Other opioid agonists

[SH4:p115-116]

Hydromorphone

• 5 times as potent as morphine
• Slightly shorter duration of action
• More sedation, less euphoria than morphine
• Rapid elimination and redistribution
  --> Oral dosing Q4H is necessary
• A nasal transmucosal delivery system is available
  * Due to high water solubility and medium duration of action

Oxymorphone

• Oxymorphone = addition of a hydroxyl group to hydromorphone
• About 10 times as potent as morphine
• Causes more N&V
• Physical dependence risk is high

Hydrocodone

• Used as oral preparation
• For chronic pain
• High abuse potential

Diacetylmorphine (Heroin)

• Synthetic opioid
• Acetylation of morphine
• Rapid penetration of BBB
  --> Then hydrolysed in brain
  --> Into active metabolites monoacetylmorphine and morphine (in brain)

Diacetylmorphine vs morphine

Parenteral heroin has

• More rapid onset
• Lack of nauseating effect
• Greater potential for physical dependency