Thyroid Health
An underactive thyroid and an overactive thyroid are treated with different medicines, not different strengths of the same one. All five medicines here are tablets, and which group applies depends on which direction a person’s thyroid function has moved.
Levothroid
25mcg · 50mcg · 75mcg · 100mcg · 112mcg · 125mcg · 200mcg
Formulated to alleviate hormone deficiencies to support baseline metabolic activity and target systemic lethargy.
Neomercazole
5mg · 10mg
Designed to support thyroid hormone suppression to manage hyperthyroid symptoms and alleviate cardiovascular stress.
Key points
- NICE assesses and manages an underactive thyroid separately from an overactive one.
- NIDDK lists TSH, T4, T3 and thyroid antibody tests as the blood tests used to assess thyroid function.
- Hypothyroidism means too little thyroid hormone is produced; hyperthyroidism means too much.
Medicines for an underactive thyroid
Synthroid and Levothroid contain levothyroxine, used for hypothyroidism and to suppress thyroid-stimulating hormone. Cytomel contains liothyronine, a separate thyroid hormone used for hypothyroidism and, in an emergency, for myxoedema coma. The Emirates Drug Establishment lists Synthroid 100 mcg as levothyroxine sodium, the same ingredient sold under other brand names elsewhere.
Medicines for an overactive thyroid
NeoMercazole contains carbimazole and Tapazole contains thiamazole, both used for hyperthyroidism. Both act on the same gland as the tablets above, treating an excess where the others treat a shortfall.
Why a blood test decides which type applies
NIDDK’s Thyroid Tests page describes TSH as the test usually checked first, with T4, T3 and antibody tests used as needed. NICE’s Thyroid disease: assessment and management guidance treats the two directions as separate pathways, since a medicine’s name alone does not show which one applies.
Further reading
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