COVID-19

Disease Description (Causes and Symptoms)

• Cause: Occurs when SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) binds to ACE2 receptors on respiratory epithelial cells, enters them, and replicates. The initial outbreak is believed to have originated from an animal source.
• Pathophysiology: Viral replication → upper respiratory tract and lung injury and triggering of an inflammatory response. In some patients, an excessive immune response (increased cytokines) and a prothrombotic tendency occur together, causing severe lung injury (ARDS) and systemic dysfunction.
• Main symptoms: Fever, cough, sore throat, sputum, shortness of breath, muscle aches, headache, fatigue, and decreased sense of smell and taste. The incubation period is an average of 2–5 days (up to approximately 14 days).
• Groups at risk of complications: The risk of progression to severe disease increases in older adults and people with underlying cardiovascular, pulmonary, kidney, liver, or immunocompromising conditions, obesity, diabetes, and other underlying diseases.

Treatment Methods

• General principles: For mild disease, symptomatic treatment, isolation, and monitoring; consider early antiviral treatment for high-risk groups; for severe disease, oxygen therapy, anti-inflammatory treatment, anticoagulation, and intensive care.
• Antivirals (effectiveness and indications may vary depending on the time point and variant):
  • Mild disease in a high-risk individual (at risk of progression to severe disease): nirmatrelvir-ritonavir (oral, Paxlovid) — recommended to be administered as soon as possible after symptom onset (generally within 5 days). Extensive drug interactions involving ritonavir must be checked.
  • Intravenous antiviral: remdesivir (conditional; a 3-day regimen in some high-risk outpatients and inpatients) — infusion is required.
  • Alternative: molnupiravir (oral) — limited use when other medications cannot be used (relatively lower efficacy).
  • Monoclonal antibody treatments: Efficacy may decrease depending on the specific variant, so current effectiveness and recommendations may change (check local public health guidelines).
• Anti-inflammatory/immunomodulatory treatment:
  • Patients requiring oxygen therapy: dexamethasone 6 mg/day (or an equivalent dose) is recommended for up to 10 days (evidence of reduced mortality in patients with severe disease).
  • Selective additional treatment: Evaluate the use of tocilizumab (an IL-6 inhibitor) and other treatments in patients with rapid worsening of severe disease and high inflammatory markers.
• Anticoagulation:
  • Standard-dose thromboprophylaxis for inpatients (unless contraindicated). Consider therapeutic anticoagulation in severe disease and specific situations.
• Supportive care:
  • Antipyretics and analgesics, hydration and nutritional support, and oxygen supply for shortness of breath (noninvasive or invasive ventilation, and ECMO if necessary).
• Treatments not recommended:
  • Routine use of unapproved antivirals or antimalarial drugs (e.g., hydroxychloroquine) is not recommended.
• Prevention: Vaccination (primary series and boosters) is the most important measure for preventing severe disease and death.

Checkpoints Before an Outpatient Visit (Including Example Questions)

• Items to prepare (recommended to bring)
  • Date symptoms began (or the date of a positive test)
  • Current symptom list and progression (temperature and whether shortness of breath is present)
  • Oxygen saturation (if possible, records measured at rest and during activity)
  • List of medications currently being taken (including prescription drugs, OTC medications, and herbal products)
  • Underlying diseases and previous test results (such as recent chest imaging and blood tests)
  • Vaccination (COVID-19 vaccination) and history of recent infection
• Information to provide to healthcare professionals during the outpatient visit
  • Date symptoms began, signs of worsening (shortness of breath, chest pain, fainting, or confusion), and recent exposure history
  • CYP3A4-related medications among currently used drugs (possible interactions with ritonavir)
• Symptoms to report immediately (emergency visit recommended)
  • Severe shortness of breath, persistent chest pain or pressure, decreased consciousness or confusion, cyanosis (paleness of the lips or face)
• Example questions (for patients' self-assessment and record-keeping)
  • When did the symptoms begin, and how has the body temperature changed?
  • Is the oxygen saturation below 94% at rest?

Examples of General Questions to Ask a Doctor

• "Can I receive an antiviral medication (e.g., Paxlovid) in my case? What side effects or drug interactions should I be aware of?"
• "What symptoms or signs indicate that hospitalization is needed? When should I go to the emergency room?"
• "Do any of my current medications (e.g., statins, anticoagulants, or antianxiety medications) need to be adjusted because of drug interactions?"
• "What are the criteria for isolation, discharge, and returning to work after recovery?"

Examples of Disease-Specific Questions

• "The [medication name] I am taking interacts with ritonavir. How should it be adjusted if Paxlovid is prescribed?"
• "I have persistent fatigue/memory impairment (or shortness of breath) after COVID-19 infection. Could this be a long-term consequence (Long COVID), and what are the plans for testing and rehabilitation?"

(Note) Because recommendations vary by region and over time, the latest guidelines from the healthcare institution and public health authorities should be checked and applied regarding antiviral indications, isolation criteria, and the use of monoclonal antibodies.