MedCompanion

COVID-19

Respiratory / Viral

Source: IDMP View on spectrum chart →
Patient + scenario modifiers
Patient
Clinical scenario / source

Annotations only — chart still shows the full chemistry of each drug.

1. Clinical Syndrome

Acute respiratory illness caused by SARS-CoV-2 (Coronaviridae). Spectrum from asymptomatic infection to severe ARDS + multi-organ failure. Variant landscape changes seasonally (Omicron sub-lineages dominant since 2022; updated boosters track current variants).

Severity tiers (NIH / IDSA):

  • Mild — symptomatic without dyspnea / hypoxia; outpatient.
  • Moderate — clinical or imaging evidence of lower respiratory tract involvement; SpO2 ≥94%.
  • Severe — SpO2 <94%, PaO2/FiO2 <300, RR >30, lung infiltrates >50% — hospitalized + supplemental O2.
  • Critical — respiratory failure, septic shock, multi-organ dysfunction — ICU.

Excludes: post-acute sequelae ("long COVID") — supportive care, separate workflow; multi-system inflammatory syndrome in children (MIS-C) and adults (MIS-A) — IVIG + steroids ± anakinra; SARS-CoV-2 variant pandemic preparedness — separate.

2. Pathogens

Consider the patient: Vaccination status (unvaccinated + booster-stale = higher risk), age (≥65 → highest risk), immunocompromise (transplant, hematologic malignancy, advanced HIV, biologics, chronic high-dose steroids), comorbidities (diabetes, obesity, CKD, COPD, heart disease).

Consider the case: Severity tier drives drug + supportive care. Days from symptom onset for antiviral eligibility (Paxlovid + remdesivir + molnupiravir all within 5–7 days). Drug interactions for Paxlovid are the routine outpatient challenge.

Common

    • SARS-CoV-2

      Sole cause. Variant tracking updates monthly via CDC + WHO. Treatment recommendations stable across current variants (small-molecule antivirals retain activity).

Less common

3. Empiric Therapy

TierFirst choiceAlternativesDurationComments
Outpatient
  • 300 mg / 100 mg · PO BID × 5 days · PO
  • 200 mg IV × 1 → 100 mg IV daily · × 3 days · IV

    Outpatient infusion when Paxlovid contraindicated (severe drug interactions, eGFR <30, severe hepatic impairment, pregnancy with concerns).

  • 800 mg · PO BID × 5 days · PO

    Salvage outpatient when other two unavailable. Lower efficacy. AVOID in pregnancy (mutagenic mechanism).

5 days (Paxlovid, molnupiravir); 3 days (remdesivir outpatient)**Outpatient high-risk + within 5 days of symptoms.** Drug interaction screen MANDATORY before Paxlovid (pharmacist consult ideal). **Paxlovid rebound** (~10–15%): symptomatic recurrence 2–8 d post-completion — NOT a treatment failure, no retreatment needed.
Admitted to ward
  • 200 mg IV × 1 → 100 mg IV daily · × 5 days (extend to 10 if not improving or on mechanical ventilation) · IV
—5–10 days; longer in critical illness or persistent disease**Hospitalized requiring supplemental O2.** **Add dexamethasone 6 mg PO/IV daily × 10 d** (or until discharge if shorter) — mortality benefit established in RECOVERY trial 2020. Combo (dex + remdesivir) is standard.
Admitted to ICU
  • 200 mg IV × 1 → 100 mg IV daily · × 5–10 days · IV
—5–10 days; tailor to clinical course**Critical / mechanically ventilated.** Continue dexamethasone 6 mg daily × 10 d. **Add tocilizumab 8 mg/kg IV × 1 (max 800 mg)** or **baricitinib 4 mg PO daily × 14 d** for rapid O2 escalation (HFNC → NIV → MV within 24–48 h) or markers of hyperinflammation (CRP, ferritin, D-dimer high). Lung-protective ventilation, prone positioning, ECMO consideration in refractory ARDS. **CAPA workup** if not improving — beta-D-glucan, galactomannan, sputum culture; voriconazole if positive.

Add coverage if:

Aspergillus coverage
  • Critically ill / mechanical ventilation >7 days
  • Worsening O2 despite COVID-directed therapy
  • Positive serum / BAL galactomannan or beta-D-glucan
  • Cavitary infiltrate

Add:

  • 6 mg/kg q12h × 2 doses → 4 mg/kg q12h · — · IV/PO

    **CAPA (COVID-associated pulmonary aspergillosis)** — high mortality. ID + pulm consult.

MRSA coverage
  • Bacterial superinfection clues
  • Necrotizing infiltrate
  • Worsening with new fever after initial improvement

Add:

  • load + AUC-guided · — · IV

    Empiric CAP + MRSA when superinfection suspected.

4. Directed Therapy

Outpatient (high-risk + within 5 days symptoms):

  • Paxlovid 300/100 mg BID × 5 d (preferred unless contraindicated).
  • Remdesivir 200 mg IV × 1 → 100 mg IV × 2 days (if Paxlovid contraindicated).
  • Molnupiravir 800 mg PO BID × 5 d (last-line outpatient).
  • Avoid retreatment for Paxlovid rebound — supportive only.

Hospitalized requiring O2:

  • Remdesivir 200 mg IV × 1 → 100 mg IV daily × 5 d (10 d if not improving or on MV).
  • Dexamethasone 6 mg daily × 10 d — standard add-on.
  • Tocilizumab or baricitinib for rapidly escalating O2 / hyperinflammation.

Hospitalized NOT requiring O2:

  • Dexamethasone NOT recommended (may cause harm).
  • Remdesivir less robust evidence; consider in selected high-risk inpatients.
  • Supportive care, monitor for deterioration.

Bacterial superinfection workup if persistent / new fever, new infiltrate, hemodynamic instability. CAPA workup in critical illness not improving.

Adjunct therapies:

  • Anticoagulation: prophylactic-dose for all hospitalized; consider therapeutic in moderate (NOT severe — INSPIRATION + RAPID + ACTIV-4a). Severe / ICU: prophylactic dose.
  • Awake proning in moderate hypoxia (often helpful, low-risk).
  • Convalescent plasma / monoclonal Ab: NOT recommended (mAbs lost activity against Omicron lineages; convalescent plasma minimal evidence).
  • Vitamin D, zinc, ivermectin, hydroxychloroquine: NOT recommended.

Prevention: updated COVID vaccines annually; high-risk patients consider biannual or as recommended by ACIP. Masking + ventilation during community surges. Pre-exposure mAb prophylaxis (Evusheld) no longer effective; no current PrEP.

5. Monitoring

Resolution: symptom improvement, O2 weaning, lung imaging clearance over weeks. Persistent worsening or biphasic illness → bacterial / fungal superinfection workup.

ICU monitoring: ventilator parameters, prone positioning response, organ dysfunction trajectory, hyperinflammation markers (CRP, ferritin, D-dimer), bacterial cultures.

Long COVID (post-acute sequelae 4–12+ weeks post-acute): heterogeneous; fatigue, dyspnea, dysautonomia, cognitive complaints, POTS. Supportive multidisciplinary care — no specific antiviral evidence.

Toxicity: remdesivir → LFTs, infusion reactions, bradycardia (usually clinically silent); dexamethasone → glucose, BP, mood; tocilizumab → infections + LFTs; Paxlovid → drug interactions + dysgeusia.

Pearls

Outpatient high-risk + ≤5 days symptoms → Paxlovid first (drug interaction check non-negotiable). Hospitalized + O2 → remdesivir + dexamethasone. Rapidly escalating O2 → add tocilizumab or baricitinib. CAPA in critically ill is a documented + lethal complication — voriconazole. No mAbs, ivermectin, HCQ, convalescent plasma. Paxlovid + tacrolimus is a transplant-team-managed minefield — remdesivir is safer. Dexamethasone harms patients NOT requiring O2 — don't give it to outpatients.

References