In-Depth Look at Side Effects and Management Strategies for Long-Term Antithrombotic Use

As the number of patients requiring long-term use of life-saving antithrombotic agents increases, accurate understanding and systematic management of potential side effects, such as bleeding risks, become essential. This article provides a detailed analysis of possible side effects from long-term use of different types of antithrombotic agents and suggests practical management strategies for patients and healthcare professionals.

The Necessity of Long-Term Antithrombotic Use and Key Side Effect Patterns

Looking at their role and classification as essential drugs for cardiovascular disease prevention, fatal cerebrovascular and cardiovascular diseases like myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism are caused by thrombus (blood clot) formation. Antithrombotic agents play a crucial role in preventing the recurrence of these diseases and maintaining life by inhibiting thrombus formation. Long-term use is particularly essential for high-risk patients or those with a medical history of these conditions. Antithrombotic agents are broadly categorized based on their mechanism of action into antiplatelet agents (e.g., aspirin, clopidogrel), which prevent platelet aggregation, and anticoagulants (e.g., warfarin, NOACs/DOACs), which inhibit the blood clotting process itself.

The recent trend of increasing long-term antithrombotic use is driven by a combination of factors, including the rise in chronic diseases, an aging population, and improved survival rates due to medical advancements. While this contributes to effective management of cardiovascular and cerebrovascular diseases and enhances patients' quality of life, it also leads to increased reliance on medication and prolonged exposure to potential side effects. Currently, antithrombotics are widely prescribed in Korea for patients with atrial fibrillation, coronary artery disease, and post-stroke management. Following stent procedures, dual antiplatelet therapy (DAPT) is often administered for six months to over a year.

Understanding the bleeding side effects and their characteristics, which are the most critical concerns with long-term antithrombotic use, is important due to the drugs' inherent mechanisms of inhibiting the blood coagulation system or impairing platelet function. This increases the risk of bruising, nosebleeds, gum bleeding, gastrointestinal bleeding, and even cerebral hemorrhage, not only during trauma or surgery but also in daily life. Antiplatelet agents primarily prevent arterial thrombi by inhibiting platelet aggregation, while anticoagulants focus more on preventing venous and intracardiac thrombi. However, both types can increase bleeding risk. Bleeding risk varies significantly depending on the type and dosage of the drug, the patient's underlying conditions (e.g., kidney function, liver function, history of gastric ulcers), and concomitant medications (e.g., NSAIDs). For instance, dual antiplatelet therapy (DAPT) with aspirin and clopidogrel after stent placement carries a higher risk of bleeding than monotherapy.

Examining specific side effects and symptoms by major drug classes, aspirin, an antiplatelet agent, can irritate the gastric mucosa, causing common side effects like gastritis, gastric ulcers, and heartburn, experienced by approximately 10-20% of aspirin users. Clopidogrel or ticagrelor may cause allergic reactions such as dyspnea or urticaria in certain patients. With anticoagulants, the traditional warfarin has numerous interactions with various drugs and foods and requires mandatory monitoring of blood coagulation levels (INR). Newer oral anticoagulants (NOACs/DOACs) are more convenient than warfarin, but dose adjustment is crucial for patients with impaired renal function. NOACs/DOACs require dose adjustments based on kidney function (CrCl); they are often restricted or contraindicated in patients with severe renal insufficiency (CrCl < 30 mL/min). Studies show that NOACs/DOACs tend to have a significantly lower risk of cerebral hemorrhage compared to warfarin, but some agents (e.g., rivaroxaban) have been reported to have a slightly higher risk of gastrointestinal bleeding compared to warfarin.

Other often overlooked side effects of long-term antithrombotic use include non-specific symptoms like edema, dizziness, fatigue, and headaches, in addition to gastrointestinal bleeding. Particularly for NOACs/DOACs, which are excreted via kidney function, regular monitoring of renal function is important for patients with chronic kidney disease or the elderly. Furthermore, research is ongoing into the potential for some drugs to cause decreased bone density or specific types of anemia, although these are rare. It is noted that antiviral drugs like acyclovir can affect liver function but are not directly related to antithrombotics and are therefore excluded from the main scope of this article's analysis.

Systematic Management and Emergency Response for Minimizing Side Effects

The importance of regular medical consultations and check-ups for side effect prevention cannot be overstated. For patients on long-term antithrombotic therapy, consistent communication with their primary physician is paramount. Any unusual symptoms experienced during medication or the onset of a new illness must be reported to the healthcare provider. Regular blood tests are essential to monitor drug efficacy (e.g., INR) and safety indicators (e.g., kidney function, liver function, blood cell counts) and to diagnose the occurrence of side effects early. Patients with impaired kidney function require dose adjustments for NOACs/DOACs, necessitating regular kidney function tests for monitoring.

Strict adherence to lifestyle modifications and medication management guidelines is also crucial. While taking antithrombotics, patients should avoid strenuous exercise or dangerous activities to reduce the risk of bleeding from external trauma. Furthermore, quitting smoking, moderating alcohol intake, and maintaining a healthy diet help promote vascular health and stabilize the drug's effectiveness. For antiplatelet agents like aspirin that can cause gastrointestinal issues, co-prescription of proton pump inhibitors (PPIs) can be effective in reducing the risk of gastrointestinal bleeding. Taking medication immediately after meals may also help minimize irritation to the stomach lining. Before taking any other medications or health supplements, it is imperative to consult with a doctor or pharmacist to check for potential interactions with antithrombotic agents.

Prompt emergency response and seeking medical attention upon detecting signs of bleeding are critical for life preservation. Patients must visit a medical facility immediately if they experience easy bruising, notice their urine turning red or cola-colored, observe black or bright red stools, or experience severe headaches or vision changes. If gastrointestinal bleeding is suspected, symptoms may include black stools or vomiting blood. In cases of suspected cerebral hemorrhage, severe headache, changes in consciousness, or paralysis may accompany neurological symptoms. In such emergencies, rapid diagnosis and appropriate treatment can be life-saving. Relevant academic societies, such as the Korean Society of Cardiology and the Korean Stroke Society, emphasize more careful monitoring for elderly patients, those with renal insufficiency, a history of previous bleeding, or those taking other medications that increase bleeding risk.

In conclusion, while antithrombotic agents are undoubtedly vital medications that save countless lives, the potential for side effects such as bleeding, gastrointestinal problems, and changes in kidney function associated with long-term use must not be overlooked. Patients should acquire accurate information about their medications and work closely with their physicians to minimize risks and maximize therapeutic benefits. Regular consultations and check-ups, maintaining healthy lifestyle habits, and swift action in the event of abnormal signs are essential elements for patients to continue their medication safely and maintain a healthy daily life. This approach goes beyond simply treating illness; it is the path to preserving patients' quality of life and regaining a healthy daily routine.