Important: Therapy notes
MHRA alert: Levothyroxine: new prescribing advice for patients who experience symptoms on switching between different levothyroxine products (May 2021) (www.gov.uk).
MHRA alert: Ritonavir-containing products: reports of interaction with levothyroxine leading to reduced thyroxine levels (October 2018) (www.gov.uk).
- If a liquid levothyroxine preparation is required for patients with swallowing difficulties, crush tablets in 10 to 15mL water to make a suspension and take immediately washed down with some more liquid. The generic tablets from Concordia International and Actavis UK Ltd include this advice within their marketing authorisation (SPC). For specific advice for administration via an enteral feeding tube, refer to your pharmacist.
Important: Formulation and dosage details
Formulation:
Tablets 25 micrograms, 50 micrograms, 75 micrograms, 100 micrograms
Dosage:
Initially 50 to 100 micrograms daily, adjusted in steps of 25 to 50 micrograms every 6 to 8 weeks until normal metabolism maintained (usually 100 to 200 micrograms daily). Older people or cardiac disease, initially, 25 to 50 micrograms daily.
Important: Formulation and dosage details
Formulation:
Oral solution 100 micrograms/5mL
Dosage:
Initially 50 to 100 micrograms daily, adjusted in steps of 25 to 50 micrograms every 6 to 8 weeks until normal metabolism maintained (usually 100 to 200 micrograms daily). Older people or cardiac disease, initially, 25 to 50 micrograms daily.