What are the recommended treatment options for COVID‑19, including antiviral therapy, supportive care, and management for mild and severe disease?

Treatment of COVID-19

For hospitalized COVID-19 patients requiring oxygen or ventilatory support, use corticosteroids (dexamethasone 6 mg daily for 10 days) as the cornerstone of therapy, and consider adding remdesivir and IL-6 receptor antagonists (tocilizumab or sarilumab) if inflammation persists despite steroids. 1, 2, 1

Mild to Moderate COVID-19 (Outpatient Setting)

For symptomatic outpatients within 5 days of symptom onset who are at high risk for progression to severe disease:

First-Line Antiviral Selection Algorithm:

Nirmatrelvir/ritonavir (Paxlovid) is the preferred first-line antiviral 3, 4, 5:

• Provides greatest reduction in hospitalization and mortality
• Critical caveat: Extensive drug-drug interactions require careful medication review before prescribing
• Contraindicated with certain medications (protease inhibitors, some statins, immunosuppressants)

If nirmatrelvir/ritonavir is contraindicated or unavailable:

• Use remdesivir (3-day course) as second choice 4
• Use molnupiravir only when both above options are unsuitable 3, 6
  • Molnupiravir has lower efficacy than nirmatrelvir/ritonavir
  • Should NOT be used in children due to concerns about bone growth plate effects 6
  • Potential long-term safety concerns regarding mutagenesis and carcinogenicity remain uncertain

High-Risk Populations Requiring Treatment:

• Age ≥60 years
• Immunocompromised (including hematological malignancies, transplant recipients)
• Unvaccinated or vaccine non-responders
• Multiple comorbidities (diabetes, obesity, chronic kidney disease, heart disease, COPD)

Treatments NOT Recommended for Outpatients:

• Do NOT use: Hydroxychloroquine 1
• Do NOT use: Ivermectin 3
• Do NOT use: Azithromycin (unless bacterial co-infection documented) 1
• Do NOT use: Corticosteroids in mild disease without hypoxemia 1

Moderate COVID-19 (Requiring Supplemental Oxygen, SpO2 >90%)

7, 2

Treatment algorithm:

1. Dexamethasone 6 mg daily for 10 days (or methylprednisolone 0.5-1 mg/kg/day for 3-7 days) 2

2. Add remdesivir 7, 2

3. If patient is seronegative, consider adding:

   • Monoclonal antibodies (casirivimab/imdevimab) 7
   • High-titre convalescent plasma (only if monoclonal antibodies unavailable) 7

4. If worsening despite dexamethasone with evidence of COVID-19-related inflammation (elevated inflammatory markers, compatible CT findings):

   • Add IL-6 antagonist (tocilizumab or sarilumab) 7, 2
   • OR JAK inhibitor (baricitinib) 7, 2

Severe to Critical COVID-19 (SpO2 <90%, Respiratory Rate >30/min, or Requiring Mechanical Ventilation)

2

Mandatory treatments:

1. Remdesivir 2

2. Dexamethasone 6 mg daily (only if COVID-19-related inflammation present AND no co-infections that would worsen with steroids) 2

3. Consider combination antiviral therapy: Two antivirals OR antiviral + monoclonal antibodies 2

4. If inflammation persists despite steroids, add second immunosuppressant:

   • Tocilizumab or sarilumab (anti-IL-6) 2
   • OR Baricitinib (JAK inhibitor) 2

5. High-titre convalescent plasma may be useful in critical ventilated patients, preferably within first 48 hours of ventilation initiation 2

6. For patients on mechanical ventilation within 48 hours of intubation: Consider vilobelimab (anti-C5a monoclonal antibody) 2

Respiratory Support Strategy:

• High-flow nasal cannula (HFNC) or non-invasive CPAP (helmet or facemask) for hypoxemic respiratory failure without immediate need for intubation 1
• Prone positioning for patients with hypoxic respiratory failure 1
• Anticoagulation is recommended for all hospitalized COVID-19 patients 1

Special Populations

Immunocompromised/Hematological Malignancy Patients 7, 2:

For mild COVID-19:

• Anti-SARS-CoV-2 monoclonal antibodies (preferred)
• Remdesivir
• Nirmatrelvir/ritonavir (monitor drug interactions with chemotherapy)
• Molnupiravir
• Inhaled interferon β-1a

Key consideration: These patients have higher mortality risk and should receive early aggressive treatment. Post-exposure prophylaxis with monoclonal antibodies is recommended for high-risk exposures in unvaccinated or vaccine non-responders.

Patients with Liver Disease 8:

• Monitor liver function tests twice weekly if on potentially hepatotoxic medications
• Screen for HBsAg if systemic corticosteroids or immunosuppressants used ≥7 days
• Start HBV antiviral therapy to prevent reactivation
• Avoid tenofovir with lopinavir/ritonavir due to increased tenofovir concentrations; switch to entecavir temporarily
• Withhold off-label treatments if moderate-to-severe liver injury develops

Critical Pitfalls to Avoid

1. Do NOT delay antiviral therapy - Must start within 5 days of symptom onset for maximal benefit
2. Do NOT use corticosteroids in mild disease without hypoxemia - increases harm without benefit 1
3. Do NOT use lopinavir/ritonavir - proven ineffective 1
4. Do NOT combine hydroxychloroquine with azithromycin 1
5. Do NOT use colchicine in hospitalized patients 1
6. Do NOT use interferon-β in hospitalized patients 1
7. Check drug interactions before prescribing nirmatrelvir/ritonavir - extensive interactions can cause serious adverse events
8. Do NOT use molnupiravir in children or pregnant women due to safety concerns 6

Supportive Care for All Patients

• Adequate hydration and nutrition
• Electrolyte monitoring and correction
• Fever management with antipyretics
• Oxygen supplementation to maintain SpO2 ≥90%
• Thromboprophylaxis with anticoagulation 1
• Monitor for bacterial superinfection