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• Drugs affecting the Hematopoietic System are discussed

Major Classes of Cardiac Drugs:

• Inotropic Drugs: Affect the force of muscular contractions

• Adrenergic drugs or Sympathomimetic Amines boost heart contraction

• Anticholinergics (or Antimuscarinics/Cholinergic blockers) decreases heart contraction.

• Digitalis Glycosides (Digoxin) modulate heart contractions.

• Anti-adrenergic Drugs:

• Alpha1-adrenergic Blockers (Antagonists) reduces blood pressure

• Beta-adrenergic receptor antagonists lower heart rate and blood pressure

• Vasodilator Drugs: Dilates blood vessels

• Angiotensin-Converting Enzyme Inhibitors (ACE inhibitors)

• Angiotensin II type 1 Receptor Antagonists (ARBs)

• Calcium Channel Blockers

• Direct vasodilators

• Organic Nitrates

• Anti-arrhythmic Drugs: Regulate heart rhythm

• Class I, II, III, and IV anti-arrhythmics

• Amiodarone

• Digoxin

• Adenosine

• Diuretics: Promotes urination

• Refer to lecture on pharmacological treatment of the urinary system

• Antiplatelets, Anticoagulants, and Thrombolytics: Prevents blood clotting

• Antilipemic drugs: Lowers lipid levels.

• HMG COA Reductase Inhibitors (statins): A type of antilipemic drug

HMG-CoA Reductase Inhibitors (Statins)

• Cholesterol biosynthesis involves conversion of acetic acid to squalene, then cholesterol.
• Early steps involve HMG-CoA reduction to mevalonate by HMG-CoA reductase.
• Statins inhibit HMG-CoA reductase to convert HMG-CoA to mevalonate, which reduces cholesterol production.
• They treat hypercholesterolemia, reduce the risk of CAD, and prevent MI or stroke.
• Examples include Atorvastatin (Lipitor), Simvastatin (Zocor), fluvastatin, lovastatin, pravastatin, and rosuvastatin.
• Most cholesterol-lowering drugs damage liver function, increasing alkaline phosphatase (ALP), alanine transaminase (ALT), and bilirubin levels.
• Other hepatic effects include pancreatitis, drug-induced hepatitis, cirrhosis, and easy bleeding.
• Lovastatin, rosuvastatin, and simvastatin may increase bleeding risk when administered with warfarin.

Side Effects

• Rare, but can be a severe side effect: Muscle pain, myopathy and rhabdomyolysis (muscle tissue breakdown).
• Statins damage muscle cells' gatekeeper proteins called ryanodine receptors, which control calcium release.

Nursing Considerations

• Monitor liver function (LFT) regularly.
• Monitor Creatine kinase (CK) levels regularly, which is an enzyme found in skeletal muscle, heart muscle, and brain.
• Damage to these tissues can cause Creatine Kinase to leak into the bloodstream
• Elevated CK levels may indicate muscle injury or disease.
• Avoid grapefruit, which can reduce the body's ability to break down the statin, increasing the risk of side effects.

Cholesterol-Lowering Medications

• Statins (Atorvastatin, Rosuvastatin, Simvastatin): Common side effects are headache, stomach upset, and muscle pain.
• Do not take antacids at the same time as rosuvastatin.
• Simvastatin should be taken in the evening and avoided during pregnancy or breastfeeding.
• Contact your doctor if you experience unexplained muscle pain or weakness, loss of appetite, nausea, vomiting, dark urine, etc.
• Avoid taking statins with grapefruit juice.
• Fibrates (Fenofibrate, Gemfibrozil): Can cause stomach pain, abdominal pain, and shin rash.
• Fenofibrate: Swallow with water, do not chew.
• Gemfibrozil: Take 30 minutes before a meal.
• Contact your doctor if you experience unexplained muscle pain or weakness, loss of appetite, nausea, vomiting, dark urine, etc.
• Cholesterol absorption inhibitors (Ezetimibe): May cause headache, tiredness, abdominal pain, stomach upset, flatulence, and nausea.
• Contact your doctor immediately if you experience unexplained muscle pain or weakness, loss of appetite, nausea, vomiting, dark urine, etc.
• Bile acid sequestrants (Cholestyramine): May cause constipation, gas, or bloating.
• Do not take the medication in its dry powder form; mix with fluids and is more palatable if mixed with juices.
• Reduce side effects by eating more high-fiber foods and drinking more fluids.
• Take other medications at least 1 hour before or 4 hours after as this may prevent other medications from being absorbed.
• PCSK9 inhibitors (Alirocumab, Evolocumab): May cause injection site reaction and influenza.
• Store in a refrigerator (2-8°C), do not freeze, and protect from light.
• Only for subcutaneous use; do not shake; discard unused portion.
• Small interfering RNA-based therapy (Inclisiran): May cause injection site reaction, bronchitis, and joint pain.
• Intended for administration by a healthcare professional and only for subcutaneous use.

General Precautions for Cholesterol Medications

• If you experience sleepiness, dizziness, or blurred vision, avoid driving or activities requiring mental alertness.
• Avoid alcohol, as it may increase side effects
• If you notice any allergic reactions, consult your doctor.

Coagulation Disorders

• Many common diseases affect hemostasis.
• Hyper-coagulability or thrombophilia increases blood clot formation.
• The increased tendency of blood to thrombose can lead to Thromboembolic disorders, arterial/venous thrombosis, or myocardial infarction (MI).
• Hypo-coagulable conditions (bleeding disorders) involve abnormal hemostasis.
• This leads to an increased bleeding risk due to thrombocytopenia or hemophilia.
• A stroke may be haemorrhagic or ischaemic.

Coagulation Modifiers

• Type of modification = Prevention of clot formation

• Mechanism of drug action = Inhibit clotting factors

• Drug Classification = Anticoagulants

• Heparin is a natural liver substance that prevents clot formation

• Low-molecular-weight Heparins (LMWHS) Examples = Enoxaparin (Clexane, Lovenox), Nadroparin (Fraxiparine), dalteparin, and tinzaparin

  • Direct Thrombin Inhibitors, e.g. Argatroban (Acova)
  • Factor Xa Inhibitors, e.g. Apixaban (Eliquis)
  • Warfarin (Coumadin) is used in many cases.
  • Clopidogrel (Pravix)

• Drug classification = Antiplatelets

• Tranexamic Acid (Transamin): An Antiplasmin agent

• Used to promote clotting where necessary and to prevent blood loss

• Used as treatment for heavy periods or after surgery.

• Aspirin ~ COX-1 inhibitor, inhibits generation of thromboxane A2 (TXA2)

Warfarin

• Inhibits vitamin K epoxide reductase, which inhibits vitamin K-dependent clotting factors.
• Prevents/treats thromboembolism and arterial embolism in patients with atrial fibrillation and prosthetic heart valves.
• Bleeding is a side effect.
• Monitors the International Normalized Ratio (INR) to keep therapeutic range.
• Avoid eating vitamin K-rich foods, e.g., liver, green leafy vegetables, and alcohol.

Warfarin – Nursing Considerations

• Prevent bleeding

• Take antiplatelet drugs alongside food to help reduce irritation to the stomach/gastric bleeding.

• Avoid drinking a lot of alcohol or getting drunk on warfarin due to increased bleeding risk

  • One daily unit limit is roughly 1/2 a pint of beer or just one measure (25ml) of spirit such as vodka.

• Do not self-medicate and always consult a doctor for advice.

• Prevent drug interaction that enhances warfarin effect that easier leads to bleeding

  • E.g., Aspirin-containing products, Acetaminophen (a-SEET-a-MIN-oh-fen) (Tylenol, others) or acetaminophen-containing products. Consult doctors for advice.

• Please seek medical advice, before starting to take any herbal medicines, especially with warfarin

  • E.g., dong quai, ginkgo biloba, ginseng, St. John's wort, glucosamine, green tea extract, and fish oil.

• Report and monitor any unusual bleeding like coughing of blood and reporting dark coloured urine or stools Seek immediate medical attention for bleeding a lot that just doesn't cease, or any head injuries that can lead to internal bleeding problems

Warfarin Dosage

• Dosage may be prescribed differently in Odds & Evens Days for alternating does

• Dosage is standardized using 1mg (brown) and 3mg (light blue)

• To handle missed doses

• If remember on the same day, take the missed dose as soon as you remember and notify relevant authorities like GP

• If remember on the next day, skip the missed dose and resume the next normal regular dosage

• Do not double the dose!!

• DOACs are a new generation of oral anticoagulants

• Helps to prevent the blood from clotting from inside the vessels

DOAC Precautions

• DOACS can never elimante the risk of blood clots/side effects
• Seek medical attention from symptoms such as stroke (sudden severe headache / blurred vision / dizziness / slurred speech)

Drugs Used In Treatment Of Anemia :

• Vitamin Supplements, e.g. Cyanocobalamin (Nascobal) is a manufactured version of vitamin B12., Folic Acid and folate are forms of vitamin B9.
• Iron Salts, e.g. Ferrous Sulfate
• Erythropoietin is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia. It stimulates red blood cell production (erythropoiesis) in the bone marrow.
• Epoetin alfa is a synthetic form of erythropoietin used to treat specific anemias.