“…Population pharmacokinetic parameter values are often used to estimate drug dosing regimen designs for individual patients in whom patient-specific parameter values are not available ( 16 , 17 ); however, opioid pharmacokinetic parameter values are scattered about in the vast pharmacology literature. Therefore, we culled a large number of studies using references ( 18 – 21 ), the reference lists therein, the reference lists of the references therein, and literature searches using PubMed.gov and Scholar.Google.com with search terms entered: opioids pharmacokinetics, opioids pharmacodynamics, and the latter terms, substituting the word opioids for each of the 12 individual opioids studied, so as to obtain pharmacokinetic parameter values for the following 12 opioids: ( 1 ) morphine, ( 2 ) tramadol, ( 3 ) codeine, ( 4 ) meperidine, ( 5 ), hydrocodone, ( 6 ) oxycodone immediate-release (IR), ( 7 ) oxycodone controlled-release (CR), ( 8 ) hydromorphone, ( 9 ) oxymorphone, ( 10 ) methadone, ( 11 ) fentanyl, and ( 12 ) buprenorphine.…”