Case of the Month #28: Opioid-induced hyperalgesia by Dr Nofil Mulla

Opioid-induced hyperalgesia

Opioid tolerance

Opioid withdrawal

Opioid use disorder

Mechanism

Drug-induced pain sensitization within the CNS (central sensitization)

Decreased drug efficacy
Desensitization of μ-receptor to opioids

Absence of μ-receptor stimulation
Increased NE levels result in systemic symptoms

Uncontrolled use of opioids despite adverse outcomes
Possible desensitization to opioids

Opioid escalation

Pain not overcome with opioid dose escalation

Pain overcome with opioid dose escalation

Symptomatic improvement with opioid escalation

Variable response to dose escalation

Other symptoms

Pain worse with dose escalation

Tolerance to many opioid side effects but not central apnea or constipation

Symptoms include muscle spasm, abdominal cramp, anxiety, palpitations, and hot flashes

Symptoms of tolerance and withdrawal, depending on the presence or lack of opioid use