Ok, so I know that there have never been trials where sof+led was done for 12 weeks and then sof+dac.
I also am aware of the possibility of concurrent use of some drugs cancelling out the effect of either and maybe making the situation worse.
So if you tell me that it is stupid to even think about doing this then I can't disagree.
However, I have read the pharmacokinetics of both led and dac and I can't see a reason why you shouldn't follow led with dac, even though the led will be disappearing with a half life of 47 hrs while the dac is building up. Note especially that I am not talking about concurrent use, I am talking about serial use.
There seem to be 2 issues but neither of them indicate any problem:
led does not use the CYP enzymes to metabolise while dac does, so no conflict there.
led may be coadministered with P-gp and/or BCRP inhibitors. dac is both of those, so no conflict there.
You may be wondering why I would even want to think about this. Well, I don't have a good clinical reason, it is just a matter of logistics, and the price of dac came into it too. But now I am wondering.
So if you know of a valid reason why this is a bad idea I'd like to hear it please - by that I mean over and above just an unsubstantiated opinion that it is a bad idea.