Non-Opiod analgesic Flashcards Preview

Year 3 - Pain/MSK Drugs > Non-Opiod analgesic > Flashcards

Flashcards in Non-Opiod analgesic Deck (11):

What is the alternative name for paracetamol?



How does paracetamol work?

COX inhibitor that is highly selective for COX 2


What effects does paracetamol inhibiting COX 1 and COX 2 have?

COX 1: Weakly selective for COX1 meaning it has less side effects than NSAIDS in terms of Ulceration, Renal Failure and Cardiovascular events
COX 2: Inhibition of COX 2 in the CNS causes:
- decrease prostaglandins in the thermoregulatory centre of hypothalamus = antipyretic
- Increase in pain threshold


What affect do NSAIDs have the paracetamol is weaker at?

Anti-inflammatory effects


What are the common indications of paracetamol?

1. Acute and chronic pain
2. Antipyretic: helps fever and symptoms eg. shivering


What are the contra-indications of using paracetamol?

1. Hepatic Insufficiency e.g. excessive alcohol use (Reduce dose)
2. Underweight
3. Malnutrition
4. Severe hepatic impairment


Why should you reduce the dose of paracetamol in people with hepatic insufficiency e.g. excessive alcohol use?

These people have an increase in NAPQI which causes hepatoceullar necrosis


Why should paracetamol be avoided in those underweight, malnutrition and have hepatic impairment/

They have reduced glutathione stores therefore can not conjugate NAPQI leading to hepatocullar necrosis


What are the common interactions with paracetamol

CYP450 inducers increase the rate of NAPQI production
Warfarin: paracetamol can increase the INR


What are the side effects of paracetamol

Usually only with overdose:
- Liver failure
- Hepatoceullar necrosis due to NAPQI build up during overdose


What do you give to treat a paracetamol overdose?

- IV infusion acetylcysteine or glutathione