Week 5: Antiplatelets, Iron, Folic Acid, and Vitamin B12 Flashcards
1
Q
Aspirin MOA
A
- inhibits thromboxane A2 in the cyclooxygenase pathway thus interfering with platelet aggregation
- COX 1 and COX 2 inhibitor
- salicylated NSAIDs
- inhibits prostaglandins
2
Q
Aspirin ADRs
A
- GI ulcer
- angioedema
- Steven Johnson syndrome
- Reye’s syndrome
3
Q
Aspirin cautions/contraindications
A
- do not use in pediatrics w/ influenza or chickenpox
- low dose used to prevent preeclampsia in pregnancy
- low dose is safe in lactation
4
Q
Aspirin pharmacokinetics
A
- well absorbed with oral intake
- is affected by food
- metabolized in the liver
- renally excreted (pH affects excretion)
5
Q
Clopidogrel (Plavix) MOA
A
- reduces platelet aggregation by inhibiting adenosine diphosphate pathway
- blocks the ADP receptor so that platelets cannot adhere to one another at that receptor
6
Q
Plavix Pharmacokinectics
A
- Prodrug
- metabolized by CYP2C19
- Excreted in urine and feces
7
Q
Clopidogrel (Plavix) Cautions/precautions
A
- avoid in pts with GI ulcers (anti-prostaglandin- prostaglandins are GI protective
- severe hepatic dysfuction - unable to metabolize into active form
- use with PPIs can attenuate (weaken) the antiplatelet effect of Plavix
8
Q
Clopidogrel (Plavix) ADRs
A
- bleeding
- Steven Johnson syndrome (rare)
9
Q
What is the most common iron preparation given because it contains the highest amount of elemental iron?
A
Ferrous sulfate (20% elemental iron) - 65mg of elemental iron in a 325mg tablet - dosing is based on the amount of elemental iron
Ferrous Gluconate - 32mg of elemental iron in a 324mg tablet
10
Q
Iron preparations pharmacokinetics
A
- food affects absorption
- take on an empty stomach
- take with vitamin C to help with absorption
- avoid taking with dairy products, eggs, antacids, calcium which may inhibit absorption
11
Q
Iron preparations ADRs
A
- GI symptoms - constipation, GI upset
- acute iron toxicity with overdose
- keep away from children
12
Q
Iron preparations - monitoring
A
- check reticulocyte count (immature RBCs) 7 to 10 days after starting iron therapy - if this is not back to normal, there is something else wrong
- check and Hgb and Hct at 2 weeks then Hgb, Hct , and ferritin at 3 months
13
Q
Folic acid deficiency - causes
A
- poor dietary intake - absorption issues - increased demand - impaired utilization
14
Q
Folic acid pharmacokinetics
A
- oral, IM, SC are well absorbed
- metabolized by the liver
- excreted in urine and feces
15
Q
Folic acid supplementation indications
A
- treatment of megaloblastic anemia
- prevention of folic acid deficiency
- increased demand during pregnancy, ETOH abuse, hypothyroidism, hemolytic anemia, or malignancy
