Molecular structure pattern

Coronavirus Disease 2019 (COVID-19) Drug Summary

Last updated: 25 September 2026
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Antivirals



Drug Dosage Remarks
Ensitrelvir  Adults and children ≥12 years old:
375 mg PO on day 1 followed by 125 mg PO on day 2-5 

Adverse Reactions

  • Headache, diarrhea, cough

Special Instructions

  • Should be taken as soon as possible and within 72 hours following contact with an individual who has COVID-19
  • Contraindicated in patients with clinically significant hypersensitivity reactions to Ensitrelvir or any other components of the product
  • Avoid co-administration with strong CYP3A inducers as it can significantly reduce plasma concentrations and may be associated with potential for loss of virologic response.
Molnupiravir Adult: 800 mg PO 12 hourly x 5 days Adverse Reactions
  • GI effects (diarrhea, nausea); Other effect (dizziness)
Special Instructions
  • Not to be used >5 consecutive days or as pre- and post-exposure prophylaxis
  • Not recommended in patients <18 years old, lactating during treatment and for 4 days after the final dose
  • Use with caution in women with childbearing potential as it may cause adverse maternal and fetal outcomes including pre-eclampsia, eclampsia, preterm birth, premature membrane rupture, VTE and fetal death
Nirmatrelvir/Ritonavir 300 mg Nirmatrelvir PO with 100 mg Ritonavir PO 12 hourly x 5 days Adverse Reactions
  • GI effects (dysgeusia, diarrhea, abdominal pain, nausea/vomiting); Hypersensitivity effects (anaphylaxis, serious skin reactions [including toxic epidermal necrolysis Stevens-Johnson syndrome]); Hepatic effects (hepatic transaminase elevations, clinical hepatitis, jaundice); Other effects (headache, hypertension, malaise)
Special Instructions
  • Administer within 5 days of symptom onset
  • Not recommended in patients with severe renal impairment (eGFR <30 mL/min), severe hepatic impairment (Child-Pugh Class C)
  • Use with caution in patients with renal and hepatic impairment, pre-existing liver diseases, liver enzyme abnormalities, hepatitis, uncontrolled or undiagnosed HIV-1 infection
  • Co-administration with drugs highly dependent on CYP3A for clearance, drugs for which elevated concentrations are associated with serious and/or life-threatening reactions, and drugs that are strong CYP3A inducers are contraindicated
Remdesivir Patient on ECMO or invasive mechanical ventilation
Neonates ≥ 1.5 kg: 2.5 mg/kg/dose IV once on day 1, followed by 1.25 mg/kg/dose IV 24 hourly x 9 days
Infants ≥28 days old and >3 kg, children and adolescents <18 years old: 5 mg/kg/dose IV once on day 1, followed by 2.5 mg/kg/dose IV 24 hourly x 9 days
Adult: 200 mg IV once on day 1, followed by 100 mg IV 24 hourly x 9 days
Duration of treatment for patients not requiring ECMO or invasive mechanical ventilation is 5 up to 10 days 
 Adverse Reactions
  • Significant effects (increased transaminase levels, infusion-related and anaphylactic reactions including angioedema, diaphoresis, dyspnea, bradycardia or tachycardia, hypotension, nausea/vomiting, rash, shivering, wheezing); Metabolic effect (hyperglycemia); Renal effects (increased serum creatinine, decreased eGFR or CrCl, acute kidney injury); Other effects (anemia, fever, headache)
Special Instructions
  • Use with caution in patients with renal and hepatic impairment
    • Recent US FDA update in July 2023 allows Remdesivir to be used without dose adjustment in patients with an eGFR of <30 mL/min including patients on dialysis
  • Not recommended for term newborns (7-28 days) with serum creatinine levels ≥1 mg/dL; patients with ALT levels ≥5 times the upper limit of normal range
  • Perform LFT and hematology test at baseline and daily during therapy
  • Determine eGFR and serum creatinine prior to initiation and daily during therapy

Disease-Modifying Anti-Rheumatic Drug



Drug Dosage Remarks
Barcitinib 4 mg PO 24 hourly x 14 days

 Adverse Reactions
  • Hepatic effects (increased liver enzymes, creatine phosphokinase); Other effects (thrombocytosis, neutropenia, deep vein thrombosis, pulmonary embolism, urinary tract infection [UTI])
Special Instructions
  • Avoid initiation or discontinue therapy in patients with lymphopenia or neutropenia
  • Monitor patients who may be at risk for GI perforation; evaluate promptly if new onset of abdominal symptoms are seen
  • Monitor for changes in lymphocytes, neutrophils, hemoglobin, liver enzymes and lipids

Immunosuppressant



Drug Dosage Remarks
Tocilizumab Hospitalized patients (≥2 years) and receiving systemic corticosteroids that require supplemental oxygen or mechanical ventilation:
<30 kg: 12 mg/kg 60-minute IV infusion as single dose
 ≥30 kg: 8 mg/kg 60-minute IV infusion as single dose

 Adverse Reactions
  • Hepatic effect (increased transaminase levels); GI effects (constipation, diarrhea, nausea); Renal effect (urinary tract infection); CV effect (hypertension); Neurologic effects (anxiety, insomnia); Other effect (hypokalemia)
Special Instructions
  • For individuals weighing >100 kg, doses exceeding 800 mg per infusion are not recommended
  • ALT/AST should be monitored
  • Serious infections (eg tuberculosis, bacterial, invasive fungal, viral and other opportunistic infections) have occured
    • If a serious infection develops, discontinue therapy until infection is controlled

Vaccines



Drug Dosage Remarks
Vaccine, COVID-19, adjuvant Adults and children ≥ 12 years old: 0.5 mL IM Adverse Reactions
  • Local effects (injection site tenderness, erythema and swelling); Other effects (fatigue, malaise, nausea/vomiting, headache, arthralgia, myalgia, chills, fever)
Special Instructions
  • For individuals previously vaccinated with any COVID-19 vaccine, administer dose at least 2 months after the last dose
  • Not recommended in patients with known history of severe hypersensitivity reaction (eg anaphylaxis) to any of the components of the vaccine
  • Use with caution in individuals receiving anticoagulant therapy or those with thrombocytopenia or any coagulation disorder (eg hemophilia) and are immunocompromised
  • Monitor for myocarditis and pericarditis; avoid strenuous physical activities for 2 weeks after vaccination
  • Postpone vaccination in individuals suffering from acute severe febrile illness or acute infection
Vaccine, COVID-19, mRNA (nucleoside-modified) ≥6 months-23 months: 0.25 mL IM
Without history of COVID-19 mRNA vaccination: First dose followed by second dose after 1 month
Previously received 1 dose of COVID-19 mRNA vaccine: Single dose 1 month after the last dose
Previously received ≥2 doses of COVID-19 mRNA vaccine: Single dose ≥2 months after the last dose
2-11 years old: 0.25 mL IM as single dose (if previously vaccinated with any COVID-19 vaccine, administer ≥2 months after the last dose)
≥12 years old: 0.5 mL as single dose (if previously vaccinated with any COVID-19 vaccine, administer ≥2 months after the last dose)
 Adverse Reactions
  • Local effects (injection site pain, erythema and swelling); Other effects (nausea/vomiting, headache, fatigue, loss of appetite, fever, chills, arthralgia, myalgia, axillary swelling/tenderness)
    • Sleepiness, irritability/crying and groin tenderness/swelling may be observed in younger patients
Special Instructions
  • Not recommended in patients with known history of severe hypersensitivity reaction (eg anaphylaxis) to any of the component of the vaccine
  • Monitor for myocarditis and pericarditis
Adults and children ≥12 years old: 0.5 mL IM as single dose (if previously vaccinated with any COVID-19 vaccine, administer ≥3 months after the last dose) 
Adults and children ≥5 years old: 0.3 mL IM as single dose (if previously vaccinated with any COVID-19 vaccine, administer vaccine ≥2 months after the last dose) 
Vaccine, COVID-19, mRNA (nucleoside-modified)/Influenza  Adults ≥50 years old: 0.32 mL IM 

Adverse Reactions

  • Local effects (injection site tenderness, erythema and swelling); Other effects (nausea and vomiting, fatigue, myalgia, headache, arthralgia, chills, lymphadenopathy, fever)

Special Instructions

  • Contraindicated in patients with known history of severe hypersensitivity reaction (eg anaphylaxis) to any of the components of the vaccine
  • Use with caution in individuals receiving anticoagulant therapy or those with thrombocytopenia or any coagulation disorder (eg hemophilia) and immunocompromised
  • Monitor for myocarditis and pericarditis
  • Postpone vaccination in individuals suffering from acute severe febrile illness or acute infection

Disclaimer

All dosage recommendations are for non-pregnant and non-breastfeeding women and non-elderly adults with normal renal and hepatic function unless otherwise stated. 
Not all products are available or approved for above use in all countries. 
Products listed in the Drug Summary are based on indications stated in the locally approved product monographs. 
Please refer to local product monographs in Related MIMS Drugs for country-specific prescribing information.