Hi jiveace ,
I have flown a few times on long haul flights from London . I start at Aberdeen which involves a change at London . I take meds 5 times a day so I time them for the flights basically .
I always get a seat next to the toilet for the seven to ten hour flights . I make sure I can walk OK boarding and then leaving the plane at arrivals . .I can afford to delay the meds as long as I can shuffle to the toilet. Then I make sure I take a dose about an hour before landing .
This usually works for me apart from unexpected delays at times . My walking stick usually allows me to be fast tracked in big queues , especially at JFK airport .Then if all else fails I just request wheelchair assistance .
The time delays are easily adjusted to I find by the second day . Enjoy the experience .