Molnupiravir 200 mg Capsules – COVID-19 Antiviral Uses, Dosage, Side Effects & Full Guide

What is Molnupiravir?

Molnupiravir 200 mg Capsules is an oral antiviral medication used for the treatment of mild-to-moderate COVID-19 in adults who are at high risk of developing severe disease, including hospitalization or death. It is not a preventive drug or a cure for COVID-19 but helps reduce the severity and duration of the illness if taken early.

• Strength: 200 mg per capsule
• Brand Name: Lagevrio (by Merck & Ridgeback Biotherapeutics)
• Drug Class: Antiviral (nucleoside analog)
• Route: Oral (by mouth)

Mechanism of Action

Molnupiravir 200 mg Capsules is a prodrug, meaning it is converted into its active form inside the body. It transforms into N-hydroxycytidine (NHC), which is incorporated into the viral RNA during replication.

• This incorporation leads to a high rate of mutations in the viral RNA.
• The mutations cause “error catastrophe”, preventing the virus from replicating effectively.
• It targets the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) enzyme, which is critical for viral genome replication.

Therapeutic Indication

Molnupiravir is indicated for:

• The treatment of mild-to-moderate COVID-19 in adults (18 years and older)
• Patients who have:
  • Tested positive for SARS-CoV-2
  • At least one risk factor for progression to severe disease (e.g., older age, diabetes, obesity, cardiovascular disease, chronic kidney/lung disease, immunocompromised state)
• Must be started within 5 days of symptom onset for maximum effectiveness

Not approved for prevention of COVID-19 or use in patients younger than 18.

Dosage and Administration

• Recommended Dose: 800 mg (four 200 mg capsules)
• Frequency: Twice daily (every 12 hours)
• Duration: 5 days (no more, no less)
• Total capsules per course: 40

Instructions:

• Swallow capsules whole with water.
• Can be taken with or without food.
• Do not open, crush, or chew capsules.

Efficacy

• In clinical trials, Molnupiravir reduced the risk of hospitalization or death by around 30% compared to placebo.
• Most effective when taken early (within 5 days) of symptoms appearing.

Side Effects

Most patients tolerate Molnupiravir well, but some may experience mild side effects:

Common Side Effects:

• Nausea
• Diarrhea
• Dizziness
• Headache

Less Common / Rare:

• Rash
• Vomiting
• Temporary changes in liver enzyme levels

Warnings and Precautions

• Pregnancy: Not recommended due to potential risk of fetal harm.
  • Women of childbearing potential should use reliable contraception during treatment and for 4 days after the last dose.
  • Male patients with partners of childbearing potential should use contraception during and for 3 months after treatment.
• Breastfeeding: Avoid breastfeeding during treatment and for 4 days after the final dose.
• Children and Adolescents: Not authorized for use in patients under 18 due to potential impact on bone and cartilage growth.

Drug Interactions

• No significant drug interactions.
• Does not require co-administration with a booster (like Ritonavir for Paxlovid).
• Does not interact with cytochrome P450 enzymes.

Storage

• Store at room temperature: 20°C to 25°C (68°F to 77°F)
• Keep in original packaging.
• Protect from moisture and direct sunlight.