Cardiovascular Pharmacology

• Cardiac drugs are categorized into seven major classes.

Inotropic Drugs

• Adrenergic drugs, also known as sympathomimetic amines, are one type of inotropic drug
• Anticholinergics, including antimuscarinics and cholinergic blockers, constitute another type
• Digitalis glycosides, such as Digoxin, are also included

Anti-adrenergic Drugs

• Alpha1-adrenergic blockers act as antagonists.
• Beta-adrenergic receptor antagonists are also part of this category.

Vasodilator Drugs

• Angiotensin-Converting Enzyme Inhibitors
• Angiotensin II type 1 Receptor Antagonists
• Calcium Channel Blockers
• Direct vasodilators and Organic Nitrates are also included in this category.

Anti-arrhythmic Drugs

• Class I, Class II, Class III, and Class IV anti-arrhythmics
• Other agents include amiodarone, digoxin, and adenosine

Diuretics

• Refer to specific lectures on the pharmacological treatment of the urinary system for details.

Antiplatelets, Anticoagulants, and Thrombolytics

• These drugs affect blood clotting mechanisms

Antilipemic Drugs

• HMG COA Reductase Inhibitors (statins)

HMG-CoA Reductase Inhibitors

• Statins inhibit cholesterol production and are classified as antilipemic drugs
• The cholesterol biosynthesis pathway converts acetic acid into squalene, eventually forming cholesterol
• Early steps involve reducing HMG-CoA to mevalonate via the HMG-CoA reductase enzyme, followed by steps until squalene and cholesterol are produced

Mechanism of Action

• HMG-CoA reductase inhibitors (statins) block the HMG-CoA reductase enzyme, which converts HMG-CoA to mevalonate
• Ultimately, this reduces cholesterol production.

Indications

• Statins treat hypercholesterolemia, reducing the risk of CAD (coronary artery disease), prevents myocardial infarction or strokes
• Examples include Atorvastatin (Lipitor), Simvastatin (Zocor), fluvastatin, lovastatin, pravastatin, and rosuvastatin

Side Effects

• Gastrointestinal symptoms
• Most cholesterol-lowering drugs may damage liver function, increasing alkaline phosphatase (ALP), alanine transaminase (ALT), and bilirubin levels
• Other hepatic effects may include pancreatitis, drug-induced hepatitis, cirrhosis, and easy bleeding
• Lovastatin, rosuvastatin, and simvastatin may elevate the risk of bleeding, especially when taken with warfarin
• Severe but rare side effects include muscle pain, myopathy, and rhabdomyolysis (muscle tissue breakdown)
• Statins can damage muscle cells' gatekeeper proteins, called ryanodine receptors, which regulate calcium release

Nursing Considerations

• Monitor liver function regularly
• Monitor creatine kinase (CK) levels regularly
• Creatine kinase is an enzyme in skeletal muscle, heart muscle, and brain
• When muscle is damaged, CK leaks into the bloodstream
• Elevated CK levels may suggest muscle injury or disease
• Avoid grapefruit, as it can reduce the statin, increasing the risk of side effects

Cholesterol-Lowering Medications

• Different classes of medications have varying common side effects and precautions.
• Statins may cause headache, stomach upset, and muscle pain also Simvastatin should be taken in the evening and antacids should not be taken at the same time as rosuvastatin
• Fibrates may cause stomach pain, shin rash, or abdominal pain
• Cholesterol absorption inhibitors may cause headache, tiredness, abdominal pain, and flatulence
• Bile acid sequestrants often lead to constipation, gas, or bloating.
• PCSK9 inhibitors may cause injection site reactions (redness, pain, bruising), flu-like symptoms, and muscle pain
• RNA-based therapy may cause injection site reactions, bronchitis, and joint pain

Coagulation Disorders

• Many common diseases affect hemostasis
• Characterized by Hyper-coagulability or thrombophilia, where blood clots form more easily
• Thromboembolic disorders include venous or arterial thrombosis and myocardial infarction
• Hypo-coagulable conditions, also known as bleeding disorders, involve abnormal hemostasis and elevated bleeding risk.
• Examples include thrombocytopenia and hemophilia, which are also considered bleeding disorders

Coagulation Modifiers

• These are used to modify coagulation.
• Anticoagulants inhibit clotting factors, including heparin, which naturally prevents clot formation, and warfarin.
• Antiplatelets interfere with platelet action, such as aspirin and clopidogrel.
• Thrombolytics attack and dissolve existing clots, including alteplase and streptokinase

Heparin

• Heparin is a natural liver substance that prevents clot formation
• It combines with antithrombin III, accelerating reactions that prevent thrombosis
• Heparin inhibits thrombin action, blocking fibrinogen conversion to fibrin, and prevents fibrin clot formation
• Low-molecular-weight heparins (LMWHS) achieve similar anticoagulation with a lower bleeding risk
• Examples include Enoxaparin, Nadroparin, Dalteparin, Tinzaparin,

Warfarin

• Warfarin is a drug that inhibits vitamin K epoxide reductase, impairing vitamin K-dependent clotting factors
• It prevents/treats thromboembolism and arterial embolism, especially in patients with atrial fibrillation or prosthetic heart valves
• A side effect includes bleeding

Warfarin Nursing Considerations

• Monitor International Normalized Ratio (INR) to keep therapeutic range.

Warfarin Prevent Bleeding

• Monitor for unusual bleeding and report bleeding
• Bleeding refers to prolonged nosebleeds, blood in urine, dark urine, vomiting blood, and coughing up blood
• Seek medical attention for excessive bleeding or head injuries
• Notify healthcare providers if invasive medical/dental procedures are needed.

Warfarin Handle With Care

• Patients should hold Warfarin 5 days prior procedures
• Take antiplatelet drugs with food to lessen stomach irritation
• Avoid injury and heavy sports activities
• Avoid alcohol, as it increases bleeding risk. The daily alcohol unit limit is three for men and two for women.

Warfarin Missed Dose

• Take missed dose on that same day
• Skip the dose and take the following dose as scheduled
• Do not double the dose and consult a doctor.
• Warfarin crosses the placental barrier, hence should be avoiaded.
• Warfarin causes fetal bleeding and abnormalities
• Warfarain is not safe during pregnancy

Hemostatics for Promotion of Clot Formation

• Aminocaproic Acid (Amicar) and Tranexamic Acid (Transamin) which helps to prevent and stop bleeding.
• Vitamin K also a substance that promote clot formation and stops bleeding
• Fresh frozen plasma (FFP) acts a an unconcentrated source of all clotting.
• Platelet concentrate treat/prevents bleeding and dysfunction

Tranexamic Acid (Transamin)

• It reduces plasmin and plasminogen inhibiting fiber destruction
• It can also bind fibrin with hemostatic effect

Drugs for Anemia

• Vitamin Supplements, such as Cyanocobalamin (Nascobal)
• Iron Salts, such as Ferrous Sulfate.
• Erythropoiesis occurs in the bone marrow, causing the red cells to be produced
• The Erythropoietin Glycoprotein aids in red blood cell production
• Epoetin alfa, also treats anemia