at 1/4 dose to the oil-based perphenazine (Trilafon) we used to use in the past. Obviously the oil-base reduces absorption rate from injection site, thereby having a more slow release long term effect I presume. But water-based perphenazine gets absorbed quickly with good (almost immediate) short term effect, hence should be prone to overdosage with extrapyramidal symptoms. But then it‘s blood concentration with therapeutic effect must also reduce quicker than oil-based product. The total dosage we use is a 1/4 of oil-based dosage. So I would expect having to repeat dose every day to every other day to have same effect as oil-based. Is it not that the effect is much shorter, but tranquilising effect at first gives animals a chance to be calm and then stay calm, in spite of drug levels then below therapeutic dose?
