Strong opioids

Question 1

Mechanism of action?

Answer 1

Opioids (naturally-occurring+synthetic analogues), their effects are produced via activating mu receptors in CNS, activation of these G protein coupled receptors reduces neuronal excitability &pain transmission. In the medulla, they blunt response to hypoxia &hypercapnea. Consequently (by reducing pain, breathlessness &anxiety), they reduce sympathetic NS acitvity, reducing, by that, myocardial work &oxygen demand in IDM &OAP.

Question 2

Indications?

Answer 2

• pain relief, when paracetamol, NSAIDs &weak opioids failed to do so.
• acute severe pain for rapid relief (post-op pain, pain asso /IDM)
• OAP, to improve breathlessness &anxiety, in asso with furosemide, oxygen &nitrates.

Question 3

How are they taken?

Answer 3

For chronic pain, immediate-release tablets are given (ex, 4hrly) when the optimum dose is found, switch to modified-release tablets

Question 4

Important AE?

Answer 4

respiratory depression, neurological depression. N&V (stimulation of CTZ). Pupillary constriction (stimulation of the Edingar Westphal nucleus). Constipation (due to activating mu rcpt that increases smooth muscle tone &reduces motility). Itching, urticaria, vasodilation &sweating (due to histamine release induction). Continued use leads to tolerance &dependence.

Question 5

Important interactions?

Answer 5

Other sedating drugs (antipsychotics, BZDs, TADs), patients with respiratory failure.

Question 6

Name strong opioids?

Answer 6

Morphine, Oxycodone, Buprenorphine, Fentanyl, Hydromorphonen, Nalbuphine, Pethidine, Tapentadol. Sulfentanil.

Question 7

Les trois opioides les plus puissants?

Answer 7

Fentanyl : 100× plus puissant que le morphine
Buprenorphine : 30× plus puissant
Nalbuphine : 2×

Question 8

Combinaison cause la plus fréquente des décès par surdose?

Answer 8

Opiacé + BDZ anti-anxiété.

Question 9

Antidote?

Answer 9

Naloxone.