What opioid pharmacologic agents are available?
Patients with moderate to severe pain or pain related functional impairment not controlled with non-opioids should be considered for opioid therapy. Typically milder and short-acting opioids are attempted prior to the use of stronger opioids. These consist usually of oxycodone, hydrocodone, and tramadol. Tramadol, a weak opioid agonist and monoamine uptake inhibitor, is considered a safer drug with less respiratory and gastrointestinal effects. Care should be taken in patients with a history of seizures, as tramadol lowers the seizure threshold, and with patients on serotonergic drugs due to concern for serotonin syndrome.
Stronger opioids such as morphine, oxymorphone, fentanyl, hydromorphone, and methadone may be indicated in cases where less potent opioids fail to provide adequate pain relief. Many of these stronger opioids come in immediate release and extended release formulations.