In the name of God
Opioids
Dr.Ali Ostadi.MD
History and Epidemiology
Papaver somniferum
Opioids are available in various
formulations that allow administration
by virtually any route: epidural,
inhalational, intranasal, intrathecal,
oral, parenteral (ie, subcutaneously
[SC]/IV/IM), rectal, transdermal, and
transmucosal
DEFINITIONS
• Opium
– Fluid obtained from
the poppy plant
• Opiate
a substance derived –
from opium
• Opioid
– substance with
morphine-like actions,
but not derived
directly from the
Papaver Somniferum poppy plant
“Poppy Plant”
Opiate or opioid tend to be used interchangeably.
Pharmacology
Opioid-Receptor Subtypes
Mu Receptor
Kappa Receptor
Delta Receptor
Nociceptin/Orphanin
Sigma Receptor
Other Receptors (Epsilon „Zeta)
µ1
Supraspinal analgesia
Peripheral analgesia
Sedation
Euphoria
Prolactin release
µ2
• Spinal analgesia
Respiratory depression
Physical dependence
Gastrointestinal dysmotility
Pruritus
Bradycardia
Growth hormone release
K1
• Spinal analgesia
Miosis
Diuresis
K2
• Psychotomimesis
Dysphoria
K3
• Supraspinal analgesia
Delta
• Spinal and supraspinal analgesia
Modulation of µ-receptor function
Inhibit release of dopamine
Nociceptin/orphanin
• Anxiolysis
Analgesia
Clinical Manifestations
• Cardiovascular Peripheral vasodilation
• Orthostatic hypotension
• Bradycardia
• Dermatologic Flushing (histamine)
• Pruritus
• Endocrinologic Reduced ADH release
Reduced gonadotrophin release
• Gastrointestinal Reduced motility
Reduced gastric acid secretion
Increased biliary tract pressure
Increased anal sphincter tone
• Neurologic Sedation, coma
Analgesia Euphoria
Seizures (meperidine, propoxyphene)
Antitussive
• Ophthalmic Miosis
• Pulmonary Respiratory depression
• Bronchospasm (histamine)
• Acute lung injury
Toxic Effects
• Mental status depression,
• hypoventilation,
• miosis,
• and reduced bowel motility are the classic
elements
Respiratory Depression
Acute Lung Injury
Cardiovascular
Miosis
Seizures
Movement Disorders
Gastrointestinal Effects
• Diagnostic Testing
• Laboratory Considerations
Management
• Antidote Administration
• the lowest practical naloxone dose
should be administered initially
If a naloxone bolus (start with 0.05 mg IV
and titrate)
Body Packers
Agonist-Antagonists
Meperidine
• Normeperidine causes excitatory
• neurotoxicity, which manifests as delirium,
tremor, myoclonus, or seizures