Precautions
Equianalgesic chart are a useful tool, but the user must take care to correct for all relevant variables such as route of administration, cross tolerance, half-life and the bioavailability of a drug. For example, the narcotic levorphanol is 4–8 times stronger than morphine, but also has a much longer half-life. Simply switching the patient from 40 mg of morphine to 10 mg of levorphanol would be dangerous due to dose accumulation, and hence frequency of administration should also be taken into account.
There are other concerns about equianalgesic charts. Many charts derive their data from studies conducted on opioid-naïve patients. Patients with chronic (rather than acute) pain may respond differently to analgesia. Repeated administration of a medication is also different from single dosing, as many drugs have active metabolites that can build up in the body. Patient variables such as sex, age, and organ function may also influence the effect of the drug on the system. These variables are rarely included in equianalgesic charts.
Read more about this topic: Opioid Comparison
Famous quotes containing the word precautions:
“A multitude of little superfluous precautions engender here a population of deputies and sub-officials, each of whom acquits himself with an air of importance and a rigorous precision, which seemed to say, though everything is done with much silence, “Make way, I am one of the members of the grand machine of state.””
—Marquis De Custine (1790–1857)
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—Benjamin Harrison (1833–1901)
“We must take precautions against being prematurely honed sharp—since at the same time we are being prematurely honed thin.”
—Friedrich Nietzsche (1844–1900)