Pharmacology

Question 1

PGI2

Answer 1

prostacyclin

fxn: decrease plt agg and decrease vascular tone
vs. prostaglandins and thromboxane (other products of AA –> cyclic endoperoxides –> PC, PG, thromboxane) increase plt agg and vasc tone

PG also protect gastric mucosa

Question 2

Acetaminophen

Answer 2

eg Tylenol

REVERSIBLE Cox inhibitor, esp in CNS

antipyretic, analgesic, NOT ANTI-INFLAMM

overdose –> NAPQI buildup in liver, which depletes glutathione and –> hepatic necrosis

Question 3

Aspirin

Answer 3

type of NSAID

IRREV inhib of COX1 and COX2 via acetylation –> decreased PG and thromboxane, increased bleeding time

low dose: decreased plt agg
medium dose: anti-pyretic and analgesic
high dose: anti-inflamm

Can –> gastric ulceration, tinnitus, renal failure, GI bleed etc

Question 4

Celecoxib

Answer 4

COX2 inhibitor (only induced in inflamm cells - targets endoth)

so anti-inflamm and analgesic, but no effect on gastric mucosa or platelets (thromboxane depends on COX1)

Used for RA, OA

Tox: increases risk of thrombosis (disrupts thromboxane:PC balance – increased thromboxane relative to PC –> plt agg)

Question 5

“-dronate”

Answer 5

bisphosphonates (eg Alendronate)

pyrophosphate analogs, so bind hydroxyapatite in bone and inhibit OCs

May –> corrosive esophagitis, osteonecrosis of jaw

Question 6

Teriparatide

Answer 6

PTH analog given daily to increase bone growth (activates OBs > OCs)

Question 7

Chronic gout drugs

Answer 7

Xanthine oxidase inhibitors (allopurinol and febuxostat) - increase conc of azathioprine and 6-MP (usually metabolized by XO)

Pegloticase (uricase that turns uric acid into more water soluble allantoin)

Probenecid (inhibits reabs of uric acid in PCT - may –> uric acid stones)

Question 8

Acute gout drugs

Answer 8

NSAIDs, glucocorticoids, colchicine

Question 9

Salicylates and gout

Answer 9

Don’t give them! Really high doses may increase uric acid clearance, but below that actually suppress clearance

Question 10

TNF-alpha inhibitors

Answer 10

Anti-inflamm, but predispose to infxn

Etanercept (decoy TNF receptor)

Infliximab, adalimumab (anti-TNF-alpha)

Used for RA, psoriasis, IBD, ankylosing spondylitis

Question 11

Action of most leukotrienes and drugs to inhibit them

Answer 11

Increase bronchial tone

Made from AA –> 5-HPETE –> LTC4, LTD4, LTE4 increase bronchial tone

Inhibited by receptor antag Montelukast and Zafirlukast

*vs LTB4 increases neutrophil chemotaxis

**inhibit all leukotrienes by decreasing their synth - Zileuton (asthma drug) decreases AA –> 5-HPETE by inhibiting lipoxygenase