MHRA
Medicines and Healthcare Regulatory Agency
Market Towers
1 Nine Elms Lane, London SW8 5NQ

29 June 2004

Dear Ms Turner,

Armour Thyroid and Porcine Thyroid Extract for Thyroid replacement Therapy

I am responsible for the professional aspects of the importation of unlicensed medicine and would like to clarify the situation with respect to the above products, as requested.

As you know, synthetic levothyroxine T4 and Liothyronine T3 are available in the UK as licensed medicinal products. “Natural” desiccated thyroid hormone, which contains both T4 and T3, is extracted from the thyroid glands of pigs, and is marketed in the USA under a number of brands. Some of these brands are marketed under US law as food supplements and as such are not authorised by the Food and Drugs Administration (FDA). These products can vary considerably in the content of thyroid hormones, because they are not standardised, and as a result could potentially be dangerous. However, other brands are authorised by the FDA as medicines, and are standardised to the specification of the United States Pharmacopoeia.

The specification of the USP for the content of T4 (85 to 115% of labelled strength) and T3 (90 to 110%) in natural thyroid tablets are similar to the specifications for the content in the individual synthetic hormones (90 to 110% T4, 90 to 110% T3). Thyroid tablets USP contain approximately 38 micrograms of T4 and 9 micrograms of T3 per 65 milligrams of desiccated thyroid, and are available in a wide variety of strengths.

UK and European law recognises that there may be circumstances when licensed products may not be suitable for some patients. The regulations on medicines allow doctors to prescribe an unlicensed medicine for a patient to meet such a special clinical need, on their own direct personal responsibility. Where these unlicensed medicines are not available in the UK they can be imported by appropriately licensed medicines wholesalers, for supply to a doctor or pharmacy, to meet these needs. The importer is required to notify the MHRA in advance of every occasion that they wish to import such a product.

The MHRA can object to importation of an unlicensed medicine if there are concerns about the safety or quality of the product. The MHRA cannot object to importation of an unlicensed medicine solely on the grounds of efficacy. In the case of these thyroid preparations, the MHRA has not objected to their importation provided that they are authorised prescription only medicines, standardised to the USP, and that they are for the treatment of patients with thyroid diseases, for whom the UK licensed synthetic thyroid hormones are not suitable.

We have not told importers that they must provide evidence from prescribers, as this is a matter of clinical judgement. Consequently, these products can be made available to those people who need them, subject to them being prescribed by a doctor.

I hope that this answers your concerns. If you have any further questions, please do not hesitate to contact me.

Graham Matthews
Pharmaceutical Advisor
Defective Medicines Report Centre
Inspection and Enforcement Division

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