Recently left my company due to being overworked, being underpaid, and lack of drafting support from new hires that were promised but never delivered. If it's from time to time I didn't worry about it. If it has become a problem, then look into the hand-off procedures from jobs being awarded, to being handed off to the drafters, and see how much time they are actually taking. One thing I did, was stand my ground. I can only design and draft so fast - beyond my skill it just simply overflows into more time - which I informed I will NOT do, due to some recent complications in me being overworked for 3 months straight with zero compensation (I was salary and already worked 45 hours a week normally).
If it still is a problem, try logging everything and then presenting it to upper management. Hope this helps some.