Estrone sulfate (medication)

This article is about estrone sulfate as a medication. For its role as a hormone, see Estrone sulfate.

Estrone sulfate (E1S) is an estrogen medication and naturally occurring steroid hormone.^[1] It is used in menopausal hormone therapy among other indications.^[1][2] As the sodium salt (sodium estrone sulfate), it is the major estrogen component of conjugated estrogens (Premarin) and esterified estrogens (Estratab, Menest).^[1][3] In addition, E1S is used on its own as the piperazine salt estropipate (piperazine estrone sulfate; Ogen).^[1][3] The compound also occurs as a major and important metabolite of estradiol and estrone.^[1] E1S is most commonly taken by mouth, but in the form of Premarin can also be taken by parenteral routes such as transdermal, vaginal, and injection.^[1][2]

Estrone sulfate (medication)

Clinical data
Other names	E1S; Oestrone sulfate; Estrone 3-sulfate; Estra-1,3,5(10)-trien-17-one 3-sulfate
Routes of administration	By mouth, others[1][2][3]
Drug class	Estrogen; Estrogen ester
Pharmacokinetic data
Protein binding	90%, to albumin, and not to SHBGTooltip sex hormone-binding globulin[4]
Metabolism	Desulfation (via STSTooltip steroid sulfatase)[5]
Metabolites	• Estrone[1] • Estradiol[1]
Elimination half-life	12 hours[6]
Identifiers
IUPAC name [(8R,9S,13S,14S)-13-methyl-17-oxo-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthren-3-yl] hydrogen sulfate
CAS Number	481-97-0 Y 438-67-5 (sodium) 7280-37-7 (piperazine)
PubChem CID	3001028
IUPHAR/BPS	4749
DrugBank	DB04574 Y
ChemSpider	2272513 Y
UNII	QTL48N278K
ChEBI	CHEBI:17474 Y
ChEMBL	ChEMBL494753 Y
Chemical and physical data
Formula	C18H22O5S
Molar mass	350.43 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=S(=O)(O)Oc1cc4c(cc1)[C@H]3CC[C@@]2(C(=O)CC[C@H]2[C@@H]3CC4)C
InChI InChI=1S/C18H22O5S/c1-18-9-8-14-13-5-3-12(23-24(20,21)22)10-11(13)2-4-15(14)16(18)6-7-17(18)19/h3,5,10,14-16H,2,4,6-9H2,1H3,(H,20,21,22)/t14-,15-,16+,18+/m1/s1 Y Key:JKKFKPJIXZFSSB-CBZIJGRNSA-N Y
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Medical uses

E1S is used in menopausal hormone therapy among other indications.^[1][2]

Pharmacology

Pharmacodynamics

See also: Pharmacodynamics of estradiol

E1S itself is essentially biologically inactive, with less than 1% of the relative binding affinity of estradiol for the estrogen receptors (ERs), ERα and ERβ.^[7] The compound acts as a prodrug of estrone and more importantly of estradiol, the latter of which is a potent agonist of the ERs.^[1] Hence, E1S is an estrogen.^[1]

Pharmacokinetics

See also: Pharmacokinetics of estradiol

E1S is cleaved by steroid sulfatase (also called estrogen sulfatase) into estrone.^[5] Simultaneously, estrogen sulfotransferases transform estrone back into E1S, which results in an equilibrium between the two steroids in various tissues.^[5] E1S is thought to serve both as a rapidly-acting prodrug of estradiol and also as a long-lasting reservoir of estradiol in the body, which serves to greatly extend the duration of estradiol when used as a medication.^[1][8][9]

When estradiol is administered orally, it is subject to extensive first-pass metabolism (95%) in the intestines and liver.^[10][11] A single administered dose of estradiol is absorbed 15% as estrone, 25% as E1S, 25% as estradiol glucuronide, and 25% as estrone glucuronide.^[10] Formation of estrogen glucuronide conjugates is particularly important with oral estradiol as the percentage of estrogen glucuronide conjugates in circulation is much higher with oral ingestion than with parenteral estradiol.^[10] Estrone glucuronide can be reconverted back into estradiol, and a large circulating pool of estrogen glucuronide and sulfate conjugates serves as a long-lasting reservoir of estradiol that effectively extends its terminal half-life of oral estradiol.^[10][11] To demonstrate the importance of first-pass metabolism and the estrogen conjugate reservoir in the pharmacokinetics of estradiol,^[10] the terminal half-life of oral estradiol is 13 to 20 hours^[12] whereas with intravenous injection its terminal half-life is only about 1 to 2 hours.^[13]

Estrogen sulfates like estrone sulfate are about twice as potent as the corresponding free estrogens in terms of estrogenic effect when given orally to rodents.^[14] This in part led to the introduction of conjugated estrogens (Premarin), which are primarily estrone sulfate, in 1941.^[14]

• v
• t
• e

Relative oral potencies of estrogens

Estrogen	HFTooltip Hot flashes	VETooltip Vaginal epithelium	UCaTooltip Urinary calcium	FSHTooltip Follicle-stimulating hormone	LHTooltip Luteinizing hormone	HDLTooltip High-density lipoprotein-CTooltip Cholesterol	SHBGTooltip Sex hormone-binding globulin	CBGTooltip Corticosteroid-binding globulin	AGTTooltip Angiotensinogen	Liver
Estradiol	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0	1.0
Estrone	?	?	?	0.3	0.3	?	?	?	?	?
Estriol	0.3	0.3	0.1	0.3	0.3	0.2	?	?	?	0.67
Estrone sulfate	?	0.9	0.9	0.8–0.9	0.9	0.5	0.9	0.5–0.7	1.4–1.5	0.56–1.7
Conjugated estrogens	1.2	1.5	2.0	1.1–1.3	1.0	1.5	3.0–3.2	1.3–1.5	5.0	1.3–4.5
Equilin sulfate	?	?	1.0	?	?	6.0	7.5	6.0	7.5	?
Ethinylestradiol	120	150	400	60–150	100	400	500–600	500–600	350	2.9–5.0
Diethylstilbestrol	?	?	?	2.9–3.4	?	?	26–28	25–37	20	5.7–7.5
Sources and footnotes Notes: Values are ratios, with estradiol as standard (i.e., 1.0). Abbreviations: HF = Clinical relief of hot flashes. VE = Increased proliferation of vaginal epithelium. UCa = Decrease in UCaTooltip urinary calcium. FSH = Suppression of FSHTooltip follicle-stimulating hormone levels. LH = Suppression of LHTooltip luteinizing hormone levels. HDL-C, SHBG, CBG, and AGT = Increase in the serum levels of these liver proteins. Liver = Ratio of liver estrogenic effects to general/systemic estrogenic effects (hot flashes/gonadotropins). Sources: See template.

v t e Metabolic pathways of estradiol in humans Estradiol Estrone sulfate Estrone glucuronide 2-Hydroxyestrone Estrone 4-Hydroxyestrone 2-Methoxyestrone 16α-Hydroxyestrone 4-Methoxyestrone 17-Epiestriol Estriol 16-Epiestriol 17β-HSD EST STS UGT1A3 UGT1A9 CYP450 CYP450 COMT CYP450 COMT unidentified 17β-HSD unidentified Description: The metabolic pathways involved in the metabolism of estradiol and other natural estrogens (e.g., estrone, estriol) in humans. In addition to the metabolic transformations shown in the diagram, conjugation (e.g., sulfation and glucuronidation) occurs in the case of estradiol and metabolites of estradiol that have one or more available hydroxyl (–OH) groups. Sources: See template page.

Chemistry

See also: List of estrogens, Estrogen ester, and List of estrogen esters

E1S, also known as estrone 3-sulfate or as estra-1,3,5(10)-trien-17-one 3-sulfate, is a naturally occurring estrane steroid and a derivative of estrone.^[15] It is an estrogen conjugate or ester, and is specifically the C3 sulfate ester of estrone.^[15] Salts of E1S include sodium estrone sulfate and estropipate (piperazine estrone sulfate).^[15][1][3]

The logP of E1S is 1.4.^[16]