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

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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

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

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

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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

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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

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^^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

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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

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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

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