Exam #4 part 2

Question 1

Actions of COX (cyclooxygenase)

Answer 1

1. @ site of injury COX catalyzes synthesis of PGe2 & PGi2 which promotes inflammation & sensitizes receptors to painful stimuli
2. in stomach COX catalyzes synthesis of PGe2 & PGi2, which protect gastric mucosa
3. in platelets COX promotes synthesis of thrombin A2 which stimulates platelet aggregation
4. in Kidneys COX catalyzes synthesis of PGe2 & PGi2 which promotes vasodilation thereby maintaining renal blood flow
5. in brain COX derived PG’s in brain mediate fever & also contribute to perception of pain

Question 2

COX-1 Function

Answer 2

↬ Protects gastric mucosa (#2)
↬ Supports renal function (#4)
↬ Promotes platelet aggregation (#3)

Question 3

Beneficial effects of COX-1 inhibitors

Answer 3

↬ Protects against MI & Stroke

Question 4

Harmful effects of COX-1 inhibitors

Answer 4

↬ Gastric ulceration
↬ Renal impairment
↬ Bleeding tendency

Question 5

COX-2 Function

Answer 5

↬ Mediates inflammation (#1)
↬ Sensitizes receptors to painful stimuli (#2)
↬ Mediates fever (#5)
↬ Contributes to perception of pain (#5)
↬ Supports renal function (#4)

Question 6

Beneficial effects of COX-2 inhibitors

Answer 6

Supression of inflammation, alleviation of pain, reduction of fever

Question 7

Harmful effects of COX-2 inhibitors

Answer 7

Renal impairment

Question 8

1st Generation NSAIDs inhibit?

Answer 8

COX 1 & COX 2

Question 9

2nd Generation NSAIDs inhibit?

Answer 9

COX-2

Question 10

1st Generation NSAID types

Answer 10

1. Salicylates: Aspirin, Salicylate Salts
2. Acetic Acids: Indomethacin, Ketorolac
3. Proprionic Acids: Ibuprofen, Naproxen
4. Oxicams: Meloxicam
5. Fenamates: Meclofenamic Acid

Question 11

Aspirin Adverse effects

Answer 11

↬ GI disturbances
↬ Prolonged bleeding time
↬ With high toxic doses = reps. paralysis
↬ Retention of Na & H2O leads to edema
↬ Hyperthermia @ toxic dose
↬ Hypersensitivity Reactions
↬ Reyes syndrome in children - fatal hepatitis w. cerebral edema
↬ Can displace drugs that are highly protein bound causing toxicity of those drugs
↬ Avoid if taking Probenecid (because aspirin ⇣ secretion of uric acid) leads to Gout attack
↬ Pregnancy 1st & 2nd trimester category C, 3rd trimester category D ⇢ close ductus arterioles in baby ⇢ no blood flow

Question 12

Aspirin Indications

Answer 12

⇢ Antipyretic
⇢ Analgesic
⇢ Anti-inflammatory
⇢ TIA's
⇢ Stroke
⇢ MI
⇢ Treats corn, calluses, warts
⇢ Prevents colorectal cancer

Question 13

Acetaminophen action

Answer 13

↝ Inhibits COX 1 & COX 2
↝ Analgesic & Antipyretic properties equivalent to aspirin
↝ Doesn’t work peripherally so it lacks anti-inflammatory effects
↝ Doesn’t cause GI ulceration
↝ Has no effects on renal function & platelets

Question 14

Acetaminophen is a good alternative for which patients ?

Answer 14

↝ Hemophiliacs
↝ Patients with GI ulcers
↝ Children
↝ Patient taking Probenecid for Gout

Question 15

Acetaminophen SE?

Answer 15

Hepatotoxicity from metabolites

Question 16

Antidote for Acetaminophen OD?

Answer 16

N-Acetylcysteine