15 NSAIDs Flashcards
What are prostanoids and what do they do?
Prostanoids= a type of eicosanoid
Produced locally on demand
Examples= prostglandins, prostacyclin, thromboxanes
In general terms, how do NSAIDs work?
NSAIDs- inhibit down stream products of arachidonic acid by inhibiting COX (compete with arachidonic acid for hydrophobic site of COX)
Work as:
- Antipyretics
- Analgesics
- Anti-inflammatory
How is arachidonic acid synthesised from linoleic acid?
Linoleic acid obtained from diet- vegetable oils
Linoleic acid= converted hepatically to arachidonic acid (found throughout body- in particualr in muscle, brain and liver)
Differentiate between the 2 functional isoforms of cyclooxygenase enzymes.
(don’t need to learn table- not an exhaustive list)
Through what types of receptor do prostanoids act?
GPCRs
Give examples of 5 prostanoids.
Give 2 examples of substances which can enhance the action of prostanoids.
Local autocoids eg:
- Bradykinin
- Histamine
What effects do thromboxane (TXA2) and prostacyclin (PGI2) have on vasculature?
Thromboxane= vasoconstrictor
Prostacyclin= vasodilator
NSAIDs have 3 major actions: analgesic, anti-inflammatory and anti-pyretic. How do they work as analgesics?
NSAIDs have 3 major actions: analgesic, anti-inflammatory and anti-pyretic. How do they work as anti-inflammatories?
Symptomatic relief by COX inhibition- little/no effect on underlying condition
NSAIDs have 3 major actions: analgesic, anti-inflammatory and anti-pyretic. How do they work as anti-pyretics?
Name 6 NSAIDs and put them in order of increasing COX-2 or increasing COX-1 selectivity.
- Aspirin
- Ibruprofen
- Naproxen
- Diclofenac
- Celecoxib
- Etoricoxib
Differentiate between naproxen and naloxone
Naproxen= NSAID
Naloxone= opioid receptor antagonist (used for overdose)
What is the most common ADR for NSAIDs? Explain why.
GI upset
- Dyspepsia
- Nausea
- Peptic ulceration
- Bleeding
- Perforation
Why?
COX enzymes inhibited, prostaglandin synthesis affected
Less mucus and bicarbonate secretion
More acid secretion
Less mucosal blood flow
Enhanced cytotoxcity and hypoxia
What are the cautions for prescribing NSAIDs?
GI
- Can cause exacerbation of IBD
- Loacl irritation and bleeding from rectal admin
- Caution:
- Elderly
- Prolonged use
- PPIs
- Anticoagulants
- Smoking
- Alcohol
- History of peptic ulceration
- Helicobacter pylori