It might be interesting to have an (optional) 'Morphine Crash' mechanic where after the Morphine effect wears off there is a 'Morphine Crash' effect which makes all injury-debuffs one level stronger than they should be. (because you took morphine to dull the pain rather than actually healing the injuries, which means you were aggravating your injuries by continuing to fight, sprint, etc. at full speed instead of actually healing them)