Morphine Dosing & Tolerance
We’re are going to continue on the theme of opioids because this is Narcweek, it’s what we do. I do have more info/stories on Fentanyl, but I think they’re going to have to wait for another time…I wouldn’t want to wear you guys out on one drug when there are so many to cover. I want to continue on opioids, and what I want to demonstrate is that opioids really have no maximum as far as dosing goes. So what does this mean, and how is it relevant? Individuals can develop tolerance to opioids which means that over time, they may need increasing doses to receive the same effects. Because of this, you may see patients from time to time on extremely high doses that would certainly be lethal to opiate naïve individuals (i.e. those who aren’t on regular opioids). I had an example of this a while ago where a patient on hospice who was on 300mg of MS Contin three times per day, with a prn dose immediate release dose of 120 mg! That’s the highest dose of opioid I’d seen in quite some time. If you had to prescribe, administer, review or dispense this dose, it should scare the crap out of you. I have seen wrong patient med errors happen, and this is a case where it would likely have a chance to be fatal if given to the wrong individual. With usual starting doses in the ballpark of 5-15 mg orally, you can really see how this tolerance effect is demonstrated.