Pharm Final Flashcards
Standard drug therapy are for anticoagulants for pt with afib
Warfarin/ Coumadin therapy should be used based on the patient’s CHAD
Score; Chad Scores assign 1 point each for CHF, Age, Diabetes, and two
points for a previous stroke, or TIA.
MOA of warfarin
Coumadin (Warfarin) inhibits the formation of vitamin k dependent clotting factors.
Hepatic synthesis of coagulation factors II, VII< IX, and X as well as protein C and S requires the presence of vitamin K. These clotting factors are biologically activated by the addition of carboxyl groups to key glutamic acid residues within the protein’s structure. In the process “active” vitamin K is oxidatively converted to an inactive form, which is then subsequently reactivated by vitamin K epoxide reductase complex I (VKORC1). Warfarin competitively inhibits the subunit 1 of the multi unit VKOR complex, thus depleting functional vitamin K reserves and hence reduces synthesis of active clotting factors. The onset of action for anticoagulation for the oral dose is 24-72 hours. Peak effect: full therapeutic effect is in 5-7 days, INR may increase in 36-72 hours. Half life elimination mean is 40 hours.
Anticoagulants With Pregnancy Risk Factor X
Warfarin (Coumadin): Pregnancy Risk Factor X
MOA of Plavix
The mechanism of Action: clopidogrel (Plavix) requires in vivo
biotransformation to an active thiol metabolite. The active metabolite irreversibly blocks the P2Y12 component of ADP receptors on the platelet surface, which prevents activation of the GPIIb/ IIa receptor complex, thereby reducing platelet aggregation. Platelets blocked by Clopidogrel (Plavix) are affevted for the remainder of their lifespan, approximately 7- 10 days. Onset occurs within 2 hours, and half life elimination is about 6 hours.
Know the most commonly reported and serious adverse drug reactions with Dabigatran (Pradaxa) therapy
Adverse reactions include gastrointestinal dyspepsia, hematologic bleeding, anemia, and a black box warning when used in patients to prevent stroke with non-valve Afib. There I an increased risk of stroke that may occur upon discontinuation of the drug if the patient is not adequately anticoagulated with an alternative anticoagulant. Also increased risk of bleeding in high risk patients. The most common complication is bleeding, and sometimes fatal bleeding.
Know what type of drug is Warfarin
Oral Anticoagulant
Dietary restrictions with Warfarin
Foods with high vitamin K
Green Leafy Veggies
Green tea,
Chewing tobacco,
a variety of oils (canola, corn, olive, peanut, safflower, sesame seed, soybean and sunflower).
Snack foods containing Olestra have 80 mg of vitamin K added to each once.
Some natural products may contain hidden sources of vitamin K.
- Know what the least expensive antiplatelet drug is on the market
Aspirin (Brand names many e.g., Bayer)
Pricing: Cost: (81 mg once daily for 30 days is $3.50 and 325 mg is $14.55)
Warfarin versus NOAC/DOAC’s
For patients in whom cost is a potential adherence barrier, consider warfarin.
Know what drug therapies patients could be placed on that do not want INR testing
Direct Oral Anticoagulant Drugs = DOAD’s
Apixaban - (Eliquis)
Dabigatran - (Pradaxa)
Rivaroxaban - (Xarelto)
DOAD’s
Direct Oral Anticoagulant Drugs
Know the concurrent drug therapy issues with Plavix
Anticoagulants
Aspirin
CYP2C19 inhibitors
PPIs (Proton Pump Inhibitors)
Until solid evidence exists to support staggering PPIs with Clopidogrel, the dosing of PPIs should be altered (Plavix dosage may need to be increased to 150mg once daily)
Know how to manage a patient on Warfarin therapy when INR at desired range
INR testing can be 4-6 weeks
o INR should be 2-3
o Mechanical mitral valve 2.5-3.5
Know how to manage a patient on Warfarin therapy if INR elevated
INR + 3.5
Decrease weekly dose by 5% - 15%
Repeat INR 3X weekly until therapeutic
INR + 4.7
Hold 1 dose, Decrease weekly dose by 10% - 20%
Repeat INR 3X weekly until therapeutic
INR + 5.2
Hold 2 dose, Decrease weekly dose by 10% - 20%
Repeat INR 3X weekly until therapeutic
INR + 5.2 & Need to reverse
Vit K 2.5mg PO X 2 or 3mg SQ or IV (slow)
Know what advise to give a patient with a drug eluding stent on Plavix and ASA
**Controversial Duration of Clopidogrel (in combination with aspirin) after stent placement:
Premature interruption of therapy may result in stent thrombosis with subsequent fatal and nonfatal MI.
With STEMI, Clopidogrel for at least 12 months regardless of stent type (e.g., either bare metal or drug eluting stent) is recommended.
Know the recommended drug therapy for H. pylori
Any PPI
Clarithromycin 500 mg orally every 12 hours
Amoxicillin 1 g orally every 12 hours
OR
Metronidazole (Flagyl) 500 mg orally every 12 hours.
Treatment of triple therapy is for 14 days.
Know the MOA for PPIs
MOA: These drugs suppress gastric basal and stimulated acid secretion by inhibiting the parietal cell H+/K+ ATP pump
Know the MOA of H2 Blockers
MOA- competitively and reversibly bind to H2 receptors on parietal cells to suppress acid secretion. These agents primarily reduce basal acid secretion and thus are most effective when administered in the evening. H2 blockers are effective in the treatment of uncomplicated GERD, in promoting the healing of gastric and duodenal ulcers, and for the prevention of stress ulcers. Vitamin B12 deficiency (monitor levels)
Know first line drug therapy for GERD
Phase I: Lifestyle and diet modifications, antacids plus H2 blockers or PPIs
Phase II: Symptoms persist, consider endoscopic evaluation
Phase III: Surgery
Know when H2 Blockers should be taken
Once daily taken at night to control night-time acid reflux
Know which ethnic group may need adjustment in their PPI drug therapy because of the presence of the CYP2C19 genotype?
Asians may experience increased efficacy or risk of toxicity due to the presence of the CYP2C19 genotype, which is associated with slower metabolism of proton pump inhibitors.
