Trauma-what kind of clinical settings do you work? Good post. You more or less just beat me yet again today.
Devildog(marine?) I'll let you answer Trauma's post. If you really do have a true allergy or even you just can't handle the side effects/adverse reactions from pain killers then I would suggest trying the OTC NSAIDS i.e. tylenol and motrin. If they don't help enough each by themselves then take them alternating. You can't take too much of each in a day, but if you dose tylenol then take motrin at the next dose time, then tylenol the next. You can keep a constant flow of NSAIDS instead of having the peaks and troughs. Also, maybe look into some homeopathic remedies like pressure points, massages etc. Lie down in a dark room, quiet, flat with a soft pillow, and a cold/cool cloth over your eye/head for headaches/migraines along with tylenol/motrin can help tremendously. I am of course assuming you are talking about more than minor aches since you refer to prescribed painkillers.
If you have real serious pain, serious injuries go see a doctor.