From the Guidelines
Molnupiravir is contraindicated in children, pregnant or breastfeeding women, and individuals who may become pregnant during treatment due to potential fetal harm and genotoxic effects. The use of molnupiravir in younger adults not at high risk should also be avoided due to the unknown long-term risk of genotoxicity 1. Key contraindications and precautions include:
- Children: due to evidence of impact on growth plate thickness and decreased bone formation in animal studies
- Pregnancy, breastfeeding, and conception: due to embryo-fetal lethality and teratogenicity in offspring when given to pregnant animals
- Men planning to conceive: should be oriented on the potential for temporary genotoxic effect on sperm cell production and use reliable contraception during treatment and for at least three months after the last dose of molnupiravir
- Younger adults: use should be avoided in those not at high risk due to the unknown long-term risk of genotoxicity It is essential to counsel patients on the potential risks and benefits of molnupiravir treatment, particularly in relation to pregnancy and conception, and to implement strategies to mitigate potential harm at the population level, such as active sequence monitoring of SARS-CoV-2 and pharmacovigilance programmes 1.
From the Research
Molnupiravir Contraindications and Medications to Avoid
- There are no direct contraindications or medications to avoid listed in the provided studies for molnupiravir 2, 3, 4, 5, 6.
- However, the studies suggest that molnupiravir may have a stronger mutagenic effect compared to nirmatrelvir, which could have implications for antiviral resistance development 6.
- The studies also compare the effectiveness of molnupiravir with other antiviral treatments, such as nirmatrelvir-ritonavir, and suggest that nirmatrelvir-ritonavir may be more effective in reducing the risk of all-cause mortality in both non-hospitalized and hospitalized patients 5.
- Molnupiravir was generally well tolerated in the studies, with similar numbers of adverse events across all groups 2, 4.
- The studies do not provide a comprehensive list of medications to avoid when taking molnupiravir, but they do suggest that combination therapy with other antiviral treatments may be useful in mitigating antiviral resistance risk 6.
Potential Interactions and Precautions
- The studies suggest that molnupiravir may be used in combination with other antiviral treatments, such as nirmatrelvir, to increase viral clearance and reduce the probability of viral persistence and rapid intra-host evolution of SARS-CoV-2 6.
- However, the studies do not provide information on potential interactions between molnupiravir and other medications, such as cyclophosphosphate, which was used to immunosuppress mice in one of the studies 6.
- Patients taking molnupiravir should be monitored for adverse events and potential interactions with other medications, and healthcare providers should consider the potential risks and benefits of combination therapy 3, 5.