5 - NSAIDs Flashcards
NSAIDS:
- define, fxns,*
- prototype*
- def: nonsteroidal anti-inflammatory drugs
- fxn
- anti-inflammatory
- analgesic (reduce pain)
- anti-pyretic (reduce fever)
- prototype: aspirin
types of inflammation
acute
(immune response)
chronic
mediators of acute inflammation, and the effects on:
vasodilation, vascular perm, chemotaxis, pain
mediatros of CHRONIC inflammation:
& primary effects
where in the process do NSAIDs act? and what do they do?
Prevent arachidonic acid from being converted into PG, thromboxane, prostacyclin
*INHIBIT COX enzymes
where in the body is the NSAID working?
occurs locally at the site of action in the periphery
blocks competitively or non-competitively
what are autacoids, and how are they involved in inflammation?
- biological factors (molecules) which act like local hormones, have a brief duration, and act near their site of synthesis after binding to nerve fiber receptors in the periphery
- function to block pain and inflammation response in the periphery at the site of action (blocking the production of prostaglandins)
which have more adverse side effects and why?
corticosteroids, or NSAIDs?
*corticosteroids, because these act higher up in the process –> more downstream side effects
what are the therapeutic strategies of drugs?
- relief of pain
- slowing or arresting of the tissue damaging process
NSAIDs:
chief clinical use?
- anti-inflammatory agent in tx of musculoskeletal disorders (OA and RA)
- these DO NOT arrest the progression of pathological injury to tissue
- what is the current gold standard to which anti-inflammatory drugs are compared?
- which drug was historically the gold standard (prior to 1960s)
- current gold standard: IBUPROFEN
- previously/historically: aspirin
REVIEW: pharmacokinetics categories?
ADME
- absorption
- distribution
- metabolism
- excretion
Aspirin:
pharmacokinetics (ADME)
- A - rapidly absorbed
- D - found in synovial fluid
- M - metabolized by cytochrome p450
- E - renally excreted
Aspirin:
pharmacodynamics
- IRREVERSIBLY inhibits COX activity
- esp affects platelets
Aspirin:
clinical uses
- analgesia: pain of mild-mod intensity
- antipyretic: little effects on normal Tb
- anti-inflammatory: inflammatory joint conditions
Other uses: prevention of ischemic attacks, unstable angina, thrombotic conditions
Aspirin:
adverse effects
- GI upset; (intolerance) –> upper GI bleeding from erosive gastritis
- Salicylism –> vomiting, tinnitus, dec. hearing, vertigo
- Inc. serum uric acid levels
- Inhibition of platelet function –> blocks (noncompetitively) COX-1 platelets –> change conformation and inactivate platelet (7-11 days) –> won’t function in coagulation response (bad for pt with bleeding disorder)
- Renal BF alterations
- Reye’s syndrome –> causes brain and liver damage
how common are the side effects of Aspirin?
very common!
- Dyspepsia: 15-40%
- Duodenal ulcers: 5-8%
- Gastric ulcers: 15-20%
- GI bleed: more rare, 1-2%
For every $1 spent on NSAIDs –> $0.66 spent on side effects
Can we prevent NSAID- induced adverse events?
Yes! There are some drugs that prevent these:
-
**Proton pump inhibitor:
- reduces chances of damaging gastric mucosa
- cheapest and most effective
- e.g. omeprazole, prilosec, nexium –> dec. liklihood of damaging mucosa
-
Misoprostol: prostoglandin E1 analogue –> protects gastric mucosa from chemical irritation
- PG is important for protection of the GI tract
- replaces the PG that you’re blocking w/ the NSAID
- but can cause diarrhea/ due to contraction of smooth muscles
-
Cox-2 inhibitor
- allows COX 1 to function
these are in which family of drugs?
- diclofenac
- flurbiprofen
- ibuprofen
- indomethacin
- ketoralac
- naproxen
- piroxicam
NSAIDs
diclofenac:
characteristics, use
- developed as a “super-aspirin” to be gentler on the stomach;
- formulations:
- diclofenac alone
- diclofenac + PG analogue
- Tx: dysmenorrhea and gout
- Type of NSAID
flurbiprofen:
characteristics, tx for what
- developed as ocular eye drop
- pre-analgesic prior to eye surgery; or after to tx pain
Ibuprofen:
characteristics, fxn
- **gold standard NSAID; works as antipyretic, anti-inflammatory, analgesic
- thought to be safer than aspirin
- ibuprofen is a COMPETITIVE inhibitor, so it doesn’t have the same effect on bleeding or platelets