Dydrogesterone

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Dydrogesterone
Dydrogesterone.svg
Dydrogesterone ball-and-stick.png
Clinical data
Trade names Duphaston, others
Synonyms Isopregnenone; Dehydroprogesterone; Didrogesteron; 6-Dehydroretroprogesterone; 9β,10α-Pregna-4,6-diene-3,20-dione; NSC-92336[1][2]
AHFS/Drugs.com International Drug Names
Routes of
administration
By mouth
Drug class Progestin; Progestogen
ATC code
Legal status
Legal status
  • In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability 28%[5]
Protein binding ? (probably to albumin)[5][6]
Metabolism Hepatic: AKR1C1, AKR1C3, CYP3A4[3][4]
Metabolites 20α-DHD (exclusively via AKR1C1 and AKRC13)[4]
Biological half-life Parent: 5–7 hours[7]
Metabolite: 14–17 hours[7]
Excretion Urine
Identifiers
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ECHA InfoCard 100.005.280 Edit this at Wikidata
Chemical and physical data
Formula C21H28O2
Molar mass 312.446 g/mol
3D model (JSmol)
Melting point 144 °C (291 °F)
Boiling point 463 °C (865 °F)
Solubility in water Insoluble mg/mL (20 °C)
  (verify)

Dydrogesterone, sold under the brand name Duphaston among others, is a progestin medication which is used for a variety of indications, including threatened or recurrent miscarriage during pregnancy, dysfunctional bleeding, infertility due to luteal insufficiency, dysmenorrhea, endometriosis, secondary amenorrhea, irregular cycles, premenstrual syndrome, and as a component of menopausal hormone therapy.[6] It is taken by mouth.[6]

Side effects of dydrogesterone include menstrual irregularities, headache, nausea, breast tenderness, and others.[8][9] Dydrogesterone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone.[6][10] The drug is an atypical progestogen and does not inhibit ovulation.[6][11] It has weak antimineralocorticoid activity and no other important hormonal activity.[6][10]

Dydrogesterone was developed in the 1950s and introduced for medical use in 1961.[12] It is available widely throughout Europe, including in the United Kingdom, and is also marketed in Australia and elsewhere in the world.[2][12] The drug was previously available in the United States,[12] but it has been discontinued in this country.[13]

Medical uses[edit]

Dydrogesterone has proven effective in a variety of conditions associated with progesterone deficiency,[14] Infertility due to luteal insufficiency[15][16] including threatened miscarriage,[17] habitual or recurrent miscarriage,[18] Menstrual disorders[19] premenstrual syndrome,[20] and endometriosis.[21] Dydrogesterone has also been registered as a component of menopausal hormone therapy[22] to counteract the effects of unopposed estrogen on the endometrium in women with an intact uterus.

Gynecological disorders[edit]

Primary or essential dysmenorrhea is a very common gynecological phenomenon experienced by women during their reproductive years. Clinical studies have shown symptom relief and a reduction in pain with dydrogesterone treatment for dysmenorrhea.[23] Secondary amenorrhea is not a specific disease, but is instead a symptom. Dydrogesterone has been found to adequately induce bleeding within a sufficiently estrogen-primed endometrium. When estradiol levels are found to be low, dydrogesterone treatment is more effective when supplemented with estrogens.[24] Apart from a wide variety of medications in use to reduce heavy menstrual bleeding in patients with ovulatory cycles, oral progestogens like dydrogesterone have been found to be the most commonly prescribed as it has been found to prevent heavy bleeding.[25]

Endometriosis is a chronic disease which can cause severe, progressive, and at times, incapacitating dysmenorrhea, pelvic pain, dyspareunia and infertility. Dydrogesterone relieves pain without inhibiting ovulation, so that patients are able to become pregnant during treatment. Dydrogesterone is particularly suitable in cases where the woman desires to become pregnant and to prevent bleeding problems.[26] Dydrogesterone results in statistically significant reductions in the symptoms pelvic pain, dysmenorrhea and dyspareunia after the first treatment cycle for the treatment of post-laparoscopic endometriosis.[23] The amount and duration of menstrual bleeding is also significantly reduced, and from the end of the third month onwards, bleeding was considered normal in the majority of patients. Improvement of endometriosis was observed in 71% of patients and cure in 21%.

Dydrogesterone has shown reasonable efficacy in relieving a number of premenstrual syndrome symptoms like mood swings & physical symptoms.[20] Cyclic treatment with low-dose (10 mg/day) dydrogesterone has been found to be effective in the treatment of fibrocystic breast changes and associated breast pain.[27]

Infertility and miscarriage[edit]

Oral dydrogesterone is effective drug, well tolerated and accepted among patients and can be considered for routine luteal support. Advantage of dydrogesterone is oral administration, easy to use and better patient compliance which results in high satisfaction score of oral dydrogesterone in luteal support of IVF/ICSI cycles.[28] According to the latest Cochrane review (2015), no evidence showed a difference between synthetic and micronized progesterone for luteal phase support in terms of successful pregnancies. Dydrogesterone is used for luteal support in IVF protocols, for treatment of recurrent pregnancy loss.[29]

Threatened miscarriage is defined as bleeding during the first 20 weeks of pregnancy while the cervix is closed. It is the most common complication in pregnancy, occurring in 20% of all pregnancies. Recurrent abortion is defined as the loss of three or more consecutive pregnancies. Dydrogesterone is associated with approximately two-fold significant reduction in the miscarriage rate as compared to standard care in threatened and recurrent miscarriages with minimal side effects.[18][30]

Menopausal symptoms[edit]

The objective behind menopausal hormone therapy is to actively increase the circulating levels of estrogen to control hot flashes and to prevent the long-term effects of the menopause, such as bone resorption and unfavourable changes in blood lipids. The administration of estradiol halts, or reverses atrophic changes that occur due to the loss of endogenous estradiol during the menopause.[31]

Estrogen promotes endometrial cell growth and in postmenopausal women with an intact uterus, estrogen monotherapy results in continued endometrial development without the physiological secretory changes normally brought on by progesterone. This action is associated with an increased incidence of endometrial hyperplasia and carcinoma. Additional protection with progestogens is therefore important in patients with an intact uterus who receive estrogen therapy. Dydrogesterone counters the proliferative effect of estrogens on the endometrium and ensures the transition to a secretory pattern and cyclical shedding of the endometrium in serial menopausal hormone therapy regimes. Dydrogesterone effectively protects against the ontogenesis of endometrial hyperplasia. Unlike androgenic progestogens, dydrogesterone does not reverse the benefits brought on by estradiol on lipid profiles and carbohydrate metabolism. In a continuous, combined menopausal hormone therapy regimen, dydrogesterone retards the proliferation of the endometrium so that it remains atrophic or inactive.[32]

Available forms[edit]

Dydrogesterone is available in the form of 10 mg oral tablets both alone and in combination with estradiol.[33][34]

Side effects[edit]

The most commonly reported drug related adverse reactions of patients treated with dydrogesterone without estrogen treatment in clinical trials of indications include menstrual irregularities, headaches, migraines, nausea, breast tenderness, bloating, and weight gain.[8][9] The use of progestins, in particular medroxyprogesterone acetate, in treating postmenopausal symptoms have been associated with increased risk of blood clots[35] and breast cancer in a study carried out by the Women's Health Initiative. While the study did not involve dydrogesterone, it is possible, but not certain, that it too increases these risks.[36]

Dydrogesterone has been prescribed and used in over 10 million pregnancies worldwide. There have been no harmful effects exhibited due to the use of dydrogesterone while pregnant. Dydrogesterone is safe to use during pregnancy only when prescribed and indicated by a medical practitioner.[37] Studies have not shown any incidence of decreased fertility due to dydrogesterone at therapeutic dose.[37] The Ames test found no evidence of any potential mutagenic or toxicity properties.[38]

Overdose[edit]

There is not enough clinical data to support overdose in humans. The maximum dose of dydrogesterone administered to humans to date was 360 mg orally and the drug was found to be well-tolerated at this dose. There are no antidotes to overdose and treatment should be based on symptoms.[37] In acute toxicity trials, the LD50 doses in rats were in excess of 4,640 mg/kg orally.[39][40]

Interactions[edit]

In menopausal hormone therapy, dydrogesterone is administered together with an estrogen. Therefore, the interaction between dydrogesterone and estrogens has been assessed, and no clinically significant interaction has been observed.

Pharmacology[edit]

Pharmacodynamics[edit]

Dydrogesterone is a highly selective progestogen, and due to its unique structure, unlike progesterone and many other progestins, binds almost exclusively to the progesterone receptor (PR).[41] The affinity of dydrogesterone for the PR is relatively low at about 16% of that of progesterone.[42][43] However, in vivo, dydrogesterone is much more potent in comparison, with an equivalent dose, in terms of endometrial proliferation, that is 10 to 20 times lower than that of progesterone.[44] This is due to pharmacokinetic differences between the two drugs, namely improved bioavailability and metabolic stability with dydrogesterone as well as additional progestogenic activity of its metabolites.[45] Dydrogesterone binds to and activates both isoforms of the PR, with a similar selectivity ratio between the two receptors as that of progesterone and lower efficacy at the receptors relative to progesterone.[42] The major active metabolite of dydrogesterone, 20α-dihydrodydrogesterone (20α-DHD), has reduced progestogenic potency relative to dydrogesterone.[42]

Due to its activity as a progestogen, dydrogesterone can produce antigonadotropic effects at sufficient doses in animals.[46] However, it does not suppress gonadotropin secretion or inhibit ovulation at typical clinical dosages in humans;[6][47] dosages of dydrogesterone of 5 to 40 mg/day fail to suppress ovulation (as assessed by urinary pregnanediol and laparotomy), and one study found that ovulation persisted even in women treated with a dosage as high as 400 mg/day (assessed by visual inspection of the ovaries).[48] The inability of dydrogesterone to prevent ovulation in humans is in contrast to all other marketed progestogens except trengestone, which is closely related to dydrogesterone structurally.[48][49] In addition, similarly to trengestone but unlike all other progestogens, dydrogesterone does not increase body temperature (i.e., has no hyperthermic effect).[6][49][50] Also, whereas all other assessed progestins are associated with an increased risk of breast cancer when combined with an estrogen in postmenopausal women, neither progesterone nor dydrogesterone are associated with a significantly increased risk.[51][52] Although dydrogesterone has various atypicalities, the endometrial protection it affords is equivalent to that of other progestins like medroxyprogesterone acetate and norethisterone acetate.[10][53]

Dydrogesterone does not bind importantly to the androgen, estrogen, and glucocorticoid receptors.[43][42] As such, it is devoid of androgenic or antiandrogenic, estrogenic or antiestrogenic, and glucocorticoid or antiglucocorticoid activity.[41][6][42] Similarly to progesterone however, dydrogesterone binds to the mineralocorticoid receptor and possesses antimineralocorticoid activity, but only weakly so.[6][42] Unlike progesterone, which forms sedative neurosteroid metabolites, dydrogesterone is not able to be metabolized in a similar way due to structural differences, and for this reason, is non-sedative, similarly to other progestins.[6]

Effects and properties[edit]

When administered orally, dydrogesterone has advantageous pharmacological properties compared to endogenous progesterone:[54] It is orally active at low dosages. It has selective progestogenic properties without any traditional hormonal activity. And the amount absorbed is more predictable than for progesterone, since it is not broken down as easily when passing through the digestive system.

Dydrogesterone is characterized by progestational and PR-mediated antiestrogenic activity.[55] This is demonstrated by its ability to induce a secretory transformation in the endometrium of immature or ovariectomized animals after they have been primed with estrogens (cf. the Clauberg test). The oral progestogenic potency of dydrogesterone is 20 times higher than that of progesterone.[56] The progestational efficacy and potency of dydrogesterone was confirmed by standard test (i.e. delay of menses and induction of withdrawal bleeding). The benefits of estrogen or other target organs are not compromised by dydrogesterone.[57]

At recommended doses, dydrogesterone has no effect on ovulation in healthy women: The biphasic pattern of the basal body temperature is maintained. Normal ovulatory rise in estrogen and pregnanediol. Normal premenstrual biopsy. No modification of vaginal cytology. Cytological evidence of ovulation. And the formation of the corpus luteum has been confirmed by laparotomy. These beneficial results are of particular relevance to the use of dydrogesterone in women who wish to become pregnant.

Unlike many other synthetic progestogens, dydrogesterone is not chemically related to testosterone. Its low affinity for the androgen receptor explains why it has no unwanted androgenic effects even at high doses and after prolonged treatment showed: No virilization (acne, voice changes, hirsutism) of the adult female. No virilizing effects on the genital tract of the female fetus. And no effect on the fertility of the offspring. In addition, dydrogesterone is not converted into estrogen, and has no adverse estrogenic effects on fertility or sexual development.

Pharmacokinetics[edit]

Dydrogesterone and its major metabolite, 20α-DHD, have predictable pharmacokinetics. The single-dose kinetics are linear in the oral dose range of 2.5 to 10 mg. The pharmacokinetics do not change during repeated administration of up to 20 mg dydrogesterone once daily. Dydrogesterone is readily absorbed after oral administration. The absolute bioavailability of dydrogesterone is on average 28%.[58] Tmax values vary between 0.5 and 2.5 hours.[59] Steady state is attained after 3 days of treatment.[37] The levels of 20α-DHD, which is the main active metabolite, are also found to peak about 1.5 hours post-dose.[37] The plasma protein binding of dydrogesterone and 20α-DHD are unknown, but based on the plasma protein binding of other progestins, they are probably bound to albumin and not to sex hormone-binding globulin or corticosteroid-binding globulin.[5][6]

Dydrogesterone is virtually completely metabolized, which occurs in the liver.[60] The primary metabolic pathway is the hydrogenation of the 20-keto group mainly by AKR1C1 and to a lesser extent AKR1C3, resulting in 20α-DHD, which is a potent progestogen similarly to dydrogesterone.[4] After oral administration, it was found that plasma concentrations of 20α-DHD were substantially heightened than those of the primary drug. The ratios of 20α-DHD and dydrogesterone for AUC and Cmax are in the order of 40 and 25, respectively.[42] As such, dydrogesterone appears to be a prodrug of 20α-DHD.[42] All of the metabolites of dydrogesterone retain the 4,6-diene-3-one structure, and are metabolically stable. As such, dydrogesterone does not undergo aromatization, which is consistent with its absence of estrogenic effects.

The mean elimination half-lives of DHD and dydrogesterone vary between 14 to 17 hours and 5 to 7 hours, respectively.[7] Dydrogesterone and its metabolites are excreted predominantly in urine. Total clearance of plasma is at a rate of 6.4 L/min. Within 72 hours, excretion is virtually complete. DHD is preponderantly present in the urine as a conjugate of glucuronic acid. Approximately 85% of the oral dose is successfully egested from the body within 24 hours.

Chemistry[edit]

Dydrogesterone, also known as 6-dehydroretroprogesterone or as 9β,10α-pregna-4,6-diene-3,20-dione, is a synthetic pregnane steroid and a derivative of progesterone and retroprogesterone.[1][2] Retroprogesterone derivatives like dydrogesterone are analogues of progesterone in which the hydrogen atom at the 9th carbon has been switched from the α-position (below the plane) to the β-position (above the plane) and the methyl group at the 10th carbon has been switched from the β-position to the α-position.[49] This results in a "bent" configuration in which the plane of rings A and B is orientated at a 60° angle below the rings C and D.[6] Analogues of dydrogesterone include trengestone (1,6-didehydro-6-chlororetroprogesterone) and Ro 6-3129 (16α-ethylthio-6-dehydroretroprogesterone).[1]

Although its molecular structure is nearly identical to that of natural progesterone, the unique design of dydrogesterone makes it a potent, orally active progestogen.[61] In the dydrogesterone molecule, the hydrogen atom at the 9th carbon is in the β-position and the methyl group at the 10th carbon is in the α-position – a reverse of the progesterone structure, hence the term 'retro' progesterone. Furthermore, it has a second double bond between the 6th carbon and the 7th carbon (the 4,6-dien-3-one configuration). These small differences in chemical structure account for the improved oral activity, metabolic stability, and the lack of estrogenic, androgenic, glucocorticoid, and mineralocorticoid properties of dydrogesterone.[62]

Dydrogesterone is manufactured by treating progesterone with ultraviolet light, leading to a change in the spatial structure. It is produced from the plant steroids, Dioscorea mexicana, a plant of the yam family native to Mexico. Dioscorea contains a sterol called diosgenin. Diosgenin is converted to progesterone.[63][page needed]

History[edit]

Dydrogesterone is a progestin which was first synthesized by Duphar in the 1950s and was first introduced to the market in 1961. It is unique, being the only retrosteroid that is commercially available and its molecular structure is closely related to that of natural progesterone,[64] but it has enhanced oral bioavailability. It is estimated that during the period from 1977 to 2005[65] around 38 million women were treated with dydrogesterone and that fetuses were exposed to dydrogesterone in utero in more than 10 million pregnancies. It has been approved in more than 100 countries worldwide. It is commercially marketed under the brand name Duphaston and manufactured by Abbott after it took over Solvay Pharmaceuticals. Dydrogesterone was first introduced, by Duphar, as Duphaston in the United Kingdom in 1961.[12] Subsequently, it was introduced in the United States as Duphaston and Gynorest in 1962 and 1968, respectively.[12] Duphaston was removed from the United States market in 1979,[66] and Gynorest is also no longer available in the United States.[67]

Society and culture[edit]

Generic names[edit]

Dydrogesterone is the generic name of the drug and its INN, USAN, and BAN.[1][2][12][68] It was also originally known as isopregnenone.[1][2][12][68]

Brand names[edit]

Dydrogesterone is marketed mainly under the brand names Duphaston (alone) and Femoston (in combination with estradiol).[68][2] It also is or has been marketed alone under the brand names Dabroston, Dufaston, Duvaron, Gestatron, Gynorest, Prodel, Retrone, and Terolut and in combination with estradiol under the brand names Climaston, Femaston, and Femphascyl.[68][2][1][12]

Availability[edit]

Dydrogesterone is available widely throughout the world.[68][2] It is marketed in the United Kingdom, Ireland, South Africa, and Australia, but not in the United States, Canada, or New Zealand.[68][2] The drug was previously available in the United States,[12] but has since been discontinued in this country.[13] Dydrogesterone is also available in elsewhere in Europe, as well as in Central and South America, Asia, and North Africa.[68][2]

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