Musculoskeletal Flashcards
Aspirin: Mechanism
Irreversible inhibits cyclooxygenase (1 and 2) by acetylation, decreasing synthesis of thromboxane A2 and prostaglandins.
Aspirin’s effect on PT, PTT and bleeding time
Increased BT
No effect of PT and PTT
How much is Aspirin low dose? Usage?
Low dose: < 300 mg/day
Platelet aggregation
How much is Aspirin intermediate dose? Usage?
300-2400 mg/day
Antipyretic and analgesic
How much is Aspirin high dose? Usage?
2400-4000 mg/day
Antiinflammatory
Aspirin: Side effects (6)
Gastric ulceration
Tinnitus (CN VIII)
Chronic Use: Acute renal failure Interstitial nephritis Upper GI bleeding Reye's syndrome after viral
Aspirin: Acid-Base status
Respiratory alkalosis by hyperventilation
Anion gap metabolic acidosis
Where is COX 1 and COX 2 found?
COX1: platelets and GI
COX2: sites of inflammation
Ibuprofen Naproxen Indomethacin Keterolac Diclofenac
NSAIDS
NSAIDS: Mechanism
Reversibly inhibit COX1 and 2 -> blocks prostaglandin synthesis
NSAIDS: Use (3)
Antipyretic
Analgesic
Anti-inflammatory
Indomethacin also closes PDA
NSAIDS: Side effects (3)
Interstitial nephritis
Gastric ulcer
Renal ischemia
COX-2 inhibitors: Mechanism
Reversibly inhibit COX2
Spares COX-1, which helps maintain gastric mucosa and spares TXA1 production
COX-2 inhibitors: Use (3)
RA, osteoarthritis
Patients with gastritis and ulcers
COX-2 inhibitors: Side effects (2)
Increased thrombosis risk
Sulfa allergy
Acetaminophen: Mechanism
Reversibly inhibits COX, mostly in CNS; inactivated peripherally
Acetaminophen: Use (2)
Antipyretic, analgesic
Not anti-inflammatory
Used instead of aspirin to avoid Reye’s syndrome
Acetaminophen: Side effects
Overdose produces necrosis
Depletes glutathione and forms toxic tissue adducts in liver
Treatment for Acetaminophen overdose
N-acetylcysteine
Regenerates glutathione
Alendronate: Family
Bisphosphonate
Bisphosphonate: Mechanism
Pyrophosphate analog
Binds hydroxyapatite in bone, inhibiting osteoclast activity
Bisphosphonate: Use (3)
Osteoporosis
Hypercalcemia
Paget’s disease of bone
Bisphosphonate: Side effects (2)
Osteonecrosis of the jaw (serious dental work) Corrosive esophagitis (take while sitting up)
Not for patients with achalasia
Allopurinol: Mechnanism
Inhibits xanthine oxidase
Decrease conversion of xanthine to uric acid
Allopurinol: Use (2)
Gout
Lymphoma and leukemia to prevent tumor lysis associated urate nephropathy
Allopurinol increases what drug levels?
Azathioprine and 6-MP (both metabolized by xanthine oxidase)
Rasburicase: Mechanism
Urate oxidase to prevent uric acid stones
Febuxostat: Mechanism
Inhibits xanthine oxidase
Febuxostat: Use
Gout
Probenecid: Mechanism
Inhibits reabsorption of uric acid in PCT
Also inhibits secretion of penicillin
Colchicine: Mechanism
Binds and stabilizes tubulin to inhibit polymerization, impairing leukocyte chemotaxis and degranulation
Colchicine: Side effects
GI
When to use glucocorticoids for gout?
First line for renal failure patients
When to use colchicine for acute gout attacks?
when NSAIDS are contraindicated
Etanercept: Mechanism
Fusion protein (receptor for TNFA alpha and IgG1 Fc) TNF decoy receptor
Etanercept: Use (3)
RA
Psoriasis
Ankylosing spondylitis
Infliximab: Mechanism
Anti-TNF-alpha monoclonal antibody
Adalimumab: Mechanism
Anti-TNF-alpha monoclonal antibody
Anti-TNF-alpha MAB: Use (4)
Crohn’s disease
RA
Ankylosing spondylitis
Psoriasis
Anti-TNF-alpha MAB: Side effect
Predispose to reactivation of latent TB
TNF blockage prevents activation of macrophages and destruction of phagocytosed microbes
