Pain and opioid analgesics

Question 1

What is the MOA of opioids?

Answer 1

• Acts on G-couples protein receptors. Inhibits them by activating potassium ion channels and causing potassium to flow out leading to hyper polarisation. It also inhibits voltage gated calcium channels reducing transmitter release
  
  • Biochemically, it inactivates adenylate cyclase and inhibits cAMP production

Question 2

What are 3 adverse effects of analgesics?

Answer 2

• Causes CNS effects including nausea and vomiting, pupil constriction, constipation, histamine release dry mouth, genitourinary effect and a lowered immune system.

Question 5

What are 3 drug interactions of pain and opioid analgesics?

Answer 5

• Drugs which can lower BP and cause bradycardia
  
  • CNS depressants such as benzodiazepines, pregabalin and gabapentin can increase respiratory depression, profound sedation, coma or death.
  • Oxycodone is metabolised by CYP3A4 which can lead to multiple interactions including clarythromycin, verapamil, carbamazepine, and St John’s wort

Question 6

What are 5 education points for pain and opioid analgesics?

Answer 6

• Take medications when you are feeling pain
  
  • It can make you drowsy and increase alcohol effects
  • Do not drive or operate machinery
  • Stop taking meds if it’s making you feel very drowsy
  • Be careful when standing up, might make you feel dizzy
  • Drink plenty of water and take a laxative regularly to avoid constipation
  • Do not share meds
  • Any unused tablets should be taken to the pharmacy to be disposed.