Musculoskeletal Flashcards
what does the lipoxygenase pathway yield?
leukotrienes
action of LTB4
neutrophil chemotaxis
action of LTC4, LTD4, and LTE4
increase bronchial tone
increase vascular permeability
action PGI2 (4)
decrease platelet aggregation
decrease vascular tone (vasodilation)
decrease bronchial tone
decrease uterine tone
action PGE2, PGF2alpha (2)
increase uterine tone
decrease bronchial tone
action TXA2 (3)
increase platelet aggregation
increase vascular tone
increase bronchial tone
mechanism aspirin
irreversibly inhibits COX-1 and COX-2 by acetylation –> decrease synthesis TXA2 and prostaglandins
effect of aspirin on bleeding time, PT, and PTT
increase bleeding time (until new platelets produced – 7 days)
NO EFFECT on PT or PTT
clinical use aspirin at low dose
decrease platelet aggregation
clinical use aspirin at intermediate dose
antipyretic and analgesic
clinical use aspirin at high dose
anti-inflammatory
side effects aspirin
- gastric ulcers
- tinnitus (CN VIII)
- acute renal failure, interstitial nephritis (chronic use)
- upper GI bleeding (chronic use)
- hyperventilation –> respiratory alkalosis (stimulates respiratory centers)
- Reye syndrome in children with virus
what happens if you use aspirin in children who have a viral illness?
Reye syndrome
what effect does aspirin have on pH
respiratory alkalosis (causes hyperventilation)
name some NSAIDs! (5)
- ibuprofen
- naproxen
- indomethacin
- ketorolac
- diclofenac
drug class ibuprofen
NSAID
drug class naproxen
NSAID
drug class indomethacin
NSAID
drug class ketorolac
NSAID
drug class diclofenac
NSAID
mechanism NSAIDs
reversibly inhibit cyclooxygenase (both COX-1 and COX-2) –> block prostaglandin synthesis
clinical use NSAIDs
antipyretic, analgesic, anti-inflammatory
what drug do you use to close a PDA?
indomethacin
side effects NSAIDs
- interstitial nephritis
- gastric ulcer (PGs protect gastric mucosa)
- renal ischemia
mechanism by which NSAIDs can cause renal ischemia
prostaglandins dilate afferent arteriole
name a COX-2 inhibitor
celecoxib
what is celecoxib?
COX-2 inhibitor
mechanism COX-2 inhibitor
reversibly inhibit COX-2 (found in inflammatory cells and vascular endothelium
- -> spares COX-1 –> maintains gastric mucosa
- -> spares COX-1 –> spares platelet function (TXA2 production depends on COX-1)
clinical use COX-2 inhibitor
RA or OA
patients with gastritis or ulcers
side effects COX-2 inhibitor (2)
- increase risk thrombosis
2. sulfa allergy
mechanism acetaminophen
reversibly inhibits cyclooxygenase (mostly in CNS, inactivated peripherally)
clinical use acetaminophen
antipyretic, analgesic
is acetaminophen anti-inflammatory?
NO!!
what should you use instead of aspirin to avoid Reye syndrome in kids with viral infection?
acetaminophen
what happens in acetaminophen overdose
hepatic necrosis
mechanism by which acetaminophen overdose causes hepatic necrosis
acetaminophen metabolite (NAPQI) depletes glutathione and forms toxic tissue adducts in the liver
antidote to acetaminophen overdose
N-acetylcysteine (regenerates glutathione)
what are some bisphosphonates?
alendronate, other -dronates
mechanism bisphosphenates
pyrophosphate analogs –> bind hydroxyapatite in bone, inhibiting osteoclast activity
clinical use bisphosphenates
- osteoporosis
- hypercalcemia
- Paget disease of bone
side effects bisphosphenates (2)
- corrosive esophagitis
2. osteonecrosis of the jaw
what gout drugs are used chronically (preventive)? (3)
- allopurinol
- febuxostat
- probenecid
what gout drugs are used acutely? (3)
- NSAIDs
- glucocorticoids
- colchicine
allopurinol mechanism
inhibits xanthine oxidase –> decrease conversion of xanthine to uric acid
clinical use allopurinol (2)
- chronic (preventive) gout drug
2. lymphoma and leukemia (prevent tumor lysis-associated urate nephropathy)
what drugs does allopurinol increase the concentration of? (2)
- azathioprine
- 6-MP
- -> both normally metabolized by xanthine oxidase
should you give salicylates with allopurinol?
NO!!! all but the highest doses depress uric acid clearance
mechanism febuxostat
inhibits xanthine oxidase
clinical use febuxostat
chronic gout drug (preventive)
mechanism probenecid
inhibits reabsorption of uric acid in PCT
what happens if you take probenecid with penecillin?
inhibits secretion of penicillin in kidney
clinical use probenecid
chronic gout drug (preventive)
which NSAIDs are used as acute gout drugs? (2)
- naproxen
2. indomethacin
clinical use NSAIDs in gout
acute gout drugs
clinical use glucocorticoids in gout
acute gout drugs
mechanism colchicine
binds and stabilizes tubulin to inhibit microtubule polymerization –> impairs leukocyte chemotaxis and degranulation
clinical use colchicine
acute and prophylactic use for gout (mainly actue gout drug)
side effects colchicine
GI
side effects TNF-alpha inhibitors
predispose to infection (including reactivation of latent TB), since TNF blockade prevents activation of macrophages
what is etanercept?
TNF-alpha inhibitor
what is infliximab?
TNF-alpha inhibitor
what is adalimumab?
TNF-alpha inhibitor
name three TNF-alpha inhibitors
- etanercept
- infliximab
- adalimumab
mechanism etanercept
fusion protein (receptor for TNF-alpha and IgG1 Fc) from recombinant DNA
mechanism infliximab
anti-TNF-alpha monoclonal antibody
mechanism adalimumab
anti-TNF-alpha monoclonal antibody
clinical use etanercept
RA, psoriasis, ankylosing spondylitis
clinical use infliximab
IBD, RA, psoriasis, ankylosing spondylitis
clinical use adalimumab
IBD, RA, psoriasis, ankylosing spondylitis