Osteoarthritis (exam 1) Flashcards
cardinal features of osteoarthritis
progressive cartilage loss
subchrondral thickening
marginal osteophytes
what type of disease is OA
degenerative joint disease
osteoarthritic is characterized by
degeneration of cartilage that cushions the ends of bones
treatment for osteoarthritis
exercise
pain medication
is there a drug that can reverse OA?
no
initial drug of choice for OA
acetaminophen
what types of medication can be used to treat OA?
acetaminophen
NSAIDs
capsaicin
tramadol
glucocorticoids
opioids
when does OA begin and how long does it develop compared to RA?
RA: 25-50 yrs; weeks-months
OA: 40 yrs; years
are osteophytes present in RA and OA?
ONLY osteoarthritis
is RF present in RA and OA?
ONLY rheumatoid arthritis
major sign of RA and OA
RA: inflammation
OA: pain
how long does morning stiffness last in RA and OA?
RA: over an hour
OA: under 20 minutes
are fatigue, weight loss and anemia present in RA and OA?
ONLY rheumatoid arthritis
rheumatoid arthritis is a _____________ response while osteoarthritis is a _______________
autoimmune
loss of cartilage matrix
eicosanoids
prostaglandins, thromboxanes, leukotrienes
short lives, extremely potent
formed in almost every tissue of the body
COX1 pathway is ___________ and COX2 pathway is ___________
constitutive (expressed at all times)
inducible (expressed by inflammatory stimuli)
which COX pathway is NSAID sensitive?
glucocorticoid sensitive?
both COX1 and COX2
only COX2
types of prostaglandins in COX-1 pathway
stomach - PGE2
Kidneys - PGE2, PGI2
platelets - TxA2
vascular endothelium - PGI2
COX-1 pathway activation leads to ___________ while COX-2 pathway activation leads to _______________
physiological homeostasis
inflammation
NSAIDs MOA
inhibit the product of eicosanoids by inhibiting the activity of cyclooxygenases
NSAIDs are what type of antagonist?
noncompetitive
NSAIDs posses what type of effects?
anti-inflammatory
analgesic
antipyretic
aspirin MOA
irreversibly acetylates COX1 and COX2
how are NSAIDs antipyretic?
PGE2 crosses BBB to increase body temperature
when this is decreased, body temp lowers
chief metabolic products of aspirin
salicyluric acid (glycine conjugate)
phenolic glucuronide
acyl glucuronide
how is aspirin exerted in the urine?
75% - free salicyluric acid
10% - salicylic acid
10% - salicylic phenolic
5% - acyl glucuronide
aspirin is contraindicated in
vitamin K deficiency and hemophilia
ADRs of aspirin
increase gut irritation
gastric distress
N/V
prolonged bleeding time
nephropathy
where is aspirin metabolized?
hepatic ER and mitochondria
Pharmacokinetics of acetaminophen
extensive 1st pass metabolism in luminal cells of intestine
conjugated in liver to form inactive glucuronidated/sulfated metabolites
part of acetaminophen is hydroxylated to from
N-acetyl-p-benzoiminoquinoneimine (NAPQI)
NAPQI
highly reactive
potentially dangerous metabolite that reacts with sulfhydryl groups
acetaminophen converts into _________________ which can be therapeutic or toxic doses
toxic intermediate
adverse effects of acetaminophen
acute overdoses - fatal liver damage (from NAPQI)
renal tubular damage
are there adverse effects at normal doses of acetaminophen?
rarely
antidote for acetaminophen
how it works?
n-acetylcysteine
contains sulfhydryl groups which interact with NAPQI and detoxify it
MEOS compromises
CYP4502E1 (major)
1A2
3A4
why acetaminophen intake can be toxic after alcohol consumption?
increase liver damage due to increased production of NAPQI
NSAID nonselective antagonists
piroxicam
tolmetin
indomethacin
ibuprofen
naproxen
meloxicam
most potent nonselective antagonist NSAID to inhibit COX1
piroxicam
most potent nonselective antagonist NSAID to inhibit COX2`
meloxicam
which nonselective antagonist NSAIDs are more selective at inhibiting COX2 pathway?
meloxicam
naproxen
celecoxib and parecoxib are what type of antagonist?
reversible
selective COX-2
how is parecoxib administered?
by injection
adverse effects of selective COX-2 antagonists
risk of myocardial infarction and stroke
hypertension and edema due to inhibition of PG production in kidney
protective effects
thrombosis
acetaminophen MOA
poor inhibitor of COX1 and COX2 in presence of peroxides
inhibits a novel COX splice variant in the brain (COX3)
what type of effects does acetaminophen have?
antipyretic and analgesic
is acetaminophen an anti inflammatory?
no
NAPQI is considered a
BRI
biological reactive intermediate
acetaminophen undergoes _______________ to form NAPQI
CYP450 oxidation
2 classes of DMARDs
traditional
biologic
traditional DMARDs
MTX
leflunomide
hydroxychloroquine
sulfasalazine
cyclophosphamide
cyclosporine
tacrolimus
biologic DMARDs
abatacept
etanercept
infliximab
rituximab
tocilizumab
methotrexate is the ___________ for DMARD therapy
gold standard
treatment and care for osteoarthritis
protecting joints
medication and lifestyle changes
knee injections
knee replacement
joint fusion injury
corticosteroid injections
joint replacement
joint replacement are sometimes considered
treatment of last resort
inflammasome
multiprotein intracellular complex that detects pathogens and sterile stressors
activates highly pro-inflammatory cytokines I-1b and IL-18
what is the best characterized inflammasome?
NLRP3
what does APAP stand for?
N-acetyl-para-aminophenol
acetaminophen is found to inhibit _____________ in the canine brain but its role in humans is not confirmed
COX-1 isoenzyme COX3