Answer
Yes. Stop it and seek immediate medical advice because this can signal a severe reduction in white blood cells.
Sources for this answer
- NHSNHS · NHS medicine guidance
- Carbimazole 10 mg Tablets(POM) (PL 43461/0076) — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.