Medroxyprogesterone acetate, estradiol, FSH and LH in peripheral blood after intramuscular administration of Depo-ProveraR to women

Effects of injectable contraception with depot medroxyprogesterone acetate or norethisterone enanthate on estradiol levels and menstrual, psychological and behavioral measures relevant to HIV risk: The WHICH randomized trial

BACKGROUND

Observational data suggest lower HIV risk with norethisterone enanthate (NET-EN) than with depo-medroxyprogesterone acetate intramuscular (DMPA-IM) injectable contraceptives. If confirmed, a switch between these similar injectable methods would be programmatically feasible and could impact the trajectory of the HIV epidemic. We aimed in this paper to investigate the effects of DMPA-IM and NET-EN on estradiol levels, measures of depression and sexual activity and menstrual effects, relevant to HIV risk; and to ascertain whether these measures are associated with estradiol levels.

METHODS

This open-label trial conducted at two sites in South Africa from 5 November 2018 to 30 November 2019, randomized HIV-negative women aged 18-40 to DMPA-IM 150 mg intramuscular 12-weekly (n = 262) or NET-EN 200 mg intramuscular 8-weekly (n = 259). Data were collected on hormonal, behavioral and menstrual effects at baseline and at 25 weeks (25W).

RESULTS

At 25W, median 17β estradiol levels were substantially lower than at baseline (p<0.001) for both methods: 76.5 pmol/L (interquartile range (IQR) 54.1 to 104.2) in the DMPA-IM group (n = 222), and 69.8 pmol/L (IQR: 55.1 to 89.3) in the NET-EN group (n = 225), with no statistical difference between the two methods (p = 0.450). Compared with DMPA-IM, NET-EN users reported significantly less amenorrhoea, fewer sexual acts, fewer users reporting at least one act of unprotected sex, more condom use with steady partner, more days with urge for sexual intercourse, more days feeling partner does not love her, and more days feeling sad for no reason. We did not find a clear association between estradiol levels and sexual behavior, depression and menstrual effects. Behavioral outcomes suggest less sexual exposure with NET-EN than DMPA-IM. The strength of this evidence is high due to the randomized study design and the consistency of results across the outcomes measured.

CONCLUSIONS

Estradiol levels were reduced to postmenopausal levels by both methods. Secondary outcomes suggesting less sexual exposure with NET-EN are consistent with reported observational evidence of less HIV risk with NET-EN. A randomized trial powered for HIV acquisition is feasible and needed to answer this important question.

TRIAL REGISTRATION

PACTR 202009758229976.

Variability and quantification of serum medroxyprogesterone acetate levels

Quantification of serum progestin levels in clinical contraceptive studies is now routinely performed to understand progestin pharmacokinetics and to correct for unreliable self-reporting of contraceptive use by study participants. Many such studies are focussed on the three-monthly progestin-only intramuscular (IM) injectable contraceptive depot medroxyprogesterone acetate (DMPA-IM). Methods commonly used to measure serum MPA levels include liquid chromatography coupled to mass spectrometry (LC/MS) and radioimmunoassay (RIA); however, RIA methods have not been used in recent years. We review the available literature and find that these methods vary widely in terms of use of organic solvent extraction, use of derivitization and choice of organic solvent and chromatography columns. There is a lack of standardization of LC/MS methodology, including a lack of detailed extraction protocols. Limited evidence suggests that RIA, without organic solvent extraction, likely over-estimates progestin levels. Maximum MPA concentrations in the first two weeks post-injection show wide inter-individual and inter-study variation, regardless of quantification method used. Standardization of quantification methods and sampling time post-injection is required to improve interpretation of clinical data, in particular the side effects arising at different times depending on the pharmacokinetic profile unique to injectable contraceptives.

Initiating Intramuscular Depot Medroxyprogesterone Acetate Increases Frequencies of Th17-like Human Immunodeficiency Virus Target Cells in the Genital Tract of Women in South Africa: A Randomized Trial

BACKGROUND

Cervicovaginal CD4+ T cells are preferential targets for human immunodeficiency virus (HIV) infection and have consequently been used as a proxy measure for HIV susceptibility. The ECHO randomized trial offered a unique opportunity to consider the association between contraceptives and Th17-like cells within a trial designed to evaluate HIV risk. In a mucosal substudy of the ECHO trial, we compared the impact of initiating intramuscular depot medroxyprogesterone acetate (DMPA-IM), copper-IUD, and the levonorgestrel (LNG) implant on cervical T cells.

METHODS

Cervical cytobrushes from 58 women enrolled in the ECHO trial were collected at baseline and 1 month after contraceptive initiation. We phenotyped cervical T cells using multiparameter flow cytometry, characterized the vaginal microbiome using 16s sequencing, and determined proteomic signatures associated with Th17-like cells using mass spectrometry.

RESULTS

Unlike the LNG implant or copper-IUD, DMPA-IM was associated with higher frequencies of cervical Th17-like cells within 1 month of initiation (P = .012), including a highly susceptible, activated population co-expressing CD38, CCR5, and α4β7 (P = .003). After 1 month, women using DMPA-IM also had more Th17-like cells than women using the Cu-IUD (P = .0002) or LNG implant (P = .04). Importantly, in women using DMPA-IM, proteomic signatures signifying enhanced mucosal barrier function were associated with the increased abundance of Th17-like cells. We also found that a non-Lactobacillus-dominant microbiome at baseline was associated with more Th17-like cells post-DMPA-IM (P = .03), although this did not influence barrier function.

CONCLUSIONS

Our data suggest that DMPA-IM-driven accumulation of HIV-susceptible Th17-like cells might be counteracted by their role in maintaining mucosal barrier integrity.

CLINICAL TRIALS REGISTRATION

NCT02550067.

The contraceptive medroxyprogesterone acetate, unlike norethisterone, directly increases R5 HIV-1 infection in human cervical explant tissue at physiologically relevant concentrations

The intramuscular progestin-only injectable contraceptive, depo-medroxyprogesterone acetate (DMPA-IM), is more widely used in Sub-Saharan Africa than another injectable contraceptive, norethisterone enanthate (NET-EN). Epidemiological data show a significant 1.4-fold increased risk of HIV-1 acquisition for DMPA-IM usage, while no such association is shown from limited data for NET-EN. We show that MPA, unlike NET, significantly increases R5-tropic but not X4-tropic HIV-1 replication ex vivo in human endocervical and ectocervical explant tissue from pre-menopausal donors, at physiologically relevant doses. Results support a mechanism whereby MPA, unlike NET, acts via the glucocorticoid receptor (GR) to increase HIV-1 replication in cervical tissue by increasing the relative frequency of CD4+ T cells and activated monocytes. We show that MPA, unlike NET, increases mRNA expression of the CD4 HIV-1 receptor and CCR5 but not CXCR4 chemokine receptors, via the GR. However, increased density of CD4 on CD3+ cells was not observed with MPA by flow cytometry of digested tissue. Results suggest that DMPA-IM may increase HIV-1 acquisition in vivo at least in part via direct effects on cervical tissue to increase founder R5-tropic HIV-1 replication. Our findings support differential biological mechanisms and disaggregation of DMPA-IM and NET-EN regarding HIV-1 acquisition risk category for use in high risk areas.

Hormonal Contraception and HIV-1 Acquisition: Biological Mechanisms

Access to effective affordable contraception is critical for individual and public health. A wide range of hormonal contraceptives (HCs), which differ in composition, concentration of the progestin component, frequency of dosage, and method of administration, is currently available globally. However, the options are rather limited in settings with restricted economic resources that frequently overlap with areas of high HIV-1 prevalence. The predominant contraceptive used in sub-Saharan Africa is the progestin-only three-monthly injectable depot medroxyprogesterone acetate. Determination of whether HCs affect HIV-1 acquisition has been hampered by behavioral differences potentially confounding clinical observational data. Meta-analysis of these studies shows a significant association between depot medroxyprogesterone acetate use and increased risk of HIV-1 acquisition, raising important concerns. No association was found for combined oral contraceptives containing levonorgestrel, nor for the two-monthly injectable contraceptive norethisterone enanthate, although data for norethisterone enanthate are limited. Susceptibility to HIV-1 and other sexually transmitted infections may, however, be dependent on the type of progestin present in the formulation. Several underlying biological mechanisms that may mediate the effect of HCs on HIV-1 and other sexually transmitted infection acquisition have been identified in clinical, animal, and ex vivo studies. A substantial gap exists in the translation of basic research into clinical practice and public health policy. To bridge this gap, we review the current knowledge of underlying mechanisms and biological effects of commonly used progestins. The review sheds light on issues critical for an informed choice of progestins for the identification of safe, effective, acceptable, and affordable contraceptive methods.

Progestins used in endocrine therapy and the implications for the biosynthesis and metabolism of endogenous steroid hormones

Steroidogenesis refers to the de novo synthesis of steroid hormones from cholesterol by a number of sequential enzyme catalysed reactions in the adrenal and the gonads. In addition, circulating steroid hormone precursors are further metabolised in selected peripheral tissues. It has been suggested that the biosynthesis of endogenous steroid hormones can be modulated by progestins, used widely by women in female reproductive medicine. However, as a number of structurally diverse progestins with different pharmacological properties are available, it is possible that these synthetic compounds may vary in their effects on steroidogenesis. This review summarises the evidence indicating that progestins influence the biosynthesis of steroid hormones in the adrenal and gonads, as well as the metabolism of these endogenous hormones in the breast, highlighting the limitations to the current knowledge and directions for future research.

A pilot study of depot medroxyprogesterone acetate pharmacokinetics and weight gain in adolescent females

OBJECTIVE

To explore the relationship between medroxyprogesterone acetate (MPA) pharmacokinetic (PK) parameter estimates and weight gain.

STUDY DESIGN

Prospective study of adolescents (N=40; age 12-21 years) initiating DMPA. PK parameters were calculated: maximum MPA concentration (Cmax, ng/mL), time to Cmax (Tmax, days) and elimination rate constant (ng/mL/day). Optimal PK cut points were determined for predicting body mass index (BMI) increase ≥10%.

RESULTS

Cmax <2.88 ng/mL and elimination rate constant <0.021 ng/mL/day were associated (p<.05) with BMI increase ≥10%. Elimination rate constant was most predictive of weight gain.

CONCLUSIONS

PK evaluation may help identify adolescents at risk of excessive DMPA-associated weight gain.

Bone mineral density assessment in premenopausal women

In the absence of fragility fractures, low bone mineral density may reflect attainment of a lower peak bone mass in comparison with the young adult mean value. It is necessary to distinguish between low peak bone mass and a systemic disorder resulting in low bone mineral density and skeletal fragility. Low peak bone mass in the absence of fragility fracture or progressive bone loss may not require pharmacological intervention. However, systemic disorders contributing to bone loss do require diagnosis and intervention. Common causes of low bone density in premenopausal women include ovulatory disturbances and low body weight. Other diseases, conditions or medications may also contribute to bone loss and these should be identified and treated if present. Fracture risk is reduced by lifestyle changes and pharmacological intervention in those with glucocorticoid-induced bone loss. Discontinuing depo medroxyprogesterone acetate use has been associated with improvements in bone mineral density. Bone mineral density alone is insufficient for the diagnosis of osteoporosis in premenopausal women in the absence of fragility fractures. Bone mineral density testing should only be performed in premenopausal women in the presence of approved indications.

Relationship between weight and bone mineral density in adolescents on hormonal contraception

STUDY OBJECTIVE

Since bone loss has been observed among adolescents on depot medroxyprogesterone acetate (DMPA), a clinical population that commonly experiences weight gain, we were interested in examining the direct relationship between body weight and bone mineral density (BMD) in adolescents on DMPA as compared to those on oral contraceptive pills (OC) or on no hormonal contraception (control).

DESIGN

Prospective, Longitudinal study.

SETTING

Four urban adolescent health clinics in a large metropolitan area.

PARTICIPANTS

Postmenarcheal girls, age 12-18 years, selecting DMPA, OC or no hormonal contraception.

INTERVENTIONS

At baseline, 6, 12, 18, and 24 months, all study participants underwent measurement of weight and BMD of the hip and spine.

MAIN OUTCOME MEASURES

The correlation between weight and BMD, and the correlation between change in weight and change in BMD were assessed at each time point.

RESULTS

Body weight was significantly (P < 0.05) positively correlated with femoral neck BMD and spine BMD at each time point regardless of contraceptive method. Change in body weight at 12 and 24 months was highly correlated with change in femoral neck BMD (P < 0.0001) for all treatment groups. No statistically significant correlation between change in weight and change in spine BMD was seen in the DMPA, OC, or control subjects at 12 or 24 months.

CONCLUSION

Weight gain on DMPA may mitigate loss of BMD among adolescent users.

Serum anti-müllerian hormone level is not altered in women using hormonal contraceptives

BACKGROUND

Anti-müllerian hormone (AMH) is secreted from granulosa cells of antral follicles into the circulation of adult women and hence could serve as an ovarian function test. This would be of value to hormonal contraceptive users if its serum level is unaffected by the use of hormonal contraceptives.

STUDY DESIGN

We prospectively recruited 95 women using combined oral contraceptive (n=23), combined injectable contraceptive (n=23), progestogen-only pills (n=9), progestogen-only injectable (n=20) and levonorgestrel intrauterine system (n=20), and measured their serum AMH concentration before and 3-4 months after treatment.

RESULTS

No significant difference in pre- and post-treatment serum AMH level was evident in all the treatment groups studied.

CONCLUSIONS

Being unaffected by hormonal contraceptives, serum AMH measurement is potentially a useful clinical test in hormonal contraceptive users for the differential diagnosis of anovulatory disorders and determination of menopause.

A longitudinal comparison of body composition changes in adolescent girls receiving hormonal contraception

The objective of this study was to examine body composition changes in adolescent girls initiating depot medroxyprogesterone acetate (DMPA), oral contraceptives, or no hormonal contraceptive method. At 6 months, DMPA resulted in significant increases in adiposity with concomitant decreases in lean body mass. Supplemental estrogen may lessen these DMPA effects.

Management of Low Bone Mineral Density in Premenopausal Women

OBJECTIVE

To review evidence for management of low bone density in premenopausal women and to establish practical guidelines for management of low bone density in this population by family physicians.

METHOD

A search of MEDLINE for relevant articles published between January 1990 and May 2004 was conducted. Articles retrieved were graded by level of evidence. Recommendations for diagnosis and therapy were based on evidence from randomized controlled trials and expert consensus.

RESULTS

Low bone density in premenopausal women is not associated with the same increased risk of fracture seen in older women. In the absence of fragility fractures and loss of height, it may be a reflection of low peak bone mass and may represent the normal variation in bone mineral density (BMD). Women may have low bone density secondary to an underlying skeletal or systemic disorder. Common causes of low bone density in premenopausal women include ovulatory disturbances and low body weight.

CONCLUSION

Osteoporosis is diagnosed in the premenopausal female population in the presence of fragility fractures and is not based solely on the results of BMD testing. Secondary causes of bone loss should be excluded, and any underlying condition contributing to low bone density should be corrected. Antiresorptive therapy has been evaluated only in those premenopausal women who are on glucocorticoid therapy and in those with primary hyperparathyroidism. Only in these conditions has antiresorptive therapy been shown to improve BMD.

Serum medroxyprogesterone acetate levels in new and repeat users of depot medroxyprogesterone acetate at the end of the dosing interval

In the absence of published data on serum medroxyprogesterone acetate (MPA) levels in South African users, this study examines such levels in new and repeat users of depot medroxyprogesterone acetate at the end of the dosing interval. The study was undertaken at three family-planning clinics in Durban, South Africa. Serum MPA levels were measured in 94 Black African, Indian and White women returning between 11 and 14 weeks after their last injection. The median serum MPA level was 0.88 (range, <0.04-1.77) ng/mL and wide interindividual variability was observed. Levels in all but one woman were higher than 0.1 ng/mL, the level at which ovulation is reported to resume. MPA levels were not found to vary according to weight, body mass index or ethnicity. Although there was a slight tendency towards higher MPA levels with longer duration of use (r = 0.13), the wide interindividual variability precluded the possibility of determining whether this was a real trend. A prospective study, using standardized assay techniques and following individual women, is required to further clarify this issue.

Bone density among long-term users of medroxyprogesterone acetate as a contraceptive

The bone density (BD) of 72 women using depot-medroxyprogesterone acetate (DMPA) for at least 1 year was compared with that of 64 women who were not users of hormonal contraceptives. The BD of lumbar spine, femoral neck, Ward's triangle, and trochanter was measured by dual energy X-ray absorptiometry (DEXA-LUNAR DPX). Estradiol (E2) concentrations were measured by radioimmunoassay (RIA). The mean age of DMPA users and nonusers was 31.8 and 31.1 years, respectively. Mean E, was 55.7 pg/mL for users and 149.9 pg/mL for controls (p < 0.001). The BD was significantly lower for DMPA users than for controls in all sites (p < 0.01). In addition, young adult T-scores in the lumbar spine were significantly lower among DMPA users than in controls (p < 0.01). Differences were maintained in a subsample of 47 women per group paired by age and body mass index (BMI). Multiple regression analysis showed that older age, lower BMI, and longer amenorrhea were associated with lower BD in the femoral neck, whereas lower BMI and use of DMPA were associated with lower BD in the lumbar spine.

A patient with a progesterone-producing adrenal adenoma who presented with primary amenorrhea

A case report is presented of a patient with a primary amenorrhea due to a progesterone-producing adrenocortical adenoma. Clinical and endocrinological abnormalities disappeared after removal of the tumor, and the patient experienced her menarche. To our knowledge, a predominantly progesterone-producing adrenal adenoma--in this patient associated with the clinical picture of primary amenorrhea--has not previously been described.

Trabecular bone in long-term depot-medroxyprogesterone acetate users

A cross-sectional study was designed to determine trabecular bone density in 75 long-term depot-medroxyprogesterone acetate (DMPA) users (> 3 yr) matched with non-DMPA users by age, body mass index (18-25), limitation of age (< 45 yr), and body weight (< 60 kg). The long-term DMPA cases were divided into 3 groups according to duration of injectable contraceptive use. Neither cases nor controls had a smoking or chronic alcohol consumption history. Cases and controls were matched by age. Trabecular bone of the femoral neck were assessed by X-ray and interpreted by a single-blinded radiologist. Trabecular bone patterns were graded according to Singh's Index. Blood collection for determination of estradiol, prolactin, calcium, phosphorus, and medroxyprogesterone acetate were performed in cases and controls. Venous blood was taken at twelfth week of injection of DMPA and within 5 days after menstrual bleeding cessation in the controls. Mean trabecular bone in the cases was 5.5 +/- 0.6 (range 4-6). It was not statistically different from that in the controls (mean 5.5 +/- 0.6, range 2-6). No statistically significant difference of serum, calcium, phosphorus, prolactin, and estradiol was seen in the cases when compared to controls at mid follicular phase of normal menstrual cycle. Serum MPA of individual case at twelfth week of injection was 4.1 +/- 1.1 nmol/l. In conclusion, trabecular bone density in long-term DMPA users were not statistically different from normal menstruating women who have not received injectable DMPA.

The effect of medroxyprogesterone acetate (Provera) on ovarian radiosensitivity

Medroxyprogesterone acetate (Provera) is a drug that is commonly given to young women with cancer during chemotherapy and radiation to control heavy bleeding associated with anovulation. Because hypothalamic-pituitary-ovarian suppression has been associated with ovarian protection from the effects of chemotherapy and medroxyprogesterone acetate has been identified as a radiosensitizing agent, we explored the effects of medroxyprogesterone acetate on a rat model with known radiation injury characteristics. Sprague-Dawley rats were treated with medroxyprogesterone acetate or vehicle from day 22 to day 37 of life and were either irradiated or sham-irradiated on day 30 of life and then killed on day 44. Radiation with medroxyprogesterone acetate administration produced a greater loss in preantral and healthy control follicles than in control follicles. No suppression of luteinizing hormone or follicle-stimulating hormone had occurred by day 30 but ovarian glutathione content was reduced. These findings indicate that the administration of medroxyprogesterone acetate with radiotherapy may enhance ovarian injury.

Embryotoxicity of a single dose of medroxyprogesterone acetate (MPA) and maternal serum MPA concentrations in cynomolgus monkey (Macaca fascicularis)

A single dose of MPA (Depo-Provera; Upjohn Co., Kalamazoo, Michigan) was administered intramuscularly to 12 time-mated pregnant cynomolgus monkeys on day 27 (+/- 2) of gestation at 25 mg/kg or at 100 mg/kg. Maternal blood samples were collected immediately prior to MPA injection and then at regular intervals until cesarean section at term (day 152 +/- 3). Infants in both dose groups had external genital abnormalities. Female infants in the low-dose groups had partial or complete labial fusion, prominent median raphe, and clitoral hypertrophy; at high doses (100 mg/kg), the female infants had complete labial fusion and a distinct penile urethra. MPA had an opposite effect on external genitalia of male infants. The penis was short and the scrotal swelling was absent or less conspicuous, and two males had hypospadias. The adrenal glands were significantly smaller (P less than 0.05) in infants of both sexes treated with 100 mg/kg. One of the infants treated with 25 mg/kg of MPA had a muscular ventricular septal defect. Serum concentrations of MPA were determined by radioimmunoassay in eight pregnant monkeys. In the 25 mg/kg group the patterns of MPA profiles in the serum were similar in all four animals. An initial peak occurred at 24-48 hr postinjection (2.7-9.6 ng/ml), followed by a slight decrease at 3 days postinjection (gestational day 30), and then a steady increase to maximum levels of 10-14 ng/ml occurring between gestational days 37 and 50. Serum levels gradually declined to concentrations below 5 ng/ml by midgestation in three of four monkeys. By comparison, both the patterns and magnitude of MPA concentration showed great interanimal variation in the 100 mg/kg group. MPA was present in cord blood at measurable concentrations in infants at both dose groups; the levels ranged from 0.6 to 8.3 ng/ml, corresponding to 40-72% of the maternal concentrations. These results demonstrate that a single injection of MPA during early pregnancy causes selective embryotoxicity in both male and female fetuses. Presence of high levels of MPA in maternal sera during the critical period of genital development can cause specific genital defects; however, the exact mechanism by which MPA causes these paradoxical genital abnormalities is unknown.

Studies on some enzymes and sialic acid during progestational contraceptive therapy

Injectable progestogen, norethisterone enanthate (NET-EN, 200 mg/ml at 60-day intervals), was administered to one-hundred-fifty women for two years as a method of contraception. Blood levels of acid phosphatase (ACP), alkaline phosphatase (AP), glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT), acetylcholinesterase (AChE) and sialic acid were determined in all the subjects to ascertain whether NET-EN therapy causes any adverse metabolic effect or damage to the functional status of the liver. NET-EN contraception did not alter the liver function enzymes, but there is a significant increase (P less than 0.001) in AChE activity after two years. Serum sialic acid level showed a transient increase up to one year, which however returned to control level later. The mechanism responsible for these changes and whether the rise in sialic acid and AChE activity are related to any pathological condition remain unclear at this stage.

Long acting contraceptives. Present status

Long acting injectable hormonal contraceptives are among the most effective fertility regulating agents developed; yet they are also among the most controversial because of animal data indicating a possible carcinogenic potential in several species. A critical analysis of these animal findings has revealed, in all instances, the existence of specific mechanisms not occurring in the human. For this reason, most national and international scientific bodies who have reviewed this issue have concluded that there are no toxicological reasons for not using long acting hormonal contraceptives. Long acting agents can be divided into 2 separate groups: those having a duration of action of one month, which are composed of a long acting oestrogen and a progestagen, and those lasting for several months which consist of only a progestagen. Among the injectable progestagen-only contraceptives tested, only 2 have so far reached the international market: depot medroxyprogesterone acetate (DMPA), which has been administered at 3- or 6-month intervals and norethisterone enanthate, which has been injected at intervals ranging between 2 and 3 months. The most important side effect observed with these 2 agents is a complete disruption of the menstrual bleeding pattern, leading - in some cases - to total amenorrhoea, which is more frequent with depot medroxyprogesterone acetate than with norethisterone enanthate. The latter, however, has a shorter duration of action with a higher pregnancy rate than the former. Other adverse reactions are rare and of no real importance. Metabolic effects with progestagen-only injectable preparations are, in general, mild and less marked than with combined oestrogen-progestagen formulations. Recent investigations have shown that the return of fertility following their use is delayed but in no way impaired. Monthly injectable oestrogen-progestagen combinations have been tested to a more limited extent and these agents are available only in a very few countries. Their main advantage over progestagen-only preparations is that they allow a reasonable menstrual bleeding pattern in the majority of cases. Their obvious disadvantage is that they contain a long acting oestrogen.

Plasma concentrations of megestrol acetate and medroxyprogesterone acetate after single oral administration to healthy subjects

Plasma concentrations of megestrol acetate (MA) were measured by radioimmunoassay (RIA) after a single oral dose of 60 mg either in the form of one tablet, or four 15 mg tablets, to 10 women 21-40 years old using a cross-over design. No statistically significant difference between the two preparations was observed with respect to plasma concentrations, the area under the curve from 0 to 24 h or the maximum concentration (c(max)). For comparison, data are presented on the plasma level of medroxyprogesterone acetate (MPA) following a single oral dose of 100 mg given using a cross-over design in two different tablet forms to 10 healthy men, when no significant difference was observed for these parameters. The mean c(max) for MA after 2.6 h was 43.9 ng/ml (range 21.7-87.7 ng/ml), whereas that for MPA at 3.1 h was 13.1 ng/ml (range 4.4-29.5 ng/ml) despite the higher dose. After 24 h immunoreactive MA and MPA ranged from 9.6 to 29.0 ng/ml and from 0.2 to 4.0 ng/ml respectively. Moreover, it was found that petroleum ether extraction gives the most specific result by RIA, although considerable amounts of metabolites are still co-estimated. By comparison with selected ion monitoring using GC-MS, metabolite interference in RIA increases with time after administration of the steroids and is considerably greater for MPA than for MA. It is concluded that after oral administration the relative bioavailability of MA is significantly better than that of MPA.

Pharmacokinetic approach to the selection of dose schedules for medroxyprogesterone acetate in clinical oncology

The pharmacokinetic and bioavailability properties of medroxyprogesterone acetate (MPA) after single PO and IM doses in man were used as a basis to predict, on a theoretical pharmacokinetic basis, the blood level profile of the drug during repeated dose administration with various dosage schedules. Because of the unusually long-lasting depot effect of IM MPA, a different build-up process of blood levels is expected during repeated IM or PO administration, and this should be taken into account when dose schedules for use in clinical oncology are selected. As regards the IM route, dose schedules based on 4 weeks' treatment with daily injections of 500-1,000 mg followed by a maintenance therapy with 1,000 mg/week are suggested, since they permit rapid achievement and maintenance of relatively high plasma levels. A similar plasma level profile can be obtained with oral MPA provided that daily doses twice as large as the IM doses are given during the first month of treatment and continued during the maintenance period. The serum levels observed in 25 patients with advanced breast cancer treated with MPA given IM or PO according to various dose schedules and recent literature data are very close to the serum level profiles predicted on a theoretical pharmacokinetic basis.

Effects of medroxyprogesterone acetate on socio-sexual behavior of stumptail macaques

Two studies assessed (1) the effect of medroxyprogesterone acetate (MPA), Depo-Provera, on socio-sexual behaviors, and (2) the interaction between socio-environmental conditions and MPA treatment effects. Study One utilized two males and eight female members of a semi-free-ranging island colony. Females received 30 or 100 MPA IM or were untreated. Study Two used three laboratory-housed pairs of tubal-ligated females, observed during 30 min behavior tests with one of three males. Sexually preferred females received 30 mg MPA IM. Semi-free-ranging treated females received fewer ejaculations than untreated females and did not copulate for up to 68 days post-treatment. Rates of grooming were not affected. In the laboratory tests, mean rates of ejaculations per test were reduced for treated females but increased for untreated females, and untreated females groomed males more than did treated females. Contrary to previous studies, these results suggest that stumptail macaque sexual behavior can be influenced by hormones but this influence is modulated by socio-environmental factors.

The Depo-Provera debate. Commentary on the article "Depo-Provera, a critical analysis"

A widely publicized article has in recent months caused a great deal of concern among individuals interested in responsible promotion of family planning. The article contains a long series of factual errors, distortions and biased quotations. This commentary presents evidence, based on current knowledge, that Depo-Provera is a satisfactory contraceptive with several advantages and some disadvantages, and poses no more unresolved problems than oral contraceptives. There is no evidence that, at contraceptive doses, it increases the risk of cancer, impairs bone mineralization, "shocks" the hypothalamus, damages the liver or the immune system, or causes premature aging. Studies to date have not shown damaging effects on infants exposed to the drug in utero or via breast milk. To most women, disruption of the menstrual cycle, the major side effect, is not a health hazard. Finally, women in various parts of the world have shown to be quite capable of choosing for themselves whether or not the advantages of the drug can overcome the disadvantage of almost certain menstrual disturbance.

Studies on ovarian and adrenal steroids at different phases of the menstrual cycle. III. Steroid and lutropin levels before and after the administration of a single contraceptive dose of depot-medroxyprogesterone acetate (DMPA)

Ovarian and adrenal steroids and biologically active lutropin were measured in peripheral plasma samples obtained from 5 normally menstruating women. Plasma samples were collected every 3 h for a period of 39 hours in the periovulatory period of a pretreatment (control) cycle and then 16 and 54 days after a single i.m. injection of 150 mg of depot-medroxyprogesterone acetate (DMPA). Sixteen days after DMA administration, the levels of estradiol, progesterone, 17-hydroxyprogesterone, and lutropin were reduced to early follicular phase levels. No further decrease was found in 17-hydroxyprogesterone and lutropin levels; however an additional decrease occurred in the levels of estradiol and in the "morning" levels of progesterone 54 days after the administration of DMPA. Furthermore, the levels of pregnenolone, androstenedione, testosterone and dihydrotestosterone were significantly diminished in all samples collected after the administration of DMPA. Fifty-four days following the administration of DMPA, the levels of cortisol and 17-hydroxypregnenolone were significantly reduced. The administration of DMPA did not interfere with the circadian rhythm of cortisol, pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, 17-hydroxyprogesterone, and androstenedione levels. A significant circadian rhythm was also found in testosterone (after 16 days) and lutropin (after 54 days) levels. No circadian variation was found in estradiol, progesterone and dihydrotestosterone levels.

Oral high-dose medroxyprogesterone acetate (MAP) in treatment of advanced breast cancer. A preliminary report of clinical and experimental studies

Medroxyprogesterone acetate (MAP) in the treatment of advanced breast cancer has been regarded as a minor agent according to the previous reports when used at low doses (less than 500 mg/day). High doses of more than 500 mg which have come into use since 1973 give a response rate of over 40%, but sometimes cause gluteal abscess or induration because of daily intramuscular injections. In order to administer easily and to avoid the side effect, we have attempted to use oral administration in a daily dose of 1200 mg (400 mg X 3). Of those 20 patients treated with oral high-dose MAP, 1 showed complete response, 6 showed partial response, 7 no change, and 6 progressive disease. As for site of lesion, 4 out of 6 (67%) in skin and 4 out of 16 (25%) in bone responded. Neither severe side effects nor abnormal laboratory data were seen. Then, we examined the blood levels of MAP in vivo by RIA in 9 patients. The blood level of MAP reached 39-250 ng/ml in 3 days and was maintained at least over 50 ng/ml for 1 or 2 months of continuous administration. Subsequently, we examined the effects of MAP on binding to ER in vitro. The inhibition of binding of estradiol-17 beta to ER was about 60% at 10(-5) M MAP. The blood level of 50 ng/ml in vivo corresponds to about 1.3 X 10(-5) M.

Effect of medroxyprogesterone acetate on serum levels of LH, FSH, cortisol, and estrone in patients with endometrial carcinoma

Medroxyprogesterone acetate (MPA) was administered orally for at least 6 months to 25 patients with endometrial adenocarcinoma starting 1 week after hysterectomy and bilateral ovariectomy. We measured serum concentrations of MPA during treatment and serum levels of LH, FSH, cortisol, and estrone before and during treatment with MPA. The serum levels of MPA 3--5 h after ingestion of a daily 100-mg dose of MPA at 08.00 h, varied considerably, the mean value (+/- SE) being 43 +/- 3.6 nmol/l range 15--119 nmol/l. Serum FSH levels rose after operation in the five premenopausal patients and remained elevated despite MPA treatment. In the 20 postmenopausal patients, however, initially high serum FSH and LH levels declined to half the starting values as a result of MPA treatment. After the administration of MPA for 6 months the mean serum cortisol and estrone concentrations at 08.00 a.m. had fallen to 78% and 82% of the mean values before treatment.

Effect of injectable contraceptives Depo-Provera and norethisterone oenanthate on pituitary gonadotropin response to luteinizing hormone-releasing hormone

The pituitary response to luteinizing hormone-releasing hormone (LHRH) was tested in women before and approximately 2, 8, and 12 weeks after the injection of either Depo-Provera or norethisterone oenanthate. The secretion of both luteinizing hormone and follicle-stimulating hormone in response to LHRH was similar in the two groups of women, and the pituitary was capable of responding to LHRH at all times studied after injection of the gestagens. There was no statistically significant difference between the response obtained prior to injection and that at any of the other time periods studied after injection.