Anti Inflammatory Medications Flashcards
What is aspirin more selective to in regards to its anti inflammatory effect
COX1
What makes the drugs go for either the COX1 or COX2
Cox 1 and 2 have slightly different structure, Cox 2 has a set of hydrophobic residues at the active site that can be targeted by these drugs but this is completely absent in Cox1
What is unique about the interaction of aspirin on Cox 1 and 2
It irreversible binds with Cox 1 and covalently modifies the active site by chemically reacting with the serine residues
What are glucocorticoids used for
To reduce inflammation and immunity
What are their side effects (GC)
They cause an increase in glucose level in the blood.
What are NSAIDs used for
To reduce fever, reduce inflammation and treat pain
What do NSAIDs work on
COX
What do GCs work on
They work upstream of NSAIDs, inhibiting PLA2 (phospholipase A2)
What are the effects of mineral corticoids
Antidiuretic, keeps water and Na ions from going into the filtrate in the nephrons
What are the effects of acitaminophen
It reduces fever, headaches and pains. Does not reduce inflammation significantly
What is important to know regarding the dosing effects of these drugs
Drugs that have a shorter half life are quicker to act but they have to be dosed more often whereas drugs with longer half lives dont have to be taken very often but they take a while to kick in
What is the significance of dosing in terms of anti inflammatory effect and analgesic effects
Higher dosing is required for anti inflammatory than analgesic, for ibuprofen double the amount is required for anti inflammatory response as compared to the analgesic response
What is one major side effects of all kinds of NSAIDs
Nephropathy due to lower GFR
What is the interaction of NSAIDs and Aspirin
Both compete for the active site of COX1. However, NSAIDs have a higher affinity for COX1 than aspirin so taking an NSAID with aspirin can reduce the cardioprotective effect of aspirin. It is recommended that aspirin should be taken several hours before NSAID is registered to a patient
Is Acetaminphine an NSAID or GC
Neither
What is the side effect of acetaminophen
Hepatotoxicity
Examples of GC
Cortisol and hydrocortisone
How does GCs inhibit inflammation
- Inhibits COX2 which is required for making NFkappaB
- Upregulates Annexin 1 which blocks PLA2, PLA2 is also needed for inflammation since it makes leukotrines from arachidonic acid metabolism
- It inhibits MAPK Phosphatase 1 which is involved in several pathways
Compare NSAIDs with GCs
NSAIDs:
- Mild inflammation and fever
- Controls pain
- Only provides symptomatic relief to the pain and fever
- Does not have non immunomodulatory effect
GCs:
- Severe inflammatory suppression effect
- Autoimmune diseases
- Transplants
- Serious side effects
Side effects of GCs
- Hyperglycemia
- Behavioral changes, can induce psychosis
- Weight gain and increased apetite
- Na ions and water retention leading to hypertension
- Loss in K
- Pancreatitus and GI bleed
- Left shift of WBCs leading to more bands and segs, (called bandemia)
What are the long term effects of GC
- Cushing’s syndrome - fat redistribution to the trunk or in the center of the body
- Osteoporosis and impaired growth and development in children
- Glucoma and catercts
- HPA axis being messed up that has to do with stress response
- Prone to infections and poor wound healing
- Withdrawl
How do we select GCs
- Consider the tissue that is being targetted
- Kinetics and half life, how fast is it absorbed and how and where is it absorbed in the body
- Mineralcorticoid effects:
Hydrocortisone>prednisone>dexamethosone
There is an inverse relationship between
Mineralcorticoid (antidiuretic effect) effect and glucocorticoid effect.
How are GCs and MCs administered
- Topical
- Oral
- Injections
- IV for fast acting
Dosing considerations for GCs
- Physiologic conc. is low dose
- Diurnal variation: 2/3rds in the morning and 1/3rds in the afternoon to mimic cirdcadian rythm
- High doses for short period of times
- High doses for acute treatment and then switch to low doses
GC drug interactions
- CYP enzyme metabolism, can have drug interactions that are metabolized by the same pathway
- Side effects like hyperglycemia and hypertension can be beneficial or detrimental
- Taken with food to reduce the risk of GI bleeding
- Cytoprotective agents can be given such as proton pumps to reduce the incidence of GI bleeds
What is the selectivity for Celecoxib
COX2