You certainly have far more experience in pain management than I, however, I would respectfully disagree that cross tolerance is an issue here. If there is a LACK of cross tolerance...then adjusting the dose is unnecessary In my understanding of the pharmacologic definition of cross tolerance with respect to opioids & their actions on the mu receptors (which is only one of many, many receptors narcotics act on, certainly), cross tolerance is not an issue when changing from one form of ms to another form of ms. It is an issue when changing from one opioid to another, which was not the example given.
At least that has not been a significant influence in my experience when I need to recommend a hospitalized cancer pt be transferred to an appropriate amount of oral morphine so they can return to their home setting. The considerations which come into play, in my limited experience, are ease of dosing, the number of tablets required (since the fillers & binders are nauseating as well as the difficult to swallow as the disease progresses), the cost of the medications & insurance coverage (often insurance limits coverage to #'s of tablets per day - not mg/day - similar to paroxetine or effexor) & the ability of the pt or caregiver to have appropriate breakthrough pain medications to give sl when the pt can no longer swallow (usually a liquid form which can be given with atropine to decrease secretions).
As much as I appreciate your approach to have the pt return to a clinic in a week, for a cancer pt, who appears to be terminal, altho that was not specifically stated, I've never known one to return to a physician setting to adjust the narcotic dose. Normally, the dose is adjusted by hospice nursing with protocol set parameters & orders to inform the physician when the parameters no longer meet the pts needs. This does in no way imply the physician is no longer an integral part of the dosing & titrating of the pts pain requirements for comfort - he/she is, however, not usually by a clinic visit - at least in my area. The balance, in my opinion, in the pt given as an example, is to provide easy, convenient pain relief with the ability to continue interactions with family as long as possible in as comfortable a setting as possible. I've done intravenous ms on pts at home & that is usually a huge burden to the family. I can't imagine an intrathecal pump....
That said....if the pt were a chronic, non-terminal pain patient, yes, I would agree with your recommendations since these folks need to maintain an active life while being treated for their chronic pain, however, that was not the pt mentioned.
There is actually lots of literature out there with regard to narcotic dosing and cancer. NCCN has Practice Guidelines In Oncology for both the pediatric & adult cancer pain patient. Also, most cancer pain pharmacologic measures have been based on principles promoted by WHO (Cancer Pain Relief, WHO, 1986) & have been validated & updated since. There really is no upper limit to analgesia with cancer pain & doses may vary 100-fold, but few patients need doses above the equivalent of 200-300mg/day without the addition of other adjuvant agents.
However, I do recognize the pain clinic which is affiliated with my institution does not consult often on cancer patients. Normally the oncologist handles these patients on their own, so your experience is certainly a different perspective & one in which I would be interested to see in a real patient, which is why I asked. I do thank you for your thoughtful reply and will consider all you've said next time I encounter a similar patient.
