MOA
Full mu-opioid agonist + NMDA antagonist + serotonin/norepinephrine reuptake inhibitor
Adverse Effects
Pros:
- no renally cleared metabolites, unlike morphine/hydromorphone/oxycodone
- cheap, multiple formulations
- highly effective
- Uses: cancer/bone pain, cancer/neuropathic pain, cancer + SUD
- even effective as add on tx to other opioid regimen
Cons: - long and variable 1/2 life (15-120 hours, lipophilic)
- QTc prolonging (baseline EKG and at 30-40 / 100mg per day)
- complex dose conversions (non-linear pharmacokinetics)
- CYP450 substrate ()