Pharmacology - Perfusion and Clotting Review

Cardiovascular Drugs

Drug Classes, Suffixes, and Examples

Antihypertensives: Beta Blockers

Mechanism of Action (MOA)

• Decreases heart rate (HR).
• Reduces secretion of renin.
• Long-term use causes reduced peripheral vascular resistance (PVR).

Indications

• Hypertension (HTN), Angina, Dysrhythmias, and Myocardial Infarction (MI) - Cardioprotective effects
• Migraine headaches
• Essential tremors and stage fright
• Decreases heart rate, resulting in decreased myocardial oxygen demand and increased oxygen delivery to the heart
• Prophylactic treatment for angina

Contraindications

• Asthma, because it can cause bronchoconstriction
• Systolic Heart Failure (HF)
• Serious conduction disturbances
• Diabetes Mellitus Type II (DM II): Can mask hypoglycemia-induced tachycardia.
• Peripheral Vascular Disease (PVD): May further compromise cerebral or peripheral blood flow.

Adverse Effects

• Bradycardia, hypotension
• Atrioventricular (AV) block
• Hyperglycemia or hypoglycemia
• Hyperlipidemia
• Dizziness, fatigue, depression, lethargy
• Impotence, wheezing, dyspnea

Nursing Considerations

• Clients should monitor their pulse rates daily and report a rate below 60 beats/min or symptoms of bradycardia.
• Hold medication if systolic BP is less than 100 mm Hg.
• Instruct patients to report dizziness or fainting.
• Inform patients that these medications should never be abruptly discontinued.
• Inform patients that these medications are for long-term prevention of angina, not for immediate relief.

Calcium Channel Blockers

Mechanism of Action (MOA)

• Cause smooth muscle relaxation by blocking the binding of calcium, preventing muscle contraction.
• Causes coronary artery vasodilation.
• Reduces the workload of the heart.
• Decreases blood pressure (BP).

Indications

• Hypertension (HTN) - Amlodipine.
• Angina
• Dysrhythmias
• Migraine headaches
• Raynaud’s disease
• Decreases heart rate, resulting in decreased myocardial oxygen demand and increased oxygen delivery to the heart

Contraindications

• Known drug allergy
• Acute MI
• Second- or third-degree AV block (unless the patient has a pacemaker)
• Hypotension

Adverse Effects

• Hypotension
• Palpitations
• Tachycardia or bradycardia
• Constipation, nausea, dyspnea

Nursing Considerations

• Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fiber foods.
• Avoid hot tubs and jacuzzis because this causes hypotensive effects.
• Hold dose if systolic BP is less than 100.

ACE Inhibitors

Mechanism of Action (MOA)

• Interferes with the renin-angiotensin-aldosterone system (RAAS).
• Induces aldosterone secretion by the adrenal glands.

Indications

• Hypertension (HTN)
• Heart Failure (HF)
• Renal protective effects in DM
• Decreases heart rate, resulting in decreased myocardial oxygen demand and increased oxygen delivery to the heart

Contraindications

• Systolic Heart Failure (HF)
• Serious conduction disturbances
• Asthma patients because any level of blockade can cause bronchoconstriction.
• Diabetes Mellitus Type II (DM II): Can mask hypoglycemia-induced tachycardia.
• Peripheral Vascular Disease (PVD): May further compromise cerebral or peripheral blood flow.

Adverse Effects

• Angioedema - wheezing, stridor, dyspnea
  • Assess the airway
  • Call emergency response team
  • Apply high-flow O_2
  • Initiate IV access if not in place already
  • Administer epinephrine if anaphylaxis is the cause
  • Administer IV antihistamines
• Hyperkalemia
• Dry non-productive cough
• Fatigue, Dizziness, headache, Mood changes, Impaired taste.

ARBs - Angiotensin II Receptor Blockers

Mechanism of Action (MOA)

• Blocks the binding of angiotensin II to the type 1 receptors.
• Blocks vasoconstriction and the secretion of aldosterone.

Indications

• Hypertension (HTN)
• Heart failure

Contraindications

• Renal or hepatic dysfunction
• Breastfeeding or pregnancy

Adverse Effects

• Chest pain, fatigue, hypoglycemia, diarrhea, UTI, anemia, weakness, hyperkalemia.

Nursing Considerations

• Monitor for hypotension
• DO not use with ibuprofen because it enhances hypotension

Nitrates/Nitrites

Mechanism of Action (MOA)

• Causes vasodilation.
• Relaxes smooth muscle to help with dilation of the coronary arteries.

Indications

• Angina
• Treatment of HF
• Acute MI
• Hypertensive emergencies

Contraindications

• Known drug allergy
• Severe anemia
• Closed-angle glaucoma
• Hypotension
• Severe head injury
• Use of the erectile dysfunction drugs sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra)

Adverse Effects

• Headaches - Expected, usually diminish in intensity and frequency with continued use
• Reflex tachycardia
• Postural hypotension
• Skin irritation with topical application

Nursing Considerations

• Instruct patients never to chew or swallow the sublingual form.
• Instruct patients to keep a fresh supply of sublingual medication on hand; potency is lost in about 3 months after the bottle has been opened.
• To preserve potency, medications should be stored in an airtight, dark glass bottle with a metal cap and no cotton filler.
• Instruct patients in the proper application of nitrate topical ointments and transdermal forms, including site rotation and removal of old medication.
• To reduce tolerance, the patient may be instructed to remove topical forms at bedtime and apply new doses in the morning, allowing for a nitrate-free period.
• Transdermal patches can be applied for 12-14 hours and then take a break while sleeping!!
• During acute angina event!
  • Stop activity and sit or lie down and take a sublingual tablet.
  • If there is no relief in 5 minutes, call 911 or emergency services immediately and take a second sublingual tablet.
  • If there is no relief in 5 minutes, take a third sublingual tablet.

Vasodilators - Diazoxide, Hydralazine, Monoxidil, Nitroprusside

Mechanism of Action (MOA)

• Relax arteriolar or venous smooth muscle and decreases SVR, afterload, and peripheral vasodilation.

Indications

• Hypertension

Contraindications

• Allergy
• Hypotension
• Cerebral edema, head injury
• Acute MI or CAD
• Nitroprusside BLACK BOX WARNING - hypotension and cyanide toxicity

Adverse Effects

• Hydralazine: dizziness, headache, anxiety, tachycardia, edema, dyspnea, nausea, vomiting, diarrhea, hepatitis, systemic lupus erythematosus, vitamin B_6 deficiency, and rash
• Minoxidil: T-wave electrocardiographic changes, pericardial effusion or tamponade, angina, breast tenderness, rash, and thrombocytopenia
• Sodium nitroprusside: bradycardia, decreased platelet aggregation, rash, hypothyroidism, hypotension, methemoglobinemia, and (rarely) cyanide toxicity

Nursing Considerations

• Monitor for Hypotension

Digoxin

Mechanism of Action

• Control ventricular response to atrial fibrillation

Indications

• Heart Failure

Contraindications

• Hypersensitivity
• Ventricular tachycardia
• Atrial fibrillation

Adverse Effects

• Cardiovascular: dysrhythmias, including bradycardia or tachycardia
• Central nervous system: headaches, fatigue, malaise, confusion, convulsions
• Eyes: colored vision (seeing green, yellow, purple), halo vision, flickering lights
• Gastrointestinal: anorexia, nausea, vomiting, diarrhea
• Digoxin Toxicity: Visual disturbances, N, V, anorexia, abdominal discomfort, fatigue.

Nursing Considerations

• Digoxin has a very narrow therapeutic window
• Drug levels must be monitored - Therapeutic level = 0.5-2 mg/mL
• Low Potassium levels increase the risk for digoxin toxicity - Electrolytes must be closely monitored
• Monitor for S/S of digoxin toxicity; if present, hold medication and report findings to the provider.
• Antidote: Digoxin Immune Fab(Digibind)

Amiodarone

Mechanism of Action

• Control ventricular response to atrial fibrillation

Indications

• Dysrhythmias - Supraventricular and ventricular

Contraindications

• Hypersensitivity, iodine allergy
• Severe sinus bradycardia; second- or third-degree heart block
• Warfarin and Digoxin: Digoxin levels increase by 50% and INR increases by 50%

Adverse Effects

• Corneal microdeposits: Halos, photophobia, dry eyes - Most common adverse effect!
• Hypothyroidism/Hyperthyroidism
• Dysrhythmias
• Hepatotoxicity
• Pulmonary toxicity

Nursing Considerations

• Monitor for S/S of hypo/hyperthyroidism
• Monitor for dysrhythmias
• Monitor AST/ALT levels - Hepatic function
• Avoid grapefruit juice
• Obtain baseline ECG
• Amiodarone has a BLACK BOX WARNING

Coagulation Modifier Drugs: Heparin

Mechanism of Action (MOA)

• Inhibit clotting factors Thrombin and Xa

Indications

• Prevention of blood clots

Contraindications

• Hypersensitivity
• Uncontrolled bleeding
• HIT
• Severe thrombocytopenia or open wounds

Adverse Effects

• Alopecia, rash, urticaria
• Bleeding
• HIT

Nursing Considerations

• Do not give subcutaneous doses within 2 inches of: umbilicus, abdominal incisions, open wounds, scars, drainage tubes, or stomas
• Do not aspirate subcutaneous injections or massage the injection site - Hematoma formation
• IV doses are double-checked with another nurse.
• Subcutaneous doses should be given in areas of deep subcutaneous fat and sites rotated.
• DVT prophylaxis: 5000 units subcutaneously 2-3x/day; does not need to be monitored
• Monitor aPTT - every 6 hrs until therapeutic effect is evaluated
• aPTT= ABOUT 60 secs.
• aPTT= 1.5-2
• Antidote: Protamine sulfate

Warfarin

Mechanism of Action (MOA)

• Inhibits production of vitamin K-dependent clotting factors II, VII, IX, and X, which are synthesized in the liver

Indications

• Prevents blood clot formation

Contraindications

• Hypersensitivity
• Uncontrolled bleeding or open wounds
• Uncontrolled HTN
• Pregnancy

Adverse Effects

• Dermal necrosis, bleeding, fever

Nursing Considerations

• Avoid alcohol, NSAIDs, and aspirin
• Use electric razors
• It can be started while the client is on heparin until PT/INR levels indicate adequate anticoagulation - Therapeutic effect takes several days
• Monitor PT/INR regularly - INR without warfarin = 1, with warfarin = 2-3.5
• Avoid vitamin K products: Leafy green vegetables, strawberries, raisins, cantaloupe, potatoes
• Interactions: Amiodarone, fluconazole, erythromycin, metronidazole, sulfonylureas
• Amiodarone + warfarin = Warfarin dose decreased in ½
• Avoid supplements: garlic, gingko, St. John’s wort
• Antidote: Vitamin K

Factor Xa Drugs - Rivaroxaban

Indications

• Prevention of stroke
• Treatment of DVT and PE

Contraindications

• Hypersensitivity
• Severe renal impairment
• Active bleeding

Adverse Effects

• Peripheral edema
• Dizziness, headache, diarrhea
• Hematuria, bleeding, bruising

Nursing Considerations

• Assess for signs of bleeding and hemorrhage
• Bleeding from surgical sites
• No routine labs are required - May falsely elevate INR
• Cannot be given with another anticoagulant

Direct Thrombin Inhibitor - Dabigatran

Indications

• Prevention of stroke and thrombosis

Contraindications

• Hypersensitivity
• Active bleeding
• Pregnancy

Adverse Effects

• Hypersensitivity reaction
• Bleeding; increased GI bleeding

Nursing Considerations

• Monitor renal function - Dose is adjusted according to these levels
• No coagulation monitoring is required
• Interactions: phenytoin, rifampin, St. John’s Wort
• Antidote: Idarucizumab (Praxbind)

Antiplatelets - Clopidogrel

Mechanism of Action (MOA)

• Inhibits platelet aggregation by irreversibly inhibiting the binding of ATP to platelet receptors

Indications

• Decreases risk of MI and stroke

Contraindications

• Hypersensitivity
• Bleeding
• Concurrent use with omeprazole
• Lactation

Adverse Effects

• Steven-Johnson Syndrome
• GI bleeding, neutropenia, thrombocytopenia, leukemia
• GI ulcers
• Vitamin K deficiency
• Flu-like symptoms

Nursing Considerations

• Monitor for S/S of thrombocytopenia, hemolytic anemia, purpura
• Monitor bleeding time drug therapy or prolonged bleeding time
• Monitor CBC with differential and platelet count
• Stop medication 5 days before surgery
• Decreased effect: Amiodarone, Calcium-channel blockers, NSAIDs, PPI

Thrombolytics - Alteplase

Mechanism of Action (MOA)

• Converts plasminogen to plasmin, which breaks down or lyses the thrombus. Clot buster

Indication

• Clot buster

Contraindications

• Hypersensitivity
• Active internal bleeding
• CVA or aneurysm

Adverse Effects

• Intracranial hemorrhage
• GU tract or GI bleeding
• Anaphylaxis
• N,V, Hypotension

Nursing Considerations

• Monitor for bleeding gums, mucous membranes, or injection sites.

Antiplatelet - Aspirin

Indications

• Thrombotic stroke prevention

Contraindications

• Children and teenagers with flu-like symptoms - Reye’s syndrome (swelling of the brain or liver)
• Concurrent use with gingko - Increases bleeding
• PUD

Nursing Considerations

• Assess for bleeding, ulcers
• Administer with food to decrease gastric irritation

Antilipemic Drugs - HMG-CoA Reductase Inhibitors

Mechanism of Action (MOA)

• Decreases production of LDL, increases production of HDL

Indications

• Hypercholesterolemia, prevention of CAD

Adverse Effects

• Hepatotoxicity
• GI upset
• Muscle pain
• Rhabdomyolysis

Nursing Considerations

• Administer with evening meal
• Monitor liver function and CK levels
• Avoid alcohol
• Avoid grapefruit juice

Diuretic Drugs - Furosemide

Indications

• Pulmonary edema
• Edema associated with HF
• Liver disease - Ascites
• Nephrotic syndrome
• HTN

Contraindications

• Allergy/ Allergy to sulfonamide antibiotics
• Hepatic coma
• Severe electrolyte loss

Adverse effects

• Dizziness, headache, N,V,D
• Tinnitus
• Agranulocytosis - Neutropenia, thrombocytopenia
• Hypokalemia, hyperglycemia, hyperuricemia

Nursing Considerations

• It increases serum levels of uric acid and glucose
• Additive effect to aminoglycosides and vancomycin - Ototoxicity and neurotoxicity
• Use with corticosteroids causes hypokalemia
• Increases risk of digoxin toxicity
• Can increase risk of lithium toxicity
• NSAIDs - Decrease diuretic action
• Antidiabetic drugs - Decreases diuretic action

Hydrochlorothiazide

Indications

• Treatment of edema, DI, HTN

Contraindications

• Allergy
• Hepatic coma
• Anuria
• Severe renal failure

Adverse effects

• Hypokalemia
• Hyponatremia
• Hypercalcemia, hyperlipidemia, hyperglycemia, hyperuricemia

Nursing Considerations

• Monitor for electrolyte imbalances
• Antidiabetic drugs - Enhances hypoglycemia
• Corticosteroids - Hypokalemia
• Digoxin or lithium - Toxicity
• NSAIDs - Decreased diuretic effect

Anemia drugs - Ferrous Sulfate

Indications

• Supplement

Contraindications

• Allergy, hemochromatosis, hemolytic anemia, anemia not associated with iron-deficiency

Adverse Effects

• N,V, D, constipation, stomach cramps or pain.

Nursing considerations

• Use straw to avoid teeth discoloration
• Drink plenty of fluids on an empty stomach
• Avoid antacids or milk
• Drink with vitamin C to enhance absorption
• Take between meals
• Patient remains upright or sitting up for 30 min. after taking iron
• Stool color changes to brown/tarry color - Increase fluid intake