Clinical data | |
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Trade names | Prodrox |
Other names | OHPA; 17α-Hydroxyprogesterone acetate; 17α-Acetoxyprogesterone; Acetoxyprogesterone; 17α-Hydroxypregn-4-ene-3,20-dione 17α-acetate; 17α-Acetoxypregn-4-ene-3,20-dione |
Routes of administration | By mouth |
Drug class | Progestogen; Progestin; Progestogen ester |
ATC code | |
Identifiers | |
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CAS Number |
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PubChem CID | |
ChemSpider | |
UNII | |
KEGG | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.005.564 |
Chemical and physical data | |
Formula | C23H32O4 |
Molar mass | 372.505 g·mol−1 |
3D model (JSmol) | |
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Hydroxyprogesterone acetate (OHPA), sold under the brand name Prodox, is an orally active progestin related to hydroxyprogesterone caproate (OHPC) which has been used in clinical and veterinary medicine. [1] [2] [3] [4] [5] [6] [7] [8] It has reportedly also been used in birth control pills. [9]
OHPA is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone.
OHPA was discovered in 1953 and was introduced for medical use in 1956. [10] [11] [12]
OHPA has been used in the treatment of a variety of gynecological disorders, including secondary amenorrhea, functional uterine bleeding, infertility, habitual abortion, dysmenorrhea, and premenstrual syndrome. [3] [13] [14]
OHPA (100 mg) was reportedly marketed in combination with mestranol (80 μg) as a sequential combined birth control pill under the brand name Hormolidin. [9] The preparation was available in the early 1970s. [9] The firm that manufactured it, known as Gador, was based in Argentina. [9]
OHPA is a progestogen and acts as an agonist of the progesterone receptor (PR), both PRA and PRB isoforms (IC50 = 16.8 nM and 12.6 nM, respectively). [15] It has more than 50-fold higher affinity for the PR isoforms than 17α-hydroxyprogesterone, a little less than half the affinity of progesterone, and slightly higher affinity than OHPC. [16] Additional studies have reported on the affinity of OHPA for the PR. [17] [18] [19] [20] [21]
OHPA is of relatively low potency as a progestogen, which may explain its relatively limited use. [22] It is 100-fold less potent than medroxyprogesterone acetate, 400-fold less potent than chlormadinone acetate, and 1,200-fold less potent than cyproterone acetate in animal assays. [22] In terms of producing full progestogenic changes on the endometrium in women, 75 to 100 mg/day oral OHPA is equivalent to 20 mg/day parenteral progesterone, and OHPA is at least twice as potent as oral ethisterone in such regards. [3] It is also reportedly more potent than OHPC. [15] [23] OHPA has been found to be effective as an oral progestogen-only pill at a dosage of 30 mg/day. [24]
Compound | hPR-A | hPR-B | rbPR | rbGR | rbER | |||
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Progesterone | 100 | 100 | 100 | <1 | <1 | |||
17α-Hydroxyprogesterone | 1 | 1 | 3 | 1 | <1 | |||
Hydroxyprogesterone caproate | 26 | 30 | 28 | 4 | <1 | |||
Hydroxyprogesterone acetate | 38 | 46 | 115 | 3 | ? | |||
Notes: Values are percentages (%). Reference ligands (100%) were progesterone for the PR , dexamethasone for the GR , and estradiol for the ER . Sources: See template. |
OHPA has very low but nonetheless significant oral bioavailability and can be taken by mouth. [25] The pharmacokinetics of OHPA have been reviewed. [2]
A single intramuscular injection of 150 to 350 mg OHPA in microcrystalline aqueous suspension has been found to have a duration of action of 9 to 16 days in terms of clinical biological effect in the uterus in women. [26]
Compound | Form | Dose for specific uses (mg) [lower-alpha 3] | DOA [lower-alpha 4] | |||
---|---|---|---|---|---|---|
TFD [lower-alpha 5] | POICD [lower-alpha 6] | CICD [lower-alpha 7] | ||||
Algestone acetophenide | Oil soln. | - | – | 75–150 | 14–32 d | |
Gestonorone caproate | Oil soln. | 25–50 | – | – | 8–13 d | |
Hydroxyprogest. acetate [lower-alpha 8] | Aq. susp. | 350 | – | – | 9–16 d | |
Hydroxyprogest. caproate | Oil soln. | 250–500 [lower-alpha 9] | – | 250–500 | 5–21 d | |
Medroxyprog. acetate | Aq. susp. | 50–100 | 150 | 25 | 14–50+ d | |
Megestrol acetate | Aq. susp. | - | – | 25 | >14 d | |
Norethisterone enanthate | Oil soln. | 100–200 | 200 | 50 | 11–52 d | |
Progesterone | Oil soln. | 200 [lower-alpha 9] | – | – | 2–6 d | |
Aq. soln. | ? | – | – | 1–2 d | ||
Aq. susp. | 50–200 | – | – | 7–14 d | ||
Notes and sources:
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OHPA, also known as 17α-hydroxyprogesterone acetate or as 17α-acetoxypregn-4-ene-3,20-dione, is a synthetic pregnane steroid and a derivative of progesterone. [1] [46] It is the acetate ester of 17α-hydroxyprogesterone, as well as a parent compound of a number of progestins including chlormadinone acetate, cyproterone acetate, medroxyprogesterone acetate, and megestrol acetate. [4] [46]
Chemical syntheses of OHPA have been described. [2]
In 1949, it was discovered that 17α-methylprogesterone had twice the progestogenic activity of progesterone when administered parenterally, [47] and this finding led to renewed interest in 17α-substituted derivatives of progesterone as potential progestins. [12] Along with OHPC, OHPA was synthesized by Karl Junkmann of Schering AG in 1953 and was first reported by him in the medical literature in 1954. [10] [11] [48] [49] [12] OHPC shows very low oral activity [16] and was introduced for use via intramuscular injection by Squibb in 1956 under the brand name Delalutin. [12] Although a substantial prolongation of action occurs when OHPC is formulated in oil, [16] the same was not observed to a significant extent with OHPA, and this is likely why OHPC was chosen by Schering for development over OHPA. [7]
Subsequently, Upjohn unexpectedly discovered that OHPA, unlike OHPC and progesterone, is orally active and shows marked progestogenic activity with oral administration, [25] a finding that had been missed by the Schering researchers (who were primarily interested in the oil solubility of such esters). [7] [12] OHPA was found to possess two to three times the oral activity of 17α-methylprogesterone. [50] Upjohn reported the oral activity of OHPA in the medical literature in 1957 and introduced the drug for medical use as Prodox in 25 mg and 50 mg oral tablet formulations later the same year. [3] [12] [13] OHPA was indicated for the treatment of a variety of gynecological disorders in women. [3] [13] [14] However, it saw relatively little use, which was perhaps due its comparatively low potency relative to a variety of other progestins such as medroxyprogesterone acetate and norethisterone. [22] [14] These progestins were introduced around the same time and hence may have been favored. [22] [14]
In 1960, OHPA was introduced also as Prodox as an oral progestin for veterinary use for the indication of estrus suppression in dogs. [8] [51] However, probably due its high cost and the inconvenience of daily oral administration, the drug was not a market success. [8] It was superseded for this indication by medroxyprogesterone acetate (brand name Promone) in 1963, which could be administered by injection conveniently once every six months, although this preparation was discontinued in 1966 for various reasons and hence was not a market success either. [8]
Hydroxyprogesterone acetate is the generic name of the drug and its INN . [1]
OHPA is or was marketed under the brand name Prodox initially for clinical use and then for veterinary use. [1] Other brand names of OHPA include Gestageno, Gestageno Gador, Kyormon, Lutate-Inj, Prodix, and Prokan. [1] OHPA may also be or have been marketed in combination with estradiol enantate under the brand names Atrimon and Protegin in Argentina and Nicaragua. [52]
OHPA is no longer marketed and hence is no longer available in any country. [53] [54] [52]
A progestogen, also referred to as a progestagen, gestagen, or gestogen, is a type of medication which produces effects similar to those of the natural female sex hormone progesterone in the body. A progestin is a synthetic progestogen. Progestogens are used most commonly in hormonal birth control and menopausal hormone therapy. They can also be used in the treatment of gynecological conditions, to support fertility and pregnancy, to lower sex hormone levels for various purposes, and for other indications. Progestogens are used alone or in combination with estrogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of progestogens include natural or bioidentical progesterone as well as progestins such as medroxyprogesterone acetate and norethisterone.
Gestonorone caproate, also known as gestronol hexanoate or norhydroxyprogesterone caproate and sold under the brand names Depostat and Primostat, is a progestin medication which is used in the treatment of enlarged prostate and cancer of the endometrium. It is given by injection into muscle typically once a week.
Hydroxyprogesterone caproate, sold under the brand name Delalutin among others, is a medication used to reduce the risk of preterm birth in women pregnant with one baby who have a history of spontaneous preterm birth. In March 2023, the manufacturer, Covis Pharma, agreed to withdraw the drug from the US market. The approval of this drug substance was withdrawn by the US Food and Drug Administration (FDA) in April 2023. In May 2024, the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency recommended suspending the marketing authorizations of medications containing 17-hydroxyprogesterone caproate in the European Union.
Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy.
Dimethisterone, formerly sold under the brand names Lutagan and Secrosteron among others, is a progestin medication which was used in birth control pills and in the treatment of gynecological disorders but is now no longer available. It was used both alone and in combination with an estrogen. It is taken by mouth.
Algestone acetophenide, also known more commonly as dihydroxyprogesterone acetophenide (DHPA) and sold under the brand names Perlutal and Topasel among others, is a progestin medication which is used in combination with an estrogen as a form of long-lasting injectable birth control. It has also been used alone, but is no longer available as a standalone medication. DHPA is not active by mouth and is given once a month by injection into muscle.
Medroxyprogesterone acetate (MPA), also known as depot medroxyprogesterone acetate (DMPA) in injectable form and sold under the brand name Depo-Provera among others, is a hormonal medication of the progestin type. It is used as a method of birth control and as a part of menopausal hormone therapy. It is also used to treat endometriosis, abnormal uterine bleeding, paraphilia, and certain types of cancer. The medication is available both alone and in combination with an estrogen. It is taken by mouth, used under the tongue, or by injection into a muscle or fat.
Norethisterone enanthate (NETE), also known as norethindrone enanthate, is a form of hormonal birth control which is used to prevent pregnancy in women. It is used both as a form of progestogen-only injectable birth control and in combined injectable birth control formulations. It may be used following childbirth, miscarriage, or abortion. The failure rate per year in preventing pregnancy for the progestogen-only formulation is 2 per 100 women. Each dose of this form lasts two months with only up to two doses typically recommended.
Hydroxyprogesterone heptanoate (OHPH), also known as hydroxyprogesterone enanthate (OHPE) and sold under the brand names H.O.P., Lutogil A.P., and Lutogyl A.P. among others, is a progestin medication used for progestogenic indications. It has been formulated both alone and in together with estrogens, androgens/anabolic steroids, and other progestogens in several combination preparations. OHPH is given by injection into muscle at regular intervals.
A progestogen ester is an ester of a progestogen or progestin. The prototypical progestogen is progesterone, an endogenous sex hormone. Esterification is frequently employed to improve the pharmacokinetics of steroids, including oral bioavailability, lipophilicity, and elimination half-life. In addition, with intramuscular injection, steroid esters are often absorbed more slowly into the body, allowing for less frequent administration. Many steroid esters function as prodrugs.
Quingestrone, also known as progesterone 3-cyclopentyl enol ether (PCPE) and sold under the brand name Enol-Luteovis, is a progestin medication which was previously used in birth control pills in Italy but is now no longer marketed. It is taken by mouth.
Oxogestone phenpropionate, also known as xinogestone, as well as 20β-hydroxy-19-norprogesterone 20β-(3-phenylpropionate), is a progestin related to the 19-norprogesterone derivatives which was developed as an injectable hormonal contraceptive, specifically a progestogen-only injectable contraceptive, in the 1960s and early 1970s but was never marketed. It was studied at a dose of 50 to 75 mg once a month by intramuscular injection but was associated with a high failure rate with this regimen and was not further developed. OPP is the 20β-(3-phenylpropionate) ester of oxogestone, which, similarly, was never marketed.
17α-Methylprogesterone (17α-MP), or 17α-methylpregn-4-ene-3,20-dione, is a steroidal progestin related to progesterone that was synthesized and characterized in 1949 but was never marketed. Along with ethisterone (1938) and 19-norprogesterone (1951), 17α-MP was one of the earliest derivatives of progesterone to be identified as possessing progestogenic activity. Similarly to progesterone and derivatives like 17α-hydroxyprogesterone and 19-norprogesterone, 17α-MP was found to possess poor oral bioavailability, but showed improved progestogenic activity relative to progesterone when administered via other routes. In addition to its activity as a progestogen, 17α-MP has also been found to possess some antiglucocorticoid activity.
Megestrol caproate, abbreviated as MGC, is a progestin medication which was never marketed. It was developed in Russia in 2002. In animals, MGC shows 10-fold higher progestogenic activity compared to progesterone when both are administered via subcutaneous injection. In addition, MGC has no androgenic, anabolic, or estrogenic activity. The medication was suggested as a potential contraceptive and therapeutic agent.
Estradiol benzoate/progesterone (EB/P4), sold under the brand names Duogynon and Sistocyclin among others, is a combination medication of estradiol benzoate (EB), an estrogen, and progesterone (P4), a progestogen. It has been formulated both as short-acting oil solutions and long-acting microcrystalline aqueous suspensions and is given by injection into muscle either once or continuously at regular intervals.
Methenmadinone caproate is a progestin medication which was developed in Czechoslovakia in the 1960s and was studied for potential use in combined injectable contraceptives in the 1970s but was never marketed. It was studied as a combined injectable contraceptive in combination with estradiol valerate at doses of 60 mg and 10 mg, respectively, once a month by intramuscular injection. MMC is the C17α caproate (hexanoate) ester of methenmadinone and an analogue of methenmadinone acetate. In addition to MMA, analogues of MMC include chlormadinone caproate, gestonorone caproate, hydroxyprogesterone caproate, medroxyprogesterone caproate, and megestrol caproate.
Lynestrenol phenylpropionate (LPP), also known as ethynylestrenol phenylpropionate, is a progestin and a progestogen ester which was developed for potential use as a progestogen-only injectable contraceptive by Organon but was never marketed. It was assessed at doses of 25 to 75 mg in an oil solution once a month by intramuscular injection. LPP was associated with high contraceptive failure at the low dose and with poor cycle control. The medication was found to produce estrogenic effects in the endometrium in women due to transformation into estrogenic metabolites.
Estradiol valerate/gestonorone caproate (EV/GC), known by the developmental code names SH-834 and SH-8.0834, is a high-dose combination medication of estradiol valerate (EV), an estrogen, and gestonorone caproate, a progestin, which was developed and studied by Schering in the 1960s and 1970s for potential use in the treatment of breast cancer in women but was ultimately never marketed. It contained 90 mg EV and 300 mg GC in each 3 mL of oil solution and was intended for use by intramuscular injection once a week. The combination has also been studied incidentally in the treatment of ovarian cancer.
Estradiol benzoate/estradiol valerate/hydroxyprogesterone caproate (EB/EV/OHPC), sold under the brand name Sin-Ol, is a combination medication of estradiol benzoate (EB), an estrogen, estradiol valerate (EV), an estrogen, and hydroxyprogesterone caproate (OHPC), a progestin, which was reportedly used as a combined injectable contraceptive in women in the early 1970s. It contained 1 mg EB, 10 mg EV, and 250 mg OHPC in oil solution, was provided in the form of 3 mL ampoules, and was administered by intramuscular injection at regular intervals. The medication was manufactured by the pharmaceutical company Reuffer in Mexico.
It is the purpose of this paper to introduce and describe a new steroid for oral administration, 17-a-hydroxyprogesterone acetate*, and to compare it with the most widely used oral substance with progestational properties, 20,21-anhydro-17-/3-hydroxyprogesterone. * Prodox, Upjohn Co., Kalamazoo, Michigan [...] It was found that 17-a-hydroxyprogesterone acetate has a progestational activity which is at least twice that of anhydrohydroxyprogesterone.
In 1954, Karl Junkmann of Schering AG reported that the acetylation of the 17-hydroxyl group of ethisterone provided a derivative suitable for formulating in oil for injection intramuscularly as a depot medication.79 There resulted widespread interest in preparing the acetates (and other esters) of various hydroxy-steroids. One such ester, Upjohn's 17-acetoxyprogesterone, provided to be a promising progestogen even though its hydroxy precursor was inactive. Unfortunately, it turned out that no significant prolongation of action was obtained by formulating it in oil. The Upjohn researchers, however, made the unexpected discovery that their acetoxy derivative was orally active, an observation that had been missed by the Schering group, who were primarily interested in the oil solubility of such esters.
[...] The first product was 17alpha-acetoxyprogesterone4 (Figure 1) marketed under the trade name of Prodox.® Prodox was introduced in 1960, was designed for oral use and was not a marketing success. The reasons are not clear as to lack of clear success, but one predominant reason was the high cost. For the average size dog, the cost of preventing estrus for a year was approximately $90. In addition, the inconvenience of daily oral administration may have prevented some market acceptance, especially at that cost. In 1963, Upjohn introduced injectable medroxyprogesterone acetate6 (Figure 1) under the trade name of Promone. Injections were to be made every six months, and this procedure was well accepted by both veterinarians and pet owners. However, Promone sales were discontinued in April, 1966 in the United States for basically two reasons. First was a prolonged and unpredictable return to estrus. This appeared to be due to very slow and variable absorption from the injection site. As a result of this variable absorption rate, one would expect a variable return to estrus. Even after [...]
Chemically pure progesterone was the only substance with progestational properties in general use which could be administered parenterally until Junkmann (1) developed in 1953, 17-alpha-hydroxyprogesterone acetate and 17-alpha-hydroxyprogesterone caproate.
In the group of new parenteral progestational agents, three substances developed by Karl Junkmann1,2 are the most outstanding and interesting: 17a-hydroxyprogesterone caproate and 17a-hydroxyprogesterone acetate, introduced in 1953, and the most potent of all new parenteral progestational agents, 17-ethynyl-19-nortestosterone enanthate, introduced in 1956.
Junkmann of Schering, AG., however, was able to show that long chain esters of 17a-hydroxyprogesterones such as the 17a-caproate produced powerful long-acting progestational effect. [...] Subsequently, a series of events led to the exploitation of 17a-hydroxyprogesterone derivatives as highly effective and orally active progestogens. Groups at Upjohn, Merck & Co., and Syntex independently found means of readily acetylating the 17-hydroxy group. Later, Upjohn announced it found that 17a-acetoxyprogesterone was orally active in humans and subsequently marketed this compound under the name of Prodox.
Prodox Tablets ( Upjohn) A new derivative of progesterone for oral administration. Indications: Secondary amenorrhea, functional uterine bleeding, in- fertility, habitual abortion, dysmen-orrhea and premenstrual tension. Supplied: Tablets containing 25 mg. or 50 mg. of hydroxyprogesterone a c e t a te, in bottles of 25 tablets.
[...] ethisterone, 25 mg. (Lutocylol; Pranone) 17-acetoxyprogesterone, 25 mg. (Prodox), 6-methyl-17-acetoxyprogesterone, 5 mg. (Provera), norethindrone, 5 mg. (Norlutin), norethinodrel, 5 mg. (Enovid). [...]
Hydroxyprogesterone caproate appears to be even less active than Prodox in some respects. It is about 5 times progesterone as an endometrial stimulator [...]
Whereas progesterone is relatively inactive when administered orally, ethisterone (anhydrohydroxyprogesterone) and hydroxyprogesterone acetate are highly active.
17α-Hydroxyprogesterone caproate is a depot progestogen which is entirely free of side actions. The dose required to induce secretory changes in primed endometrium is about 250 mg. per menstrual cycle.
The results showed that after injection the concentration of plasma MA increased rapidly. The meantime of peak plasma MA level was 3rd day, there was a linear relationship between log of plasma MA concentration and time (day) after administration in all subjects, elimination phase half-life t1/2β = 14.35 ± 9.1 days.
[The] minimal activity [of 17(a)-hydroxyprogesterone] is magnified to an unexpected degree by the esterification of this steroid with caproic acid to produce 17(a)-hydroxyprogesterone-17-n-caproate, first reported by Karl Junkmann in 1954.6,7
Junkmann (1954) reported that the acetate, butyrate, and caproate forms had both increased and prolonged activity, [...]
Subsequent acetylation with acetic anhydride and tosyl acid followed by Oppenauer oxidation afforded 17a-acetoxy- progesterone (95) in good yield (115). Tests showed this compound to possess 2-3 times the oral activity of 17-methylpregn-4-ene-3,20-dione (78) and to be many times more potent than progesterone (116,117).
According to Dr. Gordon G. Stocking, director of Upjohn's Veterinary Division, Prodox is a synthetic version of progesterone — one of the hormones that regulates the human female reproductive system. It is 100 per cent effective and has produced no ill-effects on 200 or more dogs on which it has been tested. As a result of its findings, says Dr. Stocking, Upjohn is making the product available through veterinarians.