Answer
Seek prompt medical advice, especially if the heartbeat is fast or irregular. Call 999 if palpitations occur with chest pain, severe breathlessness, fainting or collapse.
Sources for this answer
- NHSNHS · NHS medicine guidance
- Levothyroxine 25micrograms/5ml Oral Solution — 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.