I don't think your clients should have to ask you if or why your appear to be high. That's information you need to volunteer and present to the client. Its not an ask thing really.....we will just assume your high on hard drugs.
Definitely wouldn't want to see a lady in a high or lethargic state. Id want the option t declne or just rebook when t wasn't an issue. But truth be told if I was a otental clent and saw that you had a disclaimer for seiizure meds and such.......Id just bypass the date to avoid potential issues.
I would suggest that if you have to take your meds, that you explain the situation to the scheduled clients and reschedule their appointments.
You are under the influence of those drugs while they are in your system and you are not at full mental or physical capacity. You are impaired. There is a reason why people taking seizure medications are often prohibited from driving, operating machinery, or other tasks that take full mental awareness and capacity. It is for their own and others safety. While providing isn't quite the same as operating machinery, there is still the need for mental alertness, proper physical coordination, the ability to be truly aware of what is going on and able to react appropriately.