That's odd... That you're restricting pain meds.
Amputees (even single digit amputees) are usually in extreme pain, the body doesn't heal very well (as in slower and less deftly) when in pain, and ever surgeon / recovery doc I've ever known says to NEVER restrict pain meds post-op. If you don't stay on top of the pain, it gets way ahead of you, and really negatively impacts recovery.
In Children's hospitals, infants occasionally need to be weaned off pain meds after being on them for months and months... But Ive never heard of them being restricted like that, especially on such a short term basis.
((UMMM.... So there's "PRN" in English that translates to "as needed", and there's "scheduled"... Which means every x hours (2,4,6,etc) around the clock regardless as to pain level. I'm wondering if you misunderstood, and you're supposed to be giving the meds PRN? Which means at FIRST sign. NOT letting things get out of hand, then taking the edge off a bit. I would check back and make sure. Also, know that most post op meds are supposed to be refilled. They don't give you the entire recovery period up front in most cases. So if you're looking at the dropper & trying to make that stretch 6 weeks... Don't. ))