Answer
Yes. This can indicate methaemoglobinaemia, which reduces the blood's ability to carry oxygen and needs urgent assessment, especially with breathlessness or weakness.
Sources for this answer
- Dapsone 100mg Tablets — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.