Pharmacology of conjugated oestrogens

Conjugated equine oestrogens (CEE) as in Premarin have been used for the treatment of climacteric complaints and the prevention of oestrogen deficiency symptoms since the early 1940's. The biological activity of Premarin's different components is described. Our knowledge of the pharmacokinetics of the nine structurally related oestrogen conjugates in CEE is reviewed. Particular attention is paid to the significance of the sulphate moiety. It is possible that the sulphate group is exerting a 'protective' effect against sudden oestrogenic stimulation.