Molnupiravir 

1. Introduction

Molnupiravir is an antiviral medication used to treat mild to moderate COVID-19 in patients at high risk of severe illness. It works by introducing errors into the viral RNA during replication, inhibiting the SARS-CoV-2 virus’s ability to replicate. Molnupiravir is an oral treatment intended for early intervention to reduce the risk of severe outcomes, such as hospitalisation or death.

2. Indications

  • Treatment of mild to moderate COVID-19 in adults:
    • With positive test results for SARS-CoV-2.
    • At high risk of progression to severe COVID-19, including hospitalisation or death.

3. Dosage

Adults (≥18 years):

  • 800 mg (four 200 mg capsules) taken orally every 12 hours for 5 days.

Children:

  • Not authorised for use in patients under 18 years due to potential effects on bone and cartilage growth.

4. Administration

  • Take orally with or without food.
  • Swallow capsules whole; do not open, crush, or chew.
  • Complete the full 5-day course, even if symptoms improve.

5. Forms Available

  • Capsules: 200 mg

6. Side Effects

6.1 Common Side Effects:

  • Diarrhoea
  • Nausea
  • Dizziness

6.2 Less Common Side Effects:

  • Headache
  • Abdominal pain

6.3 Rare but Serious Side Effects:

  • Hypersensitivity reactions (e.g., rash, swelling of face or throat)

7. Warnings

  • Reproductive Toxicity: Molnupiravir may harm a developing foetus. Avoid use during pregnancy unless no alternatives are available, and the potential benefits outweigh the risks.
  • Contraceptive Use: Both men and women of childbearing potential should use effective contraception during treatment and for:
    • Women: 4 days after the last dose.
    • Men: 3 months after the last dose.
  • Not authorised for use in patients requiring hospitalisation for severe or critical COVID-19, as its benefit has not been established in advanced disease stages.

8. Precautions

  • Use only under the guidance of a healthcare provider.
  • Assess renal and hepatic function before use if clinically indicated, although no dose adjustment is required for renal or hepatic impairment.
  • Do not use as a substitute for vaccination.

9. Interactions

  • No significant drug interactions are currently known.
  • Avoid concurrent use of other investigational antivirals without medical advice.

10. Monitoring Parameters

  • Monitor for symptom progression or new onset of severe COVID-19 symptoms.
  • Watch for side effects, especially gastrointestinal symptoms and hypersensitivity reactions.

11. Use in Children

  • Not authorised for patients under 18 years due to potential effects on bone and cartilage growth.

12. Use in Pregnancy

  • Not recommended during pregnancy due to the risk of foetal harm.
  • Perform a pregnancy test in women of childbearing potential before initiating treatment.

13. Use in Elderly

  • No dose adjustment is necessary for elderly patients. Clinical trials have shown similar safety and efficacy in older adults compared to younger adults.

14. Use in Kidney Disease

  • No dose adjustment is required for patients with mild to moderate renal impairment.
  • Limited data are available for patients with severe renal impairment or end-stage renal disease.

15. Use in Liver Disease

  • No dose adjustment is required for mild to moderate hepatic impairment.
  • Data for severe hepatic impairment are limited; use with caution.

16. Patient Counselling Points

  • Start Molnupiravir as soon as possible after a confirmed COVID-19 diagnosis and within 5 days of symptom onset.
  • Take the capsules as prescribed, completing the full 5-day course even if you feel better.
  • Do not share your medication with others.
  • Avoid pregnancy during treatment and for a specified period after completing the course (4 days for women, 3 months for men).
  • Report any severe or persistent side effects to your healthcare provider immediately.

17. Table of Brand Names, Manufacturer, and Prices in USD

Brand NameManufacturerStrength/Dosage FormPrice (USD)
LagevrioMerck200 mg Capsule$700 (40 capsules)

18. 15 FAQs (Frequently Asked Questions)

1. What is Molnupiravir?
Molnupiravir is an antiviral medication used to treat mild to moderate COVID-19 in high-risk patients.

2. How does Molnupiravir work?
It introduces errors into the viral RNA, preventing the SARS-CoV-2 virus from replicating.

3. When should Molnupiravir be taken?
It should be started as soon as possible after a positive COVID-19 test and within 5 days of symptom onset.

4. What is the usual dose of Molnupiravir?
The standard dose is 800 mg (four 200 mg capsules) every 12 hours for 5 days.

5. Can Molnupiravir be used in children?
No, it is not authorised for use in patients under 18 years.

6. Can Molnupiravir be taken during pregnancy?
It is not recommended due to potential risks to the foetus.

7. Can breastfeeding mothers take Molnupiravir?
Breastfeeding is not recommended during treatment and for 4 days after the last dose.

8. What are the common side effects of Molnupiravir?
Common side effects include diarrhoea, nausea, and dizziness.

9. Can Molnupiravir be taken with other medications?
No significant drug interactions are known, but consult your doctor before combining it with other medications.

10. Is Molnupiravir a substitute for COVID-19 vaccination?
No, it is not a substitute for vaccination.

11. How effective is Molnupiravir?
Clinical trials have shown it reduces the risk of hospitalisation and death in high-risk patients when taken early.

12. What happens if I miss a dose?
Take the missed dose as soon as possible unless it is close to the next dose. Do not double the dose.

13. How should Molnupiravir be stored?
Store at room temperature, away from moisture and light.

14. Can Molnupiravir be used in severe COVID-19?
No, it is not indicated for patients requiring hospitalisation due to severe COVID-19.

15. Do I need a prescription for Molnupiravir?
Yes, it is a prescription-only medication.