Download Cardiac Drugs Part II

Cardiac Drugs Part II
Diuretic Drugs
Coagulation Modifier Drugs
Antilipemic Drugs
The Kidney
Nephron

The microscopic filtration unit of the kidney,
consisting the glomerulus, proximal
convoluted tubule, loop of Henle, distal
convoluted tubule, collecting duct, which
empties urine into the ureters.
Glomerular Filtration Rate



GFR
Is a laboratory value the serves as a gauge of
how well the kidneys are functioning as
filters.
180 liters of blood filtered through kidneys per
day.
Diuretic Drugs

All major classifications developed between
1950 and 1970 and are the most commonly
prescribed drugs in the world.
Diuretic Drugs

Classified according to site of action
Classifications of Diuretics
1.
2.
3.
4.
5.
Carbonic Anhydrase (Diamox): acts on the
nephrons
Loop diuretics (Lasix): acts on the loop of
Henle
Osmotic diuretics (Mannitol): works in the
kidney on the glomerular filtration
Potassium sparing (Spiraldactone): works in
the distal tubules
Thiazides (Diuril): works in distal tubules
1. Carbonic Anhydrase Inhibitors



Action: inhibit the action of the enzyme
carbonic anhydrase.
Site of action: nephrons
Indications: glaucoma, edema, epilepsy, and
high altitude sickness.
Carbonic Anhyrase Inhibitors

Contraindications:



Drug allergy
Severe renal or hepatic dysfunction
Adrenal gland insufficiency
Adverse effects





Drowsiness
Anorexia
Paresthesias
Hematuria (blood in urine)
Melena (blood in stool)
Interactions



Increase in digoxin toxicity in clients taking
digoxin.
Corticosteroids may cause hypokalemia.
Use with hypoglycemic drugs in diabetic type
2
Acetazolamine



Trade name: Diamox
Classification: carbonic anhyrase inhibitor
Caution: check with patient regarding drug
allergy to sulfonamides or significant liver or
renal dysfunction.
Dosing


Oral dosage for adults is 250 to 375 mg / day.
Oral dosing for pediatric patient is 5 mg / kg
/day.
2. Loop Diuretics



Potent diuretics
The drugs act primarily along the thick
ascending limb of the loop of Henle, blocking
chloride and sodium resorption.
Also activate renal prostaglandins which
results in dilation of blood vessels in kidneys
and lungs and rest of body.
Loop Diuretics



Used when rapid diuresis is needed.
Onset of action is1 hour and duration is 1-2
hours.
Usually given in a single daily dose
Major Side Effect



Electrolyte imbalance
Especially sodium and potassium
Nurse alert: always check serum potassium
and sodium levels before administering.
Good Effects of Loop Diuretics





Reduces blood pressure
Reduces pulmonary vascular resistance
Reduces systemic vascular resistance
Reduces central venous pressure
Reduces left ventricular end-diastolic
pressure.
Contraindications


Drug allergy
Allergy to sulfonamides
Furosemide





Trade name: Lasix
Therapeutic classification: diuretic
Pharmacologic classification: loop diuretic
Primary use: pulmonary edema and edema
associated with heart failure, liver disease
and nephrotic syndrome.
Used in treatment of hypertension caused by
heart failure.
Lasix Dosing

Adult: IV 0.5 to 1 mg / kg / dose (maximum
200 mg / day.
Drug calculation problem




Client weighs 170 pounds
Convert pounds to kilograms _________
Safe range of drug _______ to _______
Physician order: 56 mg of Lasix IV STAT
Drug calculation problem


Lasix is provided as 10 mg / mL
How much would you need to draw up to give
the 56 mg?
3. Osmotic Diuretics

Action: increases the osmotic pressure of the
glomerular filtrate inhibiting the reabsorption
of water and electrolytes.
When Used?


Oliguric phase of acute renal failure.
Increased intracranial or intraocular pressure.
mannitol



Trade name: Osmitrol, Resectisol
Therapeutic classification: diuretic
Pharmacologic classification: osmotic diuretic
mannitol adverse effects





CNS: confusion and headaches
EENT: blurred vision
Cardiovascular: transient fluid expansion,
chest pain, CHF, pulmonary edema,
tachycardia
GI: Nausea, vomiting and thirst
GU: urinary retention
Dosing

Adult dosing: 500 mg / kg (Given in
intravenous solution)



Onset 30 to 60 minutes
Peak 1 hour
Duration 6-8 hours
Nursing Assessment



Monitor vital signs
Urine output
Signs and symptoms of dehydration




Decreased skin turgor
Fever
Dry skin and mucous membranes
Low urine output
4. Potassium Sparing Diuretics


Also called aldosterone-inhibiting diuretics
because they block the aldosterone
receptors.
This causes sodium and water to be excreted
and potassium to be retained.
Potassium Sparing Diuretics

Action: drugs work in the collecting ducts and
distal convoluted tubules, where they
interfere with sodium-potassium exchange.
Indications

Used with other agents to treat edema or
hypertension
Contraindications and Precautions



Use with caution in geriatric or debilitated
patients or patients with diabetes mellitus
(increased risk of hyperkalemia).
Renal insufficiency (BUN >30
History of gout or kidney stones
Adverse Reactions / Side Effects



CNS: dizziness, clumsiness, headache
Gastrointestinal: cramps, nausea, vomiting,
diarrhea
Other: urinary frequency, weakness,
hyperkalemia.
spironolactone



Trade name: Aldactone
Therapeutic classification: diuretic
Pharmacological classification: potassiumsparing diuretic
Aldactone



Onset: unknown
Peak: 2-3 days
Duration: 2-3 days
Dosing

PO Adults


25-400 mg per day as a single dose or 2-4 divided
doses.
PO Children

1-3 mg / kg / day. Daily or 2-4 divided doses.
5. Thiazides and Thiazide-Like
Diuretics



Action: increases excretion of sodium and
water by inhibiting sodium reabsorption in the
distal tubule.
Therapeutic effects: Lowering of blood
pressure in hypertensive patients and
diuresis with mobilization of edema.
Often the first drug used to lower blood
pressure.
Contraindications


Allergy to sulfonamides
Used cautiously in clients with renal or severe
hepatic impairment.
Adverse Reactions and Side Effects


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CNS: dizziness, drowsiness, lethargy and
weakness
CV: hypotension
GI: anorexia, cramps, hepatitis,
Dermatology: photosensitivity, rashes
Fluid / electrolytes: Hypokalemia,
dehydration, hyponatremia
MS: muscle cramps
hydrochlorothiazide



Trade name: Esidrix, HydroDIURIL
Therapeutic classification: antihypertensive,
diuretic
Indication:


management of mild to moderate hypertension
Treatment of edema associated with CHF, renal
dysfunction, cirrhosis, corticosteroid therapy,
hormonal therapy
Dosing


PO adults: 250 mg – 1 gram / day as a single
dose or in divided doses
PO children > 6 months: 10-20 mg/kg/day as
a single dose or in divided doses.
HydroDIURIL



Onset 2 hours
Peak 3-6 hours
Duration 6-12 hours
Laboratory Considerations

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Electrolytes especially potassium
Blood glucose
BUN
Serum Creatinine
Uric acid
Coagulation Modifier Drugs
Chapter 27
Anticoagulant

A substances that prevents or delays
coagulations of the blood.
Antiplatelet Drugs

A substance that prevents platelet plugs from
forming, which may be beneficial in defending
the body against heart attacks and strokes.
Anticoagulants


Prevent the formation of a clot by inhibiting
certain clotting factors called anticoagulants.
Only given prophylactically because they
have no direct effect on a clot that has
already formed.
Clots / Embolus

Clot: Insoluble solid elements of blood that
have chemically separated from the liquid of
plasma component of the blood.

Embolus: a blood clot that has been
dislodged from the wall of a blood vessel and
is traveling throughout the bloodstream.
Anticoagulants

Also called antithrombotic drugs because
they all work to prevent the formation of clots
or thrombus.
Embolus



Stoke or cerebral vascular accident occurs
when a blood clot travels to the brain.
Pulmonary embolism occurs when a blood
clot travels to the lungs.
Deep vein thrombosis or DVT: clot in the
veins of the legs.
Anticoagulants

All anticoagulants work in the clotting
cascade, but do so at different points.
Heparin



Therapeutic classification: anticoagulants
Pharmacologic classification: Antithrobotic
Action of heparin is to turn off the coagulation
pathway and prevent clots from forming.
Indications

Prophylaxis and treatment of various
thromboembolic disorders including:

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Venous thromboembolism
Pulmonary embolism
Atrial fibrillation with embolization
Acute and chronic coagulopahties
Used in low doses to maintain patency of IV
catheters (heparin flush)
Contraindications

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Uncontrolled bleeding
Severe thrombocytopenia
Open wounds
Use with caution:

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Severe liver or kidney disease
Untreated hypertension
Ulcer disease
Spinal cord or brain injury
Heparin

Use with extreme caution:

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Severe uncontrolled hypertension
Bacterial endocarditis
Bleeding disorders
Hemorrhagic stroke
GI bleeding / ulcers
Recent CNS or ophthalmologic surgery
Drugs that interact with heparin


Aspirin (salycilates)
NSAIDs
Dosing

IV adults:

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Intermittent bolus: 10,000 units followed by 5000 –
10,000 units q 4-6 hours
Continuous drip: 5000 units (35-70 units / kg)
SubQ: 800 to 10,000 units q 8 hours or 15,000 to
20,000 units every 12 hours
IV children:

Intermittent bolus: 50 units / kg followed by 100
units / kg q 4 hours.
warfarin

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Trade name: Coumadin
Therapeutic classification: antigoagulants
Pharmacologic classification: coumarins
Action: Interferes with hepatic synthesis of
vitamin K – dependent clotting factors (II, VII,
IX and X)
Used to prevent thromboembolic events
Adverse Reactions and Side Effects



GI: cramps and nausea
Derm: dermal necrosis
Hemat: Bleeding
Dosing


PO adults: 2.5 – 10 mg / day for 2-4 days and
then dose adjusted by results of prothrombin
time (PT) or international normalized ration
(INR).
Use lower doses in the geriatric population.
Laboratory Values

Prothrombin time (PT): measures how long it
takes a clot to form in a sample of blood.


PT 1.3 to 1.5
International normalization rate (INR): a
standardized measure of coagulation
achieved by drug therapy.

INR of 2.0 to 3.0
Nursing Responsibilities

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Take exactly as directed
If a dose is missed take as soon possible
Do not double up on doses
Review food high in vitamin K
Vitamin K is antidote for warfarin overdose
Instruct on brushing teeth with soft brush.
Report any unusual bleeding or bruising
Foods high in Vitamin K

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Green leafy vegetables
Prunes
Noodles: spinach
Pie crusts
enoxaparin
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Trade name: Lovenox
Therapeutic classification: anticoagulant
Pharmacologic classification: antithrombotic
A prototype of heparin – replacing the use of
heparin since laboratory values do not need
to be monitored so tightly.
Lovenox


Action: Potentiates the inhibitory effect of
antithrombin on factor Xa and thrombin.
Used to control formation of emboli
production post surgery.
Dosing


DVT prophylaxis before knee / hip surgery
30 mg SC twice a day starting within 24
hours post-op and continuing for 7 – 10 days
or until ambulating.
Deep Vein Thrombosis
Nursing Assessment

Assess for signs of bleeding and hemorrhage

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Bleeding gums
Nose bleed
Unusual bleeding
Black tarry stools
Hematuria
Fall in hematocrit
Bleeding from surgical site
Antiplatelet Drugs

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

Generic name: salicylates
Trade name: Aspirin and aspirin
combinations
Indication: prophylaxis of transient ischemic
attacks and myocardial infarct.
Action: decreased platelet aggregation.
Antilipemic Drugs
Chapter 28
Cholesterol

A fat-soluble crystalline steroid alcohol found
in animal fats and oils and egg yoke and
widely distributed in the body especially in the
bile, blood, brain tissue, liver kidneys, adrenal
glands and myelin sheaths of nerve fibers.
Cholesterol Levels


LDL: low density cholesterol
HDL: high density cholesterol (good
cholesterol)
Why is high LDL a problem?


Atherosclerotic plaque formation
High correlation between Coronary Artery
Disease (CAD) and high LDL and low HDL.
Treatment Guidelines

Current guidelines recommendations:



LDL levels exceeding 190
LDL levels of 160 to 190 with CAD
Other risk factors

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Waist circumference greater than 40 inches
Serum triglycerides of 150 or greater
HDL cholesterol less than 40
Blood pressure of 130/85 or higher
Fasting serum glucose greater than 110
Statins

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

A class of cholesterol-lowering drugs that are
more formally known as HMG-CoA reductase
inhibitors.
First classification developed in 1987.
Action: lower the blood cholesterol by
decreasing the rate of cholesterol production.
Liver requires HMG-CoA reductase to
produce cholesterol.
Contraindications



Drug allergy
Pregnancy
Liver disease or elevation of liver enzymes.
Adverse Effects

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

Mild transient GI disturbances, rash and
headache.
CNS: headache, dizziness, blurred vision,
fatigue, nightmares, insomnia.
Severe side effect: muscle pain (myopathy)
Elevation of liver enzymes: need to be
monitored about 6-8 weeks after therapy
started and yearly thereafter.
atorvastatis




Lipitor
Most commonly used drug to lower LDL and
raise HDL
Client needs to have liver enzymes drawn
and cholesterol levels drawn 6-8 weeks after
they start the drug therapy.
Call physician if muscle weakness is noted.
Niacin



Niacin or nicotinc acid is another lipid
lowering drug.
Higher doses are needed than available in
OTC vitamins or niacin pills.
Adverse effects: flushing, pruritus (itching)
and gastrointestinal disturbances.
Life Changes

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Diet: limit intake of high fat foods and animal
proteins
Increase intake of omega oil contained in fish
Exercise
Weight control