Indications
Molnupiravir is an antiviral medicine used to treat mild to moderate C0VID-19 (caused by SARS-CoV-2) in adults who are at risk of developing severe illness. It may help people with C0VID-19 stay out of the hospital and feel better. Molvir is also an antiviral medicine, used in the same way for mild to moderate C0VID-19 in adults at risk of severe illness, and it too may help people stay out of the hospital and feel better. Molnupiravir is an emergency use authorized oral therapeutic for the treatment of C0VID-19 in non-hospitalized patients with mild or moderate disease. Asymptomatic or pre-symptomatic infection: people who test positive for SARS-CoV-2 by virologic testing, using a molecular diagnostic (e.g., polymerase chain reaction) or an antigen test, but have no symptoms. Mild illness: people who have any of the various signs and symptoms of COVID-19 (e.g., fever, cough, sore throat, malaise, headache, muscle pain) without shortness of breath, dyspnoea, or abnormal chest imaging. Moderate illness: people who have evidence of lower respiratory disease by clinical assessment or imaging, with oxygen saturation (Sp02) >94% on room air at sea level. Severe illness: people who have a respiratory frequency >30 breaths per minute, Sp02 <94% on room air at sea level, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (Pa02/Fi02) <300 mmHg, or lung infiltrates >50%. Critical illness: people who have respiratory failure, septic shock, and/or multiple organ dysfunction.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Molnupiravir stops a virus from multiplying by causing widespread mutations as the viral RNA is copied by RNA-directed RNA polymerase. The body metabolizes it into a ribonucleoside analog that resembles cytidine, called β-D-N 4-Hydroxycytidine 5′-triphosphate (also known as EIDD-1931 5′-triphosphate or NHC-TP). When the virus replicates, its enzyme builds NHC-TP into the newly made RNA in place of real cytidine.
Molnupiravir can switch between two forms (tautomers). One form mimics cytidine (C) and the other mimics uridine (U). The virus's proofreading exonuclease enzymes, which can replace mutated nucleotides with corrected ones, don't recognize NHC-TP as an error. So when the viral RNA polymerase copies RNA that contains molnupiravir, it reads it as C at times and as U at other times. This causes more mutations in all the downstream copies than the virus can survive, an effect called viral error catastrophe or lethal mutagenesis.
Pregnancy & Breastfeeding
Animal studies with molnupiravir have shown harmful effects on the unborn animal, and the medicine has not been studied in pregnancy. So nobody knows whether it will harm your baby if you take it while pregnant. For this reason, molnupiravir is not recommended in pregnancy. If you are pregnant, think you may be pregnant, or are planning to have a baby, ask your doctor for advice.
If you can become pregnant, use effective birth control while you are taking molnupiravir and for 4 days after the last dose.
If you are breast-feeding or are planning to breastfeed, tell your doctor before you take this medicine. Breast-feeding is not recommended during treatment and for 4 days after the last dose of molnupiravir. This is because it is not known if molnupiravir gets into breast milk and passes to the baby.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.