Mixed Opioid Agonist/Antagonist

These medications are used for the treatment of moderate pain.  These medications tend to cause less dependence than morphine.  Precipitation of withdrawal is a possibility when administering these medications to strong opioid users.  Additionally, pentazocine is rarely used due to its risk of causing nightmares, hallucinations, and dysphoria.

Class Drugs

• Pentazocine

• Nalbuphine

• Butorphanol

Class Mechanism of Action

Opioid Kappa agonist

Partial opioid Delta and Mu agonist/antagonist activity

Class Application

Analgesia

Class Adverse Effects

• See individual drugs

• May precipitate withdrawal in patients currently using strong opioids

Drug Table

Drug Name	Application	Comments	Image
Butorphanol	Analgesia; Nasal formulation used for severe headaches	Adverse Effects; Less likely to induce hallucinations, nightmares, etc. than pentazocine; Increases cardiac preload	"Butane Torch" "Orphan"
Nalbuphine	Analgesia	Adverse Effects; Less likely to induce hallucinations, nightmares, etc. than pentazocine	"Nala (lioness)" "buffoon"
Pentazocine	Analgesia; Effects stem from action at the spinal cord	Adverse Effects; ; -Respiratory depression and decreased GI motility at high doses; -Hypertension; -Hallucinations; -Nightmares; -Tachycardia; -Caution in patients with coronary artery disease; -Increases systemic and pulmonary arterial pressures	"Pen" "Tasmanian Devil"