Molnupiravir

How it works

It is metabolised to a ribonucleoside analogue that is incorporated into viral RNA by the SARS-CoV-2 RNA-dependent RNA polymerase, introducing errors that accumulate and render the virus non-viable.

Prescribing in practice

• It is not recommended in pregnancy and effective contraception is advised during and for a short period after treatment, as animal data raise a concern about harm to the developing fetus.
• It should be started promptly within a defined early window after symptom onset, since benefit depends on early administration.
• It is not authorised for or shown to benefit those requiring hospitalisation for severe COVID-19, nor for pre- or post-exposure prophylaxis.

Monitoring

Routine laboratory monitoring is not generally required for a short course; review pregnancy status and contraception before prescribing.

Counselling the patient

• Start the course as soon as possible after diagnosis and complete the full treatment.
• Use reliable contraception during and shortly after the course and tell your team if you could be pregnant.
• Seek urgent help if your symptoms worsen or you become breathless.

Evidence & guidelines

Use derives from the MOVe-OUT trial in at-risk outpatients and reflects MHRA authorisation and NICE guidance on COVID-19 treatments.