Drugs Affecting the Blood
NSG 220
by Unknown Author is licensed under
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Types of Drugs
Thrombolytics
“Clot Busters”
Highest Bleed Risks
Anticoagulants
Treat and prevent thrombosis “clot”
MOA (mechanism of action)- Inhibits Vit. K in the liver that interferes with the blood clotting mechanism by blocking thrombin
Antiplatelets
Lower platelet aggregation
Mechanism of action- prevent platelets from clogging up
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Antiplatelets
Indicated for: Ischemic strokes, TIA (transient ischemic attacks), unstable angina, coronary stenting, Acute MI, previous MI & prevention of MI
Aspirin “salicylic acid” ASA
PO, IV and rectal preparations
Too much “ASA toxicity”
Tinnitus- ringing in ears- high doses or long-term use
Elevated blood pressure and tachycardia –possible bleed
Contraindicated for patients with thrombocytopenia
Clopidogrel (Plavix)- po only
Indicated for: Strokes (CVA), prevent stenosis of coronary stents
Takes effect with 2 hrs. of the first dose, peak effect 3-7 days of treatment
Administered with PPI (proton-pump inhibitors) such as Omeprazole to prevent GI bleeding, however, can also reduce the efficacy of Clopidogrel
Discontinue at least 5 days before surgery d/t bleeding risk
Dipyridamole (po & IV)
Indicated for prevention of thromboembolism following heart valve replacement
given w/other antiplatelets- Aspirin
Aside effects- headache, dizziness, & GI disturbances
Ticlopidine (po)
Indication: CVA prevention and coronary artery occlusion
Can be given with aspirin or for patients who can not take aspirin
Platelets (thrombocytes) are cells in the blood that clump together to begin the clotting process. They are the first responders when there is injury. They also initiate the inflammatory response of the innate immune system. The four main platelet functions are:
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Antiplatelets
Prevent platelets from forming clots, DO NOT decrease the number of clots
Indication: post MI/ACS or to prevent MI, CVA, TIA, PAD (peripheral artery disease) & prevent re-occlusion of vessels
Before you administer the medication
Monitor labs
Hemoglobin- if less than 7
Platelets – (150,000-400,000)
***less than 150K- Call the provider, *less than 50K- Urgent
Hold the medication for abnormal labs, Notify the provider
Anticoagulants
Drugs used to prevent and treat “thrombosis”
Venous thrombi “stagnate” develop when blood flow is slow – when blood settles, fibrin is produced causing the red blood cells and platelets to form a thrombus.
Thrombosis- 2 types
Venous-blood clot in the vein
Venous thrombus has a tail that can break off causing an embolus
Embolus can travel to the lungs causing a pulmonary embolism
Arterial- blood clot in the artery.
Harmful effects are local causing blockage and decrease perfusion to area or organ(s)
Anticoagulants
Used for: prevention growth of “existing clots and/or new clots”
Do not dissolve clots
Indicated for: prevention of DVT
MOA: blocks the formation of fibrin (forms seals on clots)
Administration: IV or subcutaneous
Monitor Labs: pTT (46-70)
(the lower the number the thicker the blood, the higher the number the thinner the blood)
**Dosage of medication will be based on these labs.
Anticoagulant Drugs
Heparin (Administered IV or subcutaneous
MOA: Activation of antithrombin, resulting in the activation of factor Xa and thrombin
Prescribed short-term (days to weeks)
Works quickly within minutes (usually 20mins)
Usually given for DVTs or after MI (heart attack) to prevent clots from growing
Low Molecular Weight heparin (Enoxaparin and Dalteparin)
MOA: Activation of antithrombin, resulting in the activation of factor Xa and thrombin and some activation of thrombin
Administered subcutaneous only (never aspirate or rub the site)
Patient can administer this medication at home
Assess H & H (hemoglobin and hematocrit) and blood pressures that drop by 20 points
Monitor platelets – ***HIT**
Warfarin (po only)
MOA: Activation of antithrombin, resulting in selective inactivation of factor Xa
Takes days to take effect (usually 5 days) but last a long time once taken
Life-long therapy – Most patients have to take it rest of their life was started
Monitor labs for frequently (daily for 5 days) for therapeutic ranges (INR, but also Prothrombin time (PT)
Clinical Pearl- A patient who is started on heparin in the hospital can start taking coumadin. They CAN be taken at the same time.
Patients who take warfarin will often be referred to coumadin clinics. Where there labs are monitored frequently
Monitor for HIT (half of the platelets are decreased with 24 hours after starting heparin/low molecular heparin
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Monitor
Labs
Heparin – monitor aPTT
If ptt is over 70 stop the heparin drip
Any signs of bleeding (iv site, urine) stop the infusion- notify provider
Antidote – protamine sulfate
Warfarin- monitor INR
Antidote – Vitamin K ***do not give Vit K unless the patient has had warfarin for 5 days (after switching from IV Hep)
Teach patient to eat vit K in moderation when eating.
Eat leafy green vegetables and foods such as liver.
Bacteria in the intestine produces vitamin K. When antibiotics are taken, they kill the bacteria and
Antibiotics increase INR.
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Thrombolytics
Used to treat emergency conditions: CVA (cerebral vascular accident), MI (myocardial infarction, PE (pulmonary embolism) & other conditions (i.e., clot removal from central line or dialysis catheter)
Medications: Alteplase, Reteplase, Tenecteplase
MOA: break down, or lyse of fibrin in thrombi (usually dissolve newly formed clots)
Administration: IV only
**only drug that dissolves clot**
Usually given within 3-4.5 hours from onset of symptoms
No new injections at all. The IV’s (usually 2) is what you will use. No other injections. Never through central lines
If you make the H for heparin it looks like 2 tt’s crossed. You can use this to remember which lab to watch
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Memory Tricks
Anticoagulants
Platelets 150K-400K
<150 K
<50 K critical low = “Thrombocytopenia”
Heparin
pTT – “2 t’s make the letter H”
46-70 pTT
Warfarin (in=“IN”r)
INR 2-3 Therapeutic Range
Antiplatelets – monitor “platelets”
clopidogrel
Aspirin
Abciximab
Memory Tricks (cont.)
AVOID any patients with active bleeding
with liver problems because liver makes coagulation factors (vitamin K). No vitamin K (clotting factor= risk of bleeding)
Peptic ulcers (bleeding)
Think about any situations that can cause or a concern for bleeding (i.e., medications, disease process, sign or symptoms of bleeding)
Patient teaching
Safety
Environment (situations in which patient can injure themselves) rugs, dim rooms
Patient care
Soft bristle toothbrushes, no razors, no flossing, avoid constipation, no alcohol-based mouth wash,
Always wear a medical alert bracelet
Avoid trauma where injuries can occur