Medications to prevent blood clots

Coagulation

clotting

Coagulation pathway

extrinsic or tissue factor pathway

intrinsic or contact activation pathway

common pathway

Extrinsic or tissue pathway

activated when blood leaks out of a vessel and enters tissue spaces

uses tissue factor which is not found in the blood

fast

PT, vitamin K

Intrinsic or contact activation pathway

activated in response to injury

all of its factors (proteins) are found in the blood

slow

aPTT, heparin

Common pathway

form a clot

Blood clot

semi-solid mass of blood

thrombus- stationary clot

embolus- traveling clot

two types:

• arterial- symptoms are immediate

• venous- symptoms are gradual

Blood clots and clinical manifestations

1. heart= myocardial infarction. chest pain/pressure, numbness and tingling, diaphoresis

2. Lungs= pulmonary embolism (PE). Sudden dyspnea, tachycardia, coughing up blood (hemoptysis)

3. Brain= cerebral vascular incident (CVI). FAST- unilateral face droop, arm weakness, slurred speech, (T= “time is brain” seek help immediately)

4. Deep vein thrombosis (DVT). unilateral swelling, warmth, erythema. usually in lower extremities

anticoagulants

used to prolong bleeding time

do not change blood viscosity- not really “blood thinner”

used primarily to prevent thrombosis in veins

bleedin gprecautions

No NSAIDS - ibuprofen, Motrin

electric razor

soft bristle toothbrush

stool softeners/high fiber diet/fluids

decrease needle sticks/smallest gauge possible

avoid contact sports

education- when to call MD

any unexplained, severe or uncontrollable bleeding; bleeding that lasts a long time

unusual or unexplained bruising

coughing up or vomiting blood; or vomit that looks like coffee grounds

pink or brown urine; red or black stools (looks like tar)

unexplained pain or swelling of joints

headaches, weakness, or dizziness

oral anticoagulants

warfarin (coumadin)

dabigatran (pradaxa)

apixaban (eliqus)

rivaroxaban (xarelto)

warfarin (coumadin)

must take medication at same time every day

• 3-4 days for effectiveness and 3-4 days for natural clotting pathway to restore after discoutination

do not suddenly change diet to include or decrease vitamin K rich foods after the medication is calibrated

highly protein bound= longer duration of action

antidote= vitamin K (take 6hrs for effectiveness)

Vitamin K rich food

avocado, green apples, green grapes, honeydew, kiwi, limes, green pears, artichokes, arugula, asparagus, broccoli, broccoli rabe, brussels sprouts, napa cabbage, green beans, cabbage, celery, cucumber, kale, belgian endive

therapeutic PT

18-30sec

INR

2-3

high: pt >30sec or INR >3

bleeding risk

Low: PT <18 sec or INR <2

clotting

warfarin drug interactions- increase effectiveness

aspirin, cimetadine (tagamet), clopidogrel (plavix), Heparin, NASIDS, Cephalosporins, Macrolides, Fluoroquinolones, Piperacillin/Tazobactam

warfarin drug interactions- decrease effectiveness

some oral antidiabetic agents (glucophage, metformin, rifampin)

rivaroxaban (Xarelto)/ apixaban (eliquis)/ Dabigratan (pradaxa)

1. few drug/drug or food/drug

2. use for a-fib (not if valve issues) and DVT prevention

3. no need for INR or PT monitoring

4. baseline lover function and CBC for platelets

5. antidotes now available

Heparin

most common

chemical naturally found in liver and lining of blood vessels

sub Q or IV (never IM, no aspirate or massage)

abdomen= preferred site

Heparin- Nursing considerations

monitor aPTT- therapeutic level= 50-80

watch for bleeding

watch for thrombocytopenia

antidote = protamine sulfate

low molecular weight heparin

dalteparin (fragmin)

enoxaparin (lovenox)

made with pork derivatives. watch pork allergies and cultural and religious objections to pork

Aspirin

discontinue at least 7 days prior to surgery

clopidogrel (plavix)

ADP receptor blocker

ADP causes platelets to change shape and congregate. Clopidogrel stops this “clumbing”

discontinue 5 days before surgery

Black Box Warning: needs a specific P450 enzyme that some people do not have