pharm: antidysrhythmics

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