Lagevrio (Molnupiravir) Contraindications
Lagevrio is absolutely contraindicated in pregnancy, breastfeeding, and children due to severe teratogenic effects and bone/growth plate toxicity demonstrated in animal studies. 1
Absolute Contraindications
Pregnancy and Breastfeeding
- Do not use molnupiravir in pregnant or breastfeeding individuals due to embryo-fetal lethality and teratogenicity observed in animal studies. 1
- Perform a pregnancy test before initiating treatment if pregnancy status is unclear. 1
- Individuals of childbearing potential must use reliable contraception during treatment and for at least 4 days after the last dose. 1
Pediatric Population
- Molnupiravir should not be used in children due to evidence of impact on growth plate thickness and decreased bone formation in animal studies. 1, 2
Critical Precautions (Strong Relative Contraindications)
Men Planning to Conceive
- Men who might father a child should use reliable contraception during treatment and for at least 3 months after the last dose due to potential genotoxic effects on spermatogenesis. 1, 2
- Uncertainty exists regarding consequences to children conceived by fathers receiving or having recently received molnupiravir. 1
Younger Adults Not at High Risk
- Avoid molnupiravir in younger adults not at high risk for severe COVID-19 because the unknown long-term risk of genotoxicity is likely higher in younger patients compared to older patients. 1
- The potential for malignancy based on preclinical data (very low certainty) remains a concern. 1
Clinical Context for Use Restrictions
Risk-Based Limitations
- Molnupiravir should be reserved only for high-risk patients with non-severe COVID-19, as nirmatrelvir/ritonavir and remdesivir represent superior choices due to greater reductions in hospitalization and fewer safety concerns. 1
- For moderate-risk patients, the WHO recommends against molnupiravir because concerns regarding toxicity outweigh benefits. 1, 2
Common Pitfalls to Avoid
- Do not prescribe molnupiravir without first ruling out pregnancy in individuals of childbearing potential. 1
- Do not use in younger, low-risk patients where the theoretical long-term genotoxicity risk outweighs minimal short-term benefit. 1
- Do not prescribe to men actively trying to conceive without counseling about the 3-month contraception requirement. 1