Ady, I ran the AW on a good dose of diclofenac to calm down my sciatic back problem. I wouldn't have been able to run it otherwise: as it was, I did a decent time!
I took 100mg the night before and 100mg with breakfast: with the race starting at 11.30 there was plenty of time to have a decent brek and let it all go down.
Diclofenac is harder on the stomach than ibuprofen so I need to take them with food and like most people I can't run within two hours of eating anything substantial, so that sort of dictates when I can take them.