pharm: antidysrhythmics

what do antidysrhythmics do?

what do antidysrhythmics do?

• prolonging the AV node

• increase or decrease conduction speed

• altering ectopic pacemaker

  • group of cells that causes a premature heart beat outside the normally functioning SA node

• altering the SA node

• reducing myocardial excitability

  • inc Na, K can affect

• lengthening the refractory period

  • resting period

• stimulating the autonomic nervous system

vaughan-williams classification

sodium channel

• class 1A, 1B, 1C

beta adrenergic

• class II

potassium channel

• class III

calcium channel

• class IV

miscellaneous

• class V

• digoxin has pos. inotropic effects

all have neg. dromotropic & chromotropic effects

class 1A meds: sodium channel blockers meds

• procainamide (short term)

  • for dysrhythmias at that moment

• quinidine (long term)

  • had dysrhythmias and want to send this med home w/ them

class 1A meds: sodium channel blockers patho

• slows conduction throughout the electrical system in the heart

  • slows down atrial and vent. pumps

• delays repolarization

• ses: SVT, vtach, afib, aflutter

class 1B: sodium channel blockers med

lidocaine

• also used for anesthesia

class 1B: sodium channel blockers patho

• dec electrical conduction & automaticity

• increases rate of repolarization

class 1B: sodium channel blockers uses

• short term for ventricular dysrhythmias like PVCs

  • if multiple = not good = bolus of lidocaine

class 1C: sodium channel blockers med

flecainide

class 1C: sodium channel blockers patho

• this is conduction speed throughout the electrical conduction system

• may also use the valsava maneuver

  • massage carotid

  • submerge hands in cold water

class 1C: sodium channel blockers uses

used for SVT

class II beta adrenergic blockers meds

• propranolol

• esmolol

class II beta adrenergic blockers patho

• prevents SNS stimulation of the heart

• decreases all kinds of things: HR, automaticity through the SA node, velocity conduction through the AV no, myocardial contractility, atrial ectopy

class II beta adrenergic blockers uses

• afib

• aflutter

• PSVT

• HTN

• angina

• PVCs

• MI

class III potassium channel blockers meds

• aminodarone

• sotalol

class II and III properties

class III potassium channel blockers patho

• prolongs action potential (electrical impulse) and refractory period of the cardiac cycle

• reduces automaticity in the SA node, contractility and conduction in the electrical system, dilates coronary blood vessels

• also use epinephrine

• monitor K levels

class III potassium channel blockers uses

• conversion of afib

• vfib

• vtach

• aflutter

class IV calcium channel blockers meds

• verapamil

• diltiazem

class IV calcium channel blockers patho

• depresses depolarization and decreases oxygen demand of the heart

• decreases force of contraction, HR, slows conduction rate of the action potential

• check bp before giving b/c may cause vasodilation

class IV calcium channel blockers uses

• afib

• aflutter

• SVT

• HTN

• angina

class V

• adenosine

  • stops the heart for a few seconds

  • have crash cart nearby

  • has a short half life <10 secs

• digoxin

  • apical pulse for 1 min

  • postive inotropic effect

class V patho

• decreases electrical conduction thru the AV node

class V uses

• PSVT

• SVT

class V complications

• bradycardia

• hypotension

• lightheadedness

class V effectiveness

• ECG normal

• alertness

• absence of symp.

• better contraction

  • inc BP, CO

medications affecting coagulation

• PO/parenteral anticoagulants/SQ

• direct thrombin inhibitors

• direct inhibitors of factor Xa

• antiplatelet meds

• thrombolytic agents

don’t give to pts with ulcers, Crohn’s, ulcerative colitis, women on menstral cycle

assess bleeding (ext. and int.)

• bruising

• blue distended abd.

• tachycardia

• PLT/CBC labs

• lightheadedness

• gum/nose bleeding

• hematuria

• bloody stools

• dec bp

parenteral anticoagulants

• heparin

  • inpatient med

  • monitor labs esp. if IV hep

    • determine if effective

• enoxaparin (lovenox) (low molecular weight heparin)

  • outpatinet

  • less risk for blood clots

parenteral anticoagulants lab values

PTT/aPTT

• IV

  • q6h

  • therapeutic level if 2x normal

    • PTT: 60-70

    • aPTT 20-39

  • inc if not therapeutic

  • dec if too much

  • maintain if stable and labs achieved

    • labs less freq. after 2x normal therapeutic level

  • RN can adjust dose based on results

• subQ

  • no labs

PLT

• can cause heparin induced thrombocytopenia (dec plts)

heparin uses

• acute conditions (anything w/ clots)

  • stroke

  • PE

  • massive DVT

  • MI

heparin patho

• low dose for prophylaxis DVT (prevents clot formations)

• heparin protocol

  • monitor labs

  • change based on therapeutic level

• administration: IV, SQ

  • IV if pt has clot

  • subQ to lower the risk

  • burns more than lovenox

• antidote: protamine sulfate

  • slow IV: no faster than 20 mg/min or 50 mg in 10 mins

• food interactions

  • herbal ginger

  • ginkgo biloba

  • feverfew

  • evening primrose oil increase bleeding risk

heparin complications

• hemorrhage

• HIT (heparin induced thrombocytopenia)

enoxaparin uses

• prevent DVT prophylactically in the hospital setting

• treat DVT and PE

enoxaparin

• low molecular weight heparin (LMWH)

• conjunction with warfarin

• q24 hr dosing

  • longer half-life

  • longer to metabolize

• antidote: protamine sulfate

  • slow IV: no faster than 20 mg/min or 50 mg in 10 mins

• expensive

educating on self administration: enoxaparin

• “bridge therapy”

  • enoxaparin for lower risk of clots but once a clot has formed then heparin used

• use a small gouge needle for administration (25)

  • 90 degrees

• distance 2 inch from the umbilicus

  • burns and bruising can happen

• pinch up an area and insert needle completely

• do not aspirate

• rotate sites

• do not rub injection site

• monitor for bleeding

• pre-filled syringes: do not expel the air

• inject entire contents (as ordered)

• avoid aspirin, NSAIDs

  • inc risk for bleeing

• use electric razor, soft toothbrush

warfarin (coumadin)

• antagonize vit. k, preventing the synthesis of 4 coagulation factors: VII, IX, X and prothrombin

  • consistent intake of greens

  • NO DIET CHANGE

• administration: PO

• protein bound

  • med bounds to protein so don’t inc or dec

• narrow TI

warfarin labs

PT/INR

• PT: 9-12.5

• INR: 1

therapeutic if 2x normal values

warfarin uses

• venous thrombosis

• afib

• prosthetic heart valves

• prevention of recurrent MI, TIA, PE and DVT

warfarin complications

• hemorrhage

• toxicity

  • administer vit. k as an antidote: IV, slowly and in a diluted solution

• if vit. K is ineffective, administer FFP (fresh frozen plasma) or whole blood

warfarin contraindications

• prior to surgeries or procedures

• preg. risk X

  • heparin is better for preg. patients

• pt with low platelet count

  • thrombocytopenic pts

• interacts with many meds

  • contraceptives, anticonvulsant, etc

• do med reconciliation

  • know drug interactions

foods in high in vit.K

• spinach

• canola oil

• romaine lettuce

• mayo

• iceberg lettuce

• broccoli

• brussel sprouts

parenteral anticoagulants nursing considerations

• heparin and warfarin

  • consistently take at same time

  • full therapeutic effect in 3-5 days

  • when discharging and the pt has schedules heparin and warfarin since they are going home with warfarin and not heparin, they would still take the heparin and the warfarin b/c warfarin takes 3-5 days to take full effect

• PT/INR

  • 2-3 (afib)

  • 3-4.5 (heart valves)

• advise pts to move around to avoid clots forming

• use a soft-bristle toothbrush to avoid gum bleeding

direct thrombin inhibitors meds

• dabigatran

• bivalirudin

• desirudin

dabigatran (pradaxa) patho

• prevents thrombus from developing

• advantage: less blood work monitoring

• antidote: idarucizumab (praxbind)

dabigatran uses

• prevents stroke from afib

• treat DVT

• prevent PE

dabigatran complications

• bleeding

• GI effects

bivalirudin patho

• used to prevent blood clots during angioplasty

desirudin patho

• used for pts having hip replacements

antidote for direct thrombin inhibitors

none

direct inhibitor of factor Xa meds

• rivaroxaban (xarelto)

• apixaban (eliquis)

direct inhibitor of factor Xa uses

• afib

• prevention of DVT and PE in pt undergoing hip or knee arthroplasty

direct inhibitor of factor Xa patho

• prophylaxis for stroke and embolism in afib

• monitor h&h, LFTs periodically

• antidote: andexanet alfa (andexxa)

  • if starting to bleed

antiplatelets

• antiplatelet/salicylic

• antiplatelet/glycoprotein inhibitor

• antiplatelet/ADP inhibitor

• antiplatelet/arterial vasodilator

antiplatelet/salicylic med

aspirin

• targets clot itself, destroys PLTs

antiplatelet/salicylic uses

• prevention of

  • MI

  • reinfarction

  • stroke

  • TIA

antiplatelet/salicylic complications

• GI upset: NSAIDs

• prolonged bleeding time

• tinnitus

• hearing loss

• ototoxicity

minimize use of other meds which enhance bleeding

• one antiplatelet and one anticoag = don’t add more cause inc risk for bleeding

antiplatelet/glycoprotein inhibitor med

IV infusion

• eptifibatide (integrilin)

antiplatelet/glycoprotein inhibitor uses

• acute coronary syndrome

• cardiac catherizations

cardiac specific

antiplatelet/glycoprotein inhibitor antidote

none

antiplatelet/glycoprotein inhibitor complications

• hypotension

• bradycardia

• prolong bleeding time

antiplatelet/glycoprotein inhibitor nursing considerations

• monitor cardiac catheterization access site; apply pressure

• monitor for gastric bleed, bruising, petechiae, bleeding gums

antiplatelet/glycoprotein inhibitor patho

glycoprotein is given to connect the plts together therefore glycoprotein inhibitors prevent the connection of plts

antiplatelet/ADP inhibitor meds

• clopidogrel (plavix)

• pasugrel (effient)

antiplatelet/ADP inhibitor patho

ADP are receptors on the walls of plts that help plts stick together, ADP inhibitors prevent the receptors from binding to each other so glycoprotein will not form either

antiplatelet/ADP inhibitor uses

• acute coronary syndrome

• prevention of ischemic stroke

• TIA

• MI

• re-infarction

usually, pts start after coronary angiography with stent placement

antiplatelet/ADP inhibitor complications

• prolonged bleeding time

• gastric bleed

• thrombocytopenia

• GI effects

antiplatelet/ADP inhibitor contraindications

• pts with bleeding disorders

• peptic ulcer disease

• intracranial bleed

• thrombocytopenia

• use cautiously with other meds that enhance bleeding

• stop 7 days before surgery

• herbal supplements

  • ginger, ginkgo, biloba, feverfew, and evening primrose oil inc bleeding risk

antiplatelet/arterial vasodilator meds

• pentoxifylline

  • enhances O2 cap. carry in RBCs

• dipyridamole

antiplatelet/arterial vasodilator uses

• commonly used for pts with PAD

• intermittent claudification

  • cramping in leg caused by exercise

antiplatelet/arterial vasodilator complications

GI upset

thrombolytic meds

• alteplase (activase)

  • aka TPA: tissue plasminogen activator

• tenecteplase

• reteplase

thrombolytic patho

• dissolves clots

• converts plasminogen to plasmin, which destroys fibrinogen and other clotting factors

thrombolytic uses

• MI (when cath lab isn’t available)

• massive PE

• ischemic stroke

• restore patency to central IV lines

• PAD w/ embolic clots in different vessels

thrombolytic complications

serious risk of bleeding

thrombolytic nursing considerations

• limit venipuncture and injections

• apply pressure dressings to recent wounds

• monitors for changes in patient’s condition

• monitor h&h, aPTT, PT

thrombolytic contraindications

HTN

• rupture of vessels = internal bleeding

• if in the brain = hemorrhagic stroke

joint commission core measures for an MI

• aspirin on arrival to ER/prescribed at discharge

• BB at discharge

  • dec size of infarction

• statin at discharge

  • LDL <100

• ACE/ARB at discharge for LVSD

acute coronary syndrome (ACS) AHA

• treatment of ACS involves the initial use of drugs to relieve ischemic discomfort, dissolve cots, and inhibit thrombin and platelets

• oxygen

• aspirin

• nitroglycerin

• opiates

  • morphine

  • sedative, anti-anxiety, pain

• fibrinolytic therapy

• heparin