Cardiac Medications! Flashcards
What is the Mechanism of Action of the beta-blocker ‘Metoprolol’?
The mechanism of action of metoprolol involves its ability to selectively block beta-1 adrenergic receptors. Beta-1 adrenergic receptors are primarily located in the heart, specifically in the myocardium (heart muscle cells). By blocking these receptors, metoprolol reduces the effects of adrenaline on the heart. This leads to several beneficial effects: Decreased heart rate, decreased cardiac output, reduced force of contraction.
List four common side effects of metoprolol.
Fatigue and drowsiness: Metoprolol can cause a feeling of tiredness or lethargy, which may be accompanied by drowsiness or a decrease in energy levels.
Low blood pressure (hypotension): Metoprolol lowers blood pressure. In some cases, this can lead to symptoms such as dizziness, lightheadedness, or fainting.
Bradycardia: Metoprolol can slow down the heart rate. This may result in a heart rate that is lower than normal, leading to symptoms like fatigue, dizziness, or shortness of breath.
Gastrointestinal disturbances: Some individuals may experience gastrointestinal side effects while taking metoprolol, including nausea, vomiting, diarrhoea, or stomach discomfort.
Describe at least three things that should be included in patient education for metoprolol?
When educating patients about metoprolol it’s important to explain its
- purpose and benefits (lowering blood pressure and improving heart function).
- dosage and administration instructions, emphasising the importance of consistent daily intake.
- potential side effects like fatigue or dizziness and instructed to contact their healthcare provider if these persist.
Additionally, precautions such as avoiding alcohol and not abruptly stopping the medication should be discussed.
What is metoprolol and what is its medication class?
Metoprolol is a medication commonly used in the management of cardiovascular conditions, such as hypertension (high blood pressure), angina (chest pain), and certain heart rhythm disorders. It belongs to a class of drugs known as beta-blockers.
What is the renin-angiotensin-aldosterone system RAAS?
The renin-angiotensin-aldosterone system (RAAS) is an important hormonal system in our body that helps to regulate blood pressure by increasing it when it’s too low. It also helps to maintain fluid balance by controlling the reabsorption and excretion of sodium and water.
Remember that renin starts the process, angiotensin II has effects on blood vessels and stimulates aldosterone release, and aldosterone acts on the kidneys to regulate sodium and water balance
What are the signs of digoxin toxicity?
Signs of digoxin toxicity may include:
Major sign - Visual disturbances (blurred or yellow-tinted vision)
Nausea, vomiting, and loss of appetite.
Cardiac arrhythmias, including bradycardia or tachycardia.
Confusion or changes in mental status.
Fatigue and weakness.
Gastrointestinal symptoms, like diarrhea.
What factors increase the risk of a patient experiencing digoxin toxicity?
Advanced age
Impaired kidney function
Electrolyte imbalances
Drug interactions
Overdose or incorrect dosage
What is the antidote for life threatening digoxin poisoning?
digoxin immune fab (Digibind or DigiFab). It works by binding to digoxin in the bloodstream, effectively neutralizing its toxic effects.
Digoxin has very narrow therapeutic index and a very long half life. What are the clinical implications of this?
Individualized dosing: Due to the narrow therapeutic index, each patient may require personalized dosage adjustments based on their response and serum digoxin levels.
Increased risk of toxicity: The long half-life means that digoxin can accumulate in the body over time, increasing the risk of toxicity if not carefully monitored and dosed appropriately. Thus close monitoring is crucial: Close monitoring of the patient’s digoxin levels and clinical response is necessary to maintain therapeutic levels without reaching toxic levels.
What nursing responsibilities are involved in administering digoxin?
Nursing responsibilities in administering digoxin include:
Accurate medication administration: 8 rights of medication administration
Patient assessment: Assess vital signs, heart rate, and rhythm before administering digoxin. IMPORTANT APICAL PULSE FOR 1 MINUTE.
Monitor for any signs or symptoms of digoxin toxicity.
Patient education: Educate patients about the importance of taking digoxin as prescribed, potential side effects, and the need for regular monitoring.
Describe the mechanisms of action of cardiac glycosides
Cardiac glycosides, such as digoxin, work by inhibiting the sodium-potassium ATPase pump in cardiac cells. This inhibition leads to an increase in intracellular calcium levels, which improves the force of myocardial contraction. By enhancing cardiac contractility, cardiac glycosides help to improve symptoms in heart failure patients.
Describe the mechanisms of action of Nitrates
Nitrates, such as nitroglycerin, work by dilating the blood vessels, especially the veins. This vasodilation reduces the workload on the heart and decreases myocardial oxygen demand. Nitrates also dilate the coronary arteries, improving blood flow to the heart muscle. They are commonly used in the management of angina.
Describe the mechanisms of action of ACE inhibitors
ACE inhibitors, such as lisinopril, inhibit the action of the angiotensin-converting enzyme (ACE), which is responsible for converting angiotensin I to angiotensin II. By blocking this conversion, ACE inhibitors reduce the production of angiotensin II, a potent vasoconstrictor, and decrease aldosterone release. This results in arterial and venous dilation, reducing blood pressure and afterload, and improving cardiac output. ACE inhibitors are commonly used to treat hypertension and heart failure.
Describe the mechanisms of action of Statins
Statins, such as atorvastatin, work by inhibiting the enzyme HMG-CoA reductase, which is involved in the production of cholesterol in the liver. By blocking this enzyme, statins reduce the synthesis of cholesterol and promote the clearance of low-density lipoprotein (LDL) cholesterol from the blood. This helps to lower total cholesterol and LDL cholesterol levels, which are risk factors for cardiovascular disease.
Describe the mechanisms of action of ß-adrenoreceptor antagonists
β-adrenoreceptor antagonists, such as metoprolol, block the β-adrenergic receptors in the heart and peripheral blood vessels. By doing so, they reduce the effects of adrenaline and noradrenaline on these receptors. This leads to decreased heart rate, decreased force of cardiac contraction, and vasodilation, resulting in reduced blood pressure and workload on the heart. Beta-blockers are commonly used in the management of hypertension, angina, and heart failure.
Describe the mechanisms of action of anticoagulant medications
The general mechanism of action for anticoagulant medications is to interfere with the blood clotting process, thereby preventing or reducing the formation of blood clots. Anticoagulants work by targeting different components of the coagulation cascade, which is a series of complex reactions that ultimately leads to the formation of a blood clot. Thus acting to prolong the time it takes for blood to clot, making it more difficult for clots to form. By preventing or reducing clot formation, anticoagulant medications help to prevent conditions such as deep vein thrombosis, pulmonary embolism, stroke, and other clotting disorders.
Describe the mechanisms of action of antiplatelet medications
The general mechanism of action for anti-platelet medications is to inhibit platelet aggregation and activation, thereby reducing the risk of blood clot formation. Antiplatelet medications achieve this by targeting different pathways involved in platelet activation.
- Aspirin irreversibly inhibits the enzyme cyclooxygenase (COX), reducing the production of thromboxane A2, a potent platelet activator. This inhibits platelet aggregation and decreases the risk of clot formation.
- Clopidogrel, on the other hand, is a P2Y12 receptor antagonist that blocks the activation of platelets induced by adenosine diphosphate (ADP). By inhibiting this activation pathway, clopidogrel reduces platelet aggregation and the risk of clot formation.
Describe the mechanisms of action of the anticoagulants, Heparin and Warfarin
Anticoagulants, such as heparin and warfarin, prevent the formation of blood clots.
- Heparin works by enhancing the activity of antithrombin III, which inhibits several clotting factors in the blood coagulation cascade, particularly thrombin and factor Xa. This inhibitory effect prevents the conversion of fibrinogen to fibrin and the subsequent formation of blood clots.
- Warfarin, on the other hand, interferes with the synthesis of vitamin K-dependent clotting factors in the liver, namely factors II, VII, IX, and X. By inhibiting the production of these clotting factors, warfarin reduces the ability of the blood to clot.
Describe the nursing management involved in the administration and patient education of these medications including ADRs
Nursing management and patient education: Assess patient history, vital signs, and lab values prior to medication administration. Monitor for ADRs and drug interactions. Educate patients on medication purpose, administration, side effects, and adherence. Promptly report concerns to healthcare provider. Regular lab monitoring, like INR for warfarin. Discuss lifestyle modifications for optimal medication effectiveness.
How does an anticoagulant differ from an antiplatelet?
Anticoagulants and antiplatelets are both medications used to prevent the formation of unwanted blood clots, but they work in different ways and target different parts of the clotting process.
Anticoagulants work throughout the bloodstream to interfere with clotting factors and slow down the clotting process, while antiplatelets work specifically on platelets to prevent them from forming clumps and initiating clot formation in the blood vessels.
What is the general mechanism of action for diuretics?
Diuretics work by increasing the excretion of water and electrolytes, primarily through the kidneys. They do so by either inhibiting the reabsorption of sodium and chloride in the renal tubules (thiazide and loop diuretics) or by inhibiting the reabsorption of sodium at the distal tubules and collecting ducts, while promoting the excretion of potassium (potassium-sparing diuretics). By promoting the elimination of excess fluid, diuretics help to reduce blood volume and lower blood pressure. They are commonly used in the management of hypertension, heart failure, and edema.
