Opioids are mainly used to treat both acute and chronic pain. Several opioids are
metabolized to some extent by CYP2D6 (codeine, tramadol, hydrocodone, oxycodone, and …

Part I of this article discussed the potential functional importance of genetic mutations and
alleles of the human cytochrome P450 2D6 (CYP2D6) gene. The impact of CYP2D6 …

Codeine is bioactivated to morphine, a strong opioid agonist, by the hepatic cytochrome
P450 2D6 (CYP2D6); hence, the efficacy and safety of codeine are governed by CYP2D6 …

Cytochrome P450 enzymes are essential for the metabolism of many medications. Although
this class has more than 50 enzymes, six of them metabolize 90 percent of drugs, with the …

Tramadol, a centrally acting analgesic structurally related to codeine and morphine, consists
of two enantiomers, both of which contribute to analgesic activity via different …

Interindividual variability in drug response is a major clinical problem. Polymedication and
genetic polymorphisms modulating drug-metabolising enzyme activities (cytochromes P450 …

Pharmacogenetics is the study of how interindividual variations in the DNA sequence of
specific genes affect drug response. This article highlights current pharmacogenetic …

Respiratory depression limits the use of opioid analgesia. Although well described clinically,
the specific mechanisms of opioid action on respiratory control centres in the brain have …

Tramadol is a synthetic, centrally acting analgesic agent with 2 distinct, synergistic
mechanisms of action, acting as both a weak opioid agonist and an inhibitor of monoamine …

Codeine is bioactivated to morphine, a strong opioid agonist, by the hepatic cytochrome
P450 2D6 (CYP2D6); hence, the efficacy and safety of codeine as an analgesic are …