2. • Opioids are potent respiratory depressants,
and overdose is a leading cause of death
among people who use them
• Worldwide, an estimated 69 000 people die
from opioid overdose each year
• Among people who inject drugs, opioid
overdose is the second most common cause of
mortality after HIV/AIDS
3. Opioid overdose
• Opioids depress the respiratory drive and
overdose is characterised by apnoea, myosis
and stupor
• A severely reduced respiration rate results in
hypoxaemia, leading to cerebral hypoxia and
impaired consciousness.
• Cardiac arrest is a late complication of opioid
overdose and secondary to respiratory arrest
and hypoventilation.
4. • Prolonged cerebral hypoxia is the mechanism for
brain injury and death in opioid overdose,
resulting from apnoea or cardiac dysrhythmias
and cardiac arrest.
• Opioids act at μ, κ and δ-opioid receptors, which
are widely distributed throughout the body.
Endogenous opioids act tonically on brain-stem-
located opioid receptors to modulate respiration
in response to hypoxia and hypercapnea
5. • These centres are in turn modulated by
connections to other structures in the central
nervous system (CNS) including the motor
cortex, the cerebellum and limbic centres.
• Administered opioids depress all components
of the respiratory drive (the rate and depth of
breathing).
6. • An effect most pronounced in individuals with
chronic cardio-pulmonary and renal disease,
whose respiratory responses are diminished.
• In addition to reducing respiratory drive,
opioids reduce upper-airway tone and chest-
wall rigidity.
7. Preventing opioid overdose
• monitoring opioid prescribing practices;
• curbing innapropriate opioid prescribing;
• curbing inappropriate over-the-counter sales
of opioids;
• increasing the rate of treatment of opioid
dependence, including for those dependent
on prescription opioids
8. Management of opioid overdose
• Death in opioid-overdose can be averted by
emergency basic life support resuscitation
and/or the timely administration of an opioid
antagonist such as naloxone
• Naloxone (n-allylnoroxymorphone) has been
used in opioid overdose management for over
40 years, with minimal adverse effects beyond
the induction of opioid withdrawal symptoms
9. • It is a semisynthetic competitive opioid
antagonist with a high affinity for the μ opioid
receptor.
• It rapidly displaces most other opioids from
opioid receptors, and if given soon enough will
reverse all clinical signs of opioid overdose
• It can be administered by a variety of routes
including intravenously (IV), intramuscularly
(IM), subcutaneously (SC) and intranasally
(IN).
10. • It carries no potential for abuse, although
high doses may lead to the development of
opioid withdrawal symptoms such as
vomiting, muscle cramps and agitation.
