47.narcotic analgesics

Question 1

general information of narcotic analgesics-opioids

Answer 1

1.frequent abuse
-iatrogenic (prescribing and administration errors)
-overdoses
-drug addiction
2. are CD drugs (controlled-release drugs release their active igredients slowly)
3. social and criminogenic impact

Question 2

Classification of narcotic analagesics- opioids

Answer 2

1. natural - morphine, opium
2. semisynthetic - heroine, codeine
3. synthetic - fentanyl, tramadol

Question 3

Indications for clinical use of narcotic analgesics-opioids

Answer 3

1. analgesia - trauma, intra and postoperative
2. palliative care in oncology patients and mechanically ventilated patients

Question 4

Features of narcotic analgesics-opioids

Answer 4

can be administered
1. by inhalation (snorted, smoked)
2. orally
3. parenterally

Question 5

toxicokinetics of narcotic analgesics-opioids

Answer 5

1. exert specific/selective affinity to the CNS respiratory drive - via the opiod receptors
2. CNS depressant effects, but also inhibition of the oxidative-reduction processes in the mitochondrial electron chain
3. acute poisoning might occur with therapeutic opioid doses in patients with compromised respiration and marked hypoxia - i.e past medical history of copd
4. undergo enterohepatic circulation
5. 50% of the ingested dose is excreted via the urine

Question 6

toxicodynamics of narcotic analgesics-opioids

Answer 6

1.opioid receptor stimulation with therapeutic and toxic effects

Question 7

clinical manifestation of narcotic analgesics-opioids

Answer 7

1.opiod toxidrome
-classical triad of respiratory depression with bradypnea/apnea, miosis, altered LOC

main syndromes
1.cerebrotoxic with CNS depression
2.cardiovascular
3.respiratory - with progression of the intoxication it could complicate with:
a-respiratory complications : acute pulmonary edeme in younger patients e.g aspiration pneumonia
b-prolonged/deep comatose state
c-rhabdomyolisis resulting in AKI
d-GIT paralysis with ileus

Question 8

diagnose narcotic analgesics-opioids

Answer 8

1.medical history
2.clinical examination
3.toxscreening

Question 9

differential diagnose narcotic analgesics-opioids

Answer 9

1. medical history
2. clinical examination
3. toxscreening

Question 10

differential diagnose of narcotic analgesics-opioids

Answer 10

1.acute poisoning with organophosphates and other cholinomymetics
2.antipsychotics
3.head traums
4.acute brain injury

Question 11

treatment approach of narcotic analgesics-opioids poisoning

Answer 11

1.respiratory resuscitation/support -
a-oxygenation,
b-endotracheal tube insertion,
c-mechanical ventilation
2.CPR
3.GIT decontamination:
a- activated charcoal,
b- laxatives
c- repeat gastric lacages and activated charcoal in regard to enterohepatic circulation
d-forced diurrhesis
4.haemocarboperfussion early after exposure
5.cerebroprotectors

Question 12

antidote in narcotic analgesics-opioids poisoning

Answer 12

1.naloxon - competitive receptor antagonist with short duration of action,
titrate to effect with 100-200mcg increments using 0,4mg/1ml ampules up to 2mg iv in total
followed by a continuous iv infusion 100-200mg/h titrated to effect
-it has almost instantenous effect when administered iv
but short lasting 20-30mins
=risk of rebound intoxication

in drug addicts mind the risk of acute withdrawal within 6-18hrs

==naloxone does NOT suppress respiratory drive

Question 13

opioid receptors

Answer 13

mu1,2
kappa
delta

Question 14

mu1 receptors are responsible for

Answer 14

for supraspinal analgesia and euphoria

Question 15

mu2 receptors are responsible for

Answer 15

spinal‐level analgesia and respiratory depression

Question 16

kappa receptors are responsible for

Answer 16

for spinal analgesia, miosis and diuresis (via ADH inhibition)

Question 17

delta receptors are reponsible for

Answer 17

spinal and supraspinal analgesia and for cough suppression