Table 3.

Mechanisms underlying DDIs involving opioid analgesics used for pain treatment in patients with cancer

Mechanisms underlying DDIs of opioid analgesics
Pharmacokinetic DDIs
1) Inhibition or induction of opioid metabolism through CYP450 or other metabolizing enzymes19,20,24,27–33,36–41
2) Decreased renal elimination of an opioid22,23
3) Inhibition of the metabolism of other drugs exerted by an opioid11,12
Pharmacodynamic DDIs
1) Potentiation of analgesic efficacy and toxicity through opioid and nonopioid mechanisms18,19
2) Inhibition or reversal of the effect of an opioid by antagonism at opioid receptors, or by other mechanisms15–17
3) Modification of cholinergic, adrenergic, dopaminergic, and serotoninergic activity in the CNS10,13,14,25,26,34,35
Others (including DDIs with unknown mechanism)21

Abbreviations: CNS, central nervous system; DDI, drug–drug interactions.