Abstract

L-thyroxine (Eltroxin - Glaxo; and others), liothyronine (Tertroxin - Glaxo; and others), a mixture of l-thyroxine and l-triiodothyronine (Diotroxin - Glaxo) and dried thyroid (Thyroid BP) are all used in the management of hypothyroidism. Large quantities of Thyroid BP are unfortunately still prescribed, probably not all for the treatment of demonstrable hypothyroidism. Unlike the other preparations, it is not a pure substance and needs to be assayed biologically. Chemical assay which is required by the British Pharmacopoeia does not reflect comparable biological activity.