Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): assessment of return of ovulation after three monthly injections in surgically sterile women

The pharmacodynamic effects of medroxyprogesterone acetate (MPA) and estradiol cypionate (E2C) (MPA/E2C) (Lunelle Monthly Contraceptive Injection) on ovarian function were assessed through changes in serum progesterone concentrations. The data described here were obtained simultaneously with pharmacokinetic data presented in another article in this issue. Sixteen surgically sterile women with regular menstrual cycles were studied for one control cycle, three consecutive treatment months, and 3-5 months of follow-up. Suppression, followed by resumption of ovulation (the dynamic end point), was assessed by serum progesterone levels. Return of ovulation was presumptive based on progesterone concentrations > or = 4.7 ng/mL, as ultrasound was not used to determine the follicular/ovulatory status of these subjects. Luteal-like serum progesterone peaks were observed in all 16 women before drug administration, confirming the presence of ovulatory cycles. After the third monthly injection of MPA/E2C, progesterone concentrations were measured until demonstration of ovulation. Two women discontinued and three were lost to follow-up before this objective was achieved. Serum progesterone levels and, consequently, ovulation were suppressed beyond the entire dosing interval, indicated by the absence of any luteal-like progesterone peaks (serum progesterone concentrations did not exceed 1 ng/mL). The first normal ovulatory cycle, based on progesterone concentrations > or = 4.7 ng/mL, was observed in 11 women between days 63 and 112 after the third injection. Select medroxyprogesterone acetate parameters (i.e., area under the curve and minimum concentration) were correlated with return of ovulation. The correlation coefficients (r) were 0.757 and 0.492 for area under the curve and minimum concentration, respectively, indicating that return of ovulation is dependent, in part, on area under the curve and on the magnitude of the serum MPA trough level. In general, the higher the minimum concentration levels, the longer the time to return of ovulation. In conclusion, the return of ovulation, as confirmed by serum progesterone concentrations > or = 4.7 ng/mL, was observed as early as 63 days after the third and final monthly intramuscular injection of MPA/E2C, suggesting that consistent suppression of the hypothalamic-pituitary-ovarian axis is reversible after discontinuation of dosing.

Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): effects of body weight and injection sites on pharmacokinetics

A new contraceptive option, medroxyprogesterone acetate (MPA) and estradiol cypionate (E2C) (MPA/E2C, Lunelle Monthly Contraceptive Injection), will soon be available for women in the US. This article reports the results of a US trial that assessed the effects of body weight and injection site on the pharmacokinetics of MPA, the progestin mediating contraceptive efficacy. This assessment was part of a nonrandomized, open-label, multicenter US study in healthy women receiving a monthly injection of MPA/E2C for 60 weeks. A total of 77 women (aged 18-47 years) at four centers participated in the pharmacokinetics assessment during the sixth or the seventh injection. For determination of serum MPA concentration-time profiles, blood samples were collected before the sixth and seventh injections (day 0) and on days 3, 7, 14, 21, and 28 after the sixth and seventh monthly administrations. For effects of injection site, MPA pharmacokinetics were compared at injection sites of the arm, hip, and leg. The pharmacokinetics of MPA, determined at the sixth and seventh injection, were not significantly affected by injection sites. The mean area under the curve (AUC0-28), however, was different between the arm and the leg injection sites; the difference was < 20%. More important, the average MPA trough concentrations (Cmin) at the fifth and sixth monthly injections were similar (range 0.42-0.51 ng/mL) for the three injection sites and well above the threshold levels of 0.10-0.20 ng/mL required to suppress ovulation. For effects of body mass index (BMI) on pharmacokinetics, women were stratified into three groups: thin/normal (BMI 18-28, n = 48), obese (BMI 29-38, n = 23), and highly obese (BMI > 38, n = 6). There were no significant differences in the pharmacokinetics of MPA among the three BMI categories. The only significant difference (p = 0.0387) was the AUC0-28 between BMI 18-28 and BMI 29-38. Because of the small sample size in the highly obese group, a reanalysis was performed by pooling subjects of the obese and highly obese groups. Results of the pooled statistical analysis remained the same. In summary, these results suggest that minor differences observed in the MPA pharmacokinetics--whether due to injection site or body weight or both--have no impact on the contraceptive efficacy of MPA/E2C, as trough concentrations (Cmin) are well above the threshold levels required to suppress ovulation. No dose adjustment is necessary based on body weight or injection site.

Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): steady-state pharmacokinetics of MPA and E2 in surgically sterile women

The steady-state pharmacokinetics and pharmacodynamics of medroxyprogesterone acetate (MPA) and estradiol (E2, released from E2C by esterase enzymes) were characterized after administration to surgically sterile women. This report describes the pharmacokinetics of this multiple-dose and open-labeled study (pharmacodynamics are reported in a subsequent article in this issue). Women with regular menstrual cycles were studied for one control cycle, 3 consecutive treatment months, and 3-5 months of follow-up. Blood samples were drawn before each monthly dose and at specified time points after the third monthly injection. A total of 16 women were enrolled, 14 of whom completed the study. These 14 women (13 white, one black) ranged in age from 28 to 43.4 years, in body weight from 47.6 to 68.9 kg, and in height from 150 to 175 cm. Mean serum MPA concentrations peaked in the first week after administration of MPA/E2C (Lunelle Monthly Contraceptive Injection). The mean MPA Cmax and AUC0-t(last) were 1.25 ng/mL and 32.13 ng.day/mL, respectively. Serum MPA concentrations declined with a mean terminal half-life of 14.7 days, indicating that absorption from the injection site is prolonged after administration of MPA/E2C. The time for MPA concentrations to fall below the lower limit of quantitation (i.e., < 10 pg/mL) after the third injection ranged from 63 to 84 days. The average MPA trough (Cmin' day 28) concentrations for the three consecutive monthly injections ranged from 0.44 to 0.47 pg/mL, indicating that steady-state conditions were achieved after the first injection. The MPA Cmin values were well above threshold levels required to suppress ovulation throughout the injection interval. Absorption of E2 from the injection site was also prolonged after injection of MPA/E2C. Mean concentrations of E2 peaked at approximately 2 days after the third injection, and the average Cmax was 247 pg/mL. Serum E2 levels declined with a terminal half-life of approximately 8 days; E2 levels returned to baseline (typically, approximately 100 pg/mL) by 14 days after each injection. The average trough (Cmin' day 28) levels for E2 ranged from 40 to 55 pg/mL. The results of this study demonstrate that steady-state conditions are achieved after the first injection of MPA/E2C; no further MPA or E2 accumulation occurs beyond the first injection. Furthermore, the E2 peak observed after injection of MPA/E2C is similar to the nontreated preovulatory E2 range and returns to baseline levels by approximately 14 days after injection.

Long-term depot-medroxyprogesterone acetate and bone mineral density

The association between long-term use of depot-medroxyprogesterone acetate (DMPA) and bone mineral density (BMD) has been controversial, as seen in three case-control studies in New Zealand, Thailand, and the United Kingdom. In the present case-controlled study of BMD, a group of 67 Chinese women who had used DMPA from 5-15 years was compared with 218 women of the same age range who had not used any steroidal hormones. DMPA users were found to have a significantly lower BMD at lumbar vertebra (L2-4) (0.93 g/cm2), neck of femur (0.69 g/cm2), trochanter (0.59 g/cm2), and Ward's triangle (0.58 g/cm2), as compared with the control group, whose corresponding BMD values were 1.03 g/cm2, 0.83 g/cm2, 0.71 g/cm2, and 0.78 g/cm2, respectively (p < 0.001). The average percentage of bone loss per year was estimated to be 1.1% in L2-4, 2.3% in neck of femur, 2.4% in trochanter, and 3.5% in Ward's triangle. The percentage of bone loss in L2-4 was found to be more pronounced with age. This study provided information that the use of DMPA in a Chinese group for > 5 years in associated with bone loss, and a prospective study is needed to confirm these data, which are different from two case-control studies.

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.

Bone density in long term users of depot medroxyprogesterone acetate

OBJECTIVE

To identify any adverse effect on bone density in long term users of depot medroxyprogesterone acetate (DMPA) for contraception.

DESIGN

Cross-sectional measurement of bone density in users with amenorrhoea of more than one year or any woman using DMPA for more than five years.

SETTING

Community Family Planning Clinics in Portsmouth and Manchester.

POPULATION

One hundred and eighty-five women aged 17-52 years (mean 33.3 years) who had used DMPA for between 1 and 16 years and were attending the clinics for further injections, between August 1994 and August 1996.

METHODS

Dual energy X-ray measurement of bone density of femoral neck and lumbar spine, and venous blood sample taken just prior to the next injection of DMPA.

MAIN OUTCOME MEASURES

Bone density of femoral neck and lumbar spine and serum oestradiol in relationship to years of DMPA use and duration of amenorrhoea.

RESULTS

Most women (n=153) had serum oestradiol levels < 150 pmol/l. Despite this, the mean bone density of the lumbar spine compared with the population mean for women aged 20-59 years gave a Z score (95% CI) of -0.332 (-0.510 to -0.154). There was no significant difference in the mean density of the femoral neck from the normal population mean.

CONCLUSION

Despite amenorrhoea and low serum oestradiol, this sample of long term DMPA users had bone density only minimally below the normal population mean. We therefore found no clinically important adverse effect on bone density and therefore no reason to recommend bone conserving measures, such as add-back oestrogen.

Introduction of cyclofem once-a-month injectable contraceptive in Mexico

A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.

Pharmacokinetics of medroxyprogesterone acetate after single and multiple injection of Cyclofem in Chinese women

To provide pharmacokinetic data for safety evaluation on prolonged treatment with Cyclofem, which contains 25 mg medroxyprogesterone acetate (MPA) and 5 mg estradiol cypionate in 0.5 mL microcrystalline aqueous suspension, the pharmacokinetic profiles of MPA after single and multiple administration of this monthly injectable contraceptive were investigated in Chinese women. Nine healthy fertile women received Cyclofem based on a once-a-month regiment for up to 1 year. Blood samples were collected immediately prior to drug administration and on days 1, 3, 5, 7, 14, 21, and 28 after injection. After the 1st, 6th, and 12th injection, the maximum serum concentrations (Cmax) of MPA were observed on days 3.4 +/- 0.9, 4.3 +/- 2.2, and 3.7 +/- 2.6, respectively. Cmax of serum MPA during the 1st, 6th, and 12th treatment cycles were 3.75 +/- 1.27, 5.54 +/- 1.79, and 5.55 +/- 1.80 nmol/L, whereas the areas under the curve (AUC0-28 days) were 55.84 +/- 28.15, 95.45 +/- 26.56, and 98.81 +/- 21.84 nmol/L.day, respectively. There was significant interindividual variation in the pharmacokinetics of MPA after intramuscular injection of Cyclofem. No significant change was demonstrated in mean residence time (MRT) of MPA after single and multiple injection. There was a tendency of increase in Cmax and AUC0-28 days of MPA during the first 6 months of treatment, whereas no further enhancement was found between the 6th and 12th injection (p > 0.05). Peak levels of estradiol (E2) observed in Cyclofem users were within the normal range of the preovulatory phase. Results of this long-term study suggest that no drug accumulation occurred after repeated administration of Cyclofem in the Chinese women.

Timing of onset of contraceptive effectiveness in Depo-Provera users: Part I. Changes in cervical mucus

OBJECTIVE

To evaluate the changes in cervical mucus within the first hours or days after depot medroxyprogesterone acetate (MPA) injection so as to estimate the time at which cervical mucus becomes hostile enough to prevent pregnancy.

DESIGN

Multicenter, clinical descriptive study.

SETTING

Family planning clinic.

PATIENT(S)

Thirty women who were between days 8 and 13 of their menstrual cycle and who had requested Depo-Provera were enrolled in the study.

INTERVENTION(S)

Cervical mucus and blood samples were obtained; transvaginal ultrasonography was performed.

MAIN OUTCOME MEASURE(S)

Cervical mucus scores, sperm penetration distances, ovarian follicular size, and serum levels of progesterone and estradiol.

RESULT(S)

From 6 to 24 hours after injection, there was a sharp decline in the cervical mucus score for most of the subjects. All subjects exhibited poor mucus on day 3 after injection, and by day 7, all subjects had zero scores, with the exception of two outliers on each day. Sperm penetration, as measured by the vanguard sperm distance, was already poor (< 1 cm) in 7 of the 30 subjects at the time of injection and was reduced progressively up to 24 hours after injection, when only four subjects had a sperm penetration of > 1 cm. A rapid decline in the estimated number of sperm was observed at 12 hours and more so at 24 hours in the majority of subjects.

CONCLUSION(S)

The data presented in this report confirmed that depot MPA causes profound changes in cervical mucus after injection. Although very little change was seen at 6 hours, alterations were observed subsequently, with 90% of the subjects showing a poor cervical mucus score 24 hours after administration of the progestin. No reliable clinical marker is available to identify in which women depot MPA might exert its effect on cervical mucus within 3 days. Thus, we believe that at present, women should be informed of this uncertainty and should use a backup method of contraception for 7 days when the first injection of depot MPA is provided after the seventh day of the menstrual cycle.

Return of fertility after discontinuation of the once-a-month injectable contraceptive Cyclofem

The objective of this study was to evaluate the return of fertility in women who used Cyclofem as a contraceptive method during the introductory studies conducted in Brazil, Chile, Colombia, and Peru. From these four cohorts, 101 women were eligible for the study. Thirty-one were not included in the study either because they refused to be interviewed, had initiated another contraceptive method the month after discontinuation, or were unable to be contacted. A total of 70 women were included in the study. Our results showed that the return to fertility rate after the discontinuation of Cyclofem was 1.4 per 100 women at the end of the first month and reached 82.9 at one year. More than 50% were pregnant at 6 months. Fifty-one (94.4%) pregnancies ended in a live birth, two were spontaneous first trimester abortions, and one was a hydatidiform mole. Return of fertility was not related to the woman's age at the time of discontinuation, her weight, or the number of Cyclofem injections. In conclusion, fertility is restored by 1 month following Cyclofem discontinuation. Users and potential users should be counseled regarding the rapid return of fertility after discontinuing this method of contraception.

Establishing the minimum effective dose and additive effects of depot progestin in suppression of human spermatogenesis by a testosterone depot

Hormonally induced azoospermia induced by weekly im injections of testosterone enanthate provides effective and reversible male contraception, but more practical regimens are needed. Given our previous findings that six 200-mg pellets implanted subdermally produced more stable, physiological T levels and reduced the delivered T dose by more than 50% while maintaining equally effective suppression of sperm output with fewer metabolic side-effects than weekly 200-mg testosterone enanthate injections, we sought in this study to determine 1) whether further dose-sparing could be achieved by lower testosterone doses while maintaining efficacy and 2) the efficacy of adding a depot progestin to a suboptimally suppressive depot testosterone dose as a model depot progestin/androgen combination male contraceptive. Healthy volunteers were randomized into groups (n = 10) who received either of two lower T doses (two or four 200-mg T pellets) or four 200-mg T pellets plus a single im injection of 300 mg depot medroxyprogesterone acetate (DMPA). Two T pellets (400 mg, 3 mg/day) had a negligible effect on sperm output. Four T pellets (800 mg, 6 mg/day) suppressed sperm output between the second to fourth postimplant months; output returned to normal by the seventh postimplant month, although only 4 of 10 men became azoospermic or severely oligozoospermic (< 3 mol/L/mL). The addition of a depot progestin markedly increased the extent, but not the rate, of sperm output suppression, with 9 of 10 becoming azoospermic and 10 of 10 becoming severely oligozoospermic. There were no serious adverse effects during the study. Plasma total and free testosterone levels remained within the eugonadal range at all times with each treatment. Plasma epitestosterone was suppressed by all 3 regimens, consistent with a dose-dependent inhibition of endogenous Leydig cell steroidogenesis. Plasma LH and FSH measured by a two-site immunoassay were suppressed in a dose-dependent fashion by T and further suppressed by the addition of DMPA. Sex hormone-binding globulin levels were decreased by DMPA, but not by either T dose. Prostate-specific antigen and lipids (total, low or high density lipoprotein cholesterol, and triglycerides) were not significantly changed in any group. Thus, a depot testosterone preparation with zero order release must be delivered at between 6-9 mg/day to provide optimal (but not uniform) efficacy at inducing azoospermia. The addition of a single depot dose of a progestin to a suboptimal testosterone dose (6 mg/day) markedly enhances the extent, but not the rate, of spermatogenic suppression, with negligible biochemical androgenic side-effects. These findings provide a basis for the use of a progestin/androgen combination depot for hormonal male contraception.

A comparative study on the return to ovulation following chronic use of once-a-month injectable contraceptives

A comparative study was undertaken involving 21 Mexican women who discontinued the use of medroxyprogesterone acetate 25 mg plus oestradiol cypionate 5 mg (Cyclofem) and norethisterone enanthate 50 mg plus oestradiol valerate 5 mg (Mesigyna) to assess the time required for the return to menses and ovulation. All subjects were exposed to once-a-month injectable contraceptives for two years and were followed for 120 days after the last injection. The urinary concentration of oestrone glucuronide and pregnanediol glucuronide was determined daily in all subjects beginning one month after the last injection. The results disclosed that ovulatory cycles were documented after 120 days of the last injection in six women of each studied group. Similar endometrial bleeding patterns were observed in both groups, indicating that the two drugs have alike pharmacokinetic and pharmacodynamic effects.

Long-acting injectable contraception with depot medroxyprogesterone acetate

Depot medroxyprogesterone acetate (DMPA) is the only injectable contraceptive available in the United States. After more than 20 years of regulatory review, the Food and Drug Administration approved DMPA for contraceptive use in 1992 after the publication of reassuring data about its possible association with breast cancer. It has been used by 30 million women in more than 90 countries. The recommended dosage, 150 mg intramuscularly every 3 months, has a contraceptive efficacy exceeding 99%. After a 150 mg dose, ovulation is inhibited for at least 14 weeks. Almost all users experience menstrual changes, typically episodes of unpredictable irregular spotting and bleeding, particularly during the first year of use. With continued use, spotting and bleeding decrease, and amenorrhea becomes common. Although ovulation suppression may rarely persist for as long as 18 months after the last injection, DMPA does not permanently affect fertility. Long-term DMPA use reduces menstrual blood loss, has been associated with a decreased incidence of candidal vulvovaginitis and pelvic inflammatory disease, and dramatically lowers the risk of endometrial cancer. Prolonged DMPA use may be associated with reversible reduction in bone density, probably related to suppression of endogenous production of estrogen. The most recently published data suggest that long-term use of DMPA induces moderate changes in lipid metabolism that are unfavorable in terms of risk of atherosclerosis. DMPA should be considered a highly effective, safe, convenient, and reversible contraceptive option for appropriately selected patients.

Comparative assessment of the effects of subdermal levonorgestrel implant system and long acting progestogen injection method on lipid metabolism

In order to compare the effects of two type of long-acting progestogen contraceptive methods with subdermal levonorgestrel (LNG) implants and depot-medroxyprogesterone acetate (DMPA) injections on lipid metabolism, a clinical cohort study was performed by requiring 25 women in each group adopting either LNG implant or DMPA injection method voluntarily. After 6 months of use, serum levels of triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol were determined and compared between the two groups of acceptors. The mean of total cholesterol in LNG implant acceptors was significantly lower than that in DMPA injection acceptors. The mean values of HDL-cholesterol in LNG implant acceptors (41.7 +/- 7.7 mg/dl) and in DMPA injection acceptors (45.0 +/- 9.0 mg/dl) were in the normal range without significant difference between the two groups. The mean value of triglycerides did not differ significantly between LNG implant acceptors (77.6 +/- 25.1 mg/dl) and DMPA injection acceptors (91.0 +/- 30.3 mg/dl). Serum concentrations of lipid fractions such as HDL-cholesterol and LDL-cholesterol in LNG implant acceptors were relatively low compared to those in DMPA injection acceptors. Since there was a comparable reduction in both total-and HDL-cholesterol levels in the LNG implant group, the ratio of total-to HDL-cholesterol, which is thought to be a factor in determining the risk of coronary artery disease, remained in the normal range (2 +/- 4.5). This suggests that the use of these two contraceptive methods with progestogens does not alter the risk of development of coronary artery disease.

Sequential regimen of the antiprogesterone RU486 and synthetic progestin for contraception

OBJECTIVE

To examine the effect of sequential use of the antiprogesterone RU486 and synthetic progestin on ovarian function of healthy women.

DESIGN

Healthy women were given a sequential antiprogesterone-progestin treatment. Blood samples were taken twice a week during one control cycle and one to three treatment cycles; prospective analysis.

SETTING

The outpatient clinic of the Helsinki City Maternity Hospital, Helsinki, Finland, and Steroid Research Laboratory, Department of Medical Chemistry, University of Helsinki, Helsinki, Finland.

PATIENTS

Eleven healthy women, volunteers, 20 to 34 years of age.

INTERVENTIONS

A dose of 25 mg/d of RU486 was given during cycle days 1 to 21, and synthetic progestin (5 mg of norethisterone to six and 5 mg of medroxyprogesterone acetate to five women) during cycle days 22 to 31.

MAIN OUTCOME MEASURES

Serum P, E2, FSH, and LH were measured from serum samples.

RESULTS

In 20 of the 24 treatment cycles analyzed the serum concentrations of P were anovulatory. In the remaining 4 cycles, P levels rose above 3 ng/mL, suggestive of ovulation. Folliculogenesis was not completely inhibited, but serum E2 profiles were subnormal and delayed. Bleeding control was satisfactory.

CONCLUSIONS

Antiprogesterone RU486 hampers or delays follicular development, suggesting a possible use as an estrogen-free oral contraceptive. However, the synthetic progestins used in this regimen induced serum P rises in some cycles. The synthetic progestin provides the cycle control, but its possible effect on the reliability of the method remains to be evaluated.

Concentration of fat, protein, lactose and energy in milk of mothers using hormonal contraceptives

Energy, protein, lactose and fat were studied in the milk of mothers who were using different types of contraceptives. One hundred and eleven mothers made up the following groups. C: control (barrier and natural methods, or sterilization), n = 22; combined pill: LDP (low dose pill (levonorgestrel 0.15 mg + ethinylestradiol 0.03 mg)), n = 12 and MDP (medium dose pill (levonorgestrel 0.25 mg + ethinylestradiol 0.05 mg)), n = 13; MP (minipill (norethindrone 0.35 mg)), n = 37; DMPA (injectable progesterone (depot medroxiprogesterone acetate 150 mg)), n = 17; and IUD (plastic or copper intrauterine device), n = 10. The mean stages of lactation were, respectively, 15, 17, 5, 9, 5 and 9 weeks. The mean duration of observation for the study groups ranged from 2 to 4 weeks. Milk samples were collected before and after initiation of treatment (mean = 20 days; range = 14-103 days). The stage of lactation and the interval of nursing before sampling were recorded so that statistical account could be taken of these uncontrollable sources of variability. When incorporated as covariates, they showed that no significant differences existed between the groups tested, either before or after treatment.

High progesterone receptor concentration in a variant of the ZR-75-1 human breast cancer cell line adapted to growth in oestrogen free conditions

Culture of ZR-75-1 human breast cancer cells for 5 days in the absence of oestrogens (phenol red-free medium supplemented with dextran coated charcoal stripped 5% fetal calf serum) resulted in a slowing of growth rate and loss of progesterone receptors. Oestradiol at 10(-9) M markedly stimulated growth and progesterone receptor synthesis over a 5-day period. While medroxyprogesterone acetate (10(-10) to 10(-6) M) inhibited growth of ZR-75-1 cells growing in complete medium, in the short-term absence of oestrogens low concentrations were growth stimulatory. Cells deprived of oestrogens for 5 days retained sensitivity to growth inhibition by 4-hydroxy tamoxifen. ZR-75-1 cells were also adapted to growth in the absence of oestrogens over a 5-month period. These cells (ZR-PR-LT) failed to express binding sites characteristic of the type 1 oestrogen receptor but progesterone receptor expression was at a level normally associated with oestrogen induction. Adapted cells were growth inhibited by oestradiol, 4-hydroxy tamoxifen and medroxyprogesterone acetate, but despite elevated progesterone receptor expression the progestin was only marginally more inhibitory than in the parent line. Our data indicate a poor quantitative relationship between response to progestins in vitro and progesterone receptor concentration and support previous findings that acquisition of an oestrogen independent phenotype does not necessarily result in resistance to anti-oestrogens.

Opioidergic regulation of LH pulsatility in women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCO) display disordered patterns of LH pulsatility and may have an impairment of opioidergic regulation of GnRH-LH. In order to ascertain if these patterns reflect an inherent hypothalamic abnormality or a functional state consequent to the acyclicity of sex steroids, LH pulsatility and gonadotrophin responses to naloxone were examined in six PCO women before and after treatment with incremental daily doses of a progestogen, medroxyprogesterone acetate (MPA), for 10 days to determine (i) if progestogen treatment would alter the LH pulse pattern to resemble that of the luteal phase; and (ii) if the conversion to a luteal phase LH pulse pattern by MPA would involve the induction of opioidergic regulation. LH pulsatility and FSH levels were determined by blood sampling at 10 min intervals for 8 h before and after MPA treatment during a saline infusion on the control day and during a naloxone infusion (1.6 mg/h) on the following day. Basal levels of oestradiol, oestrone, androstenedione, testosterone, and dehydroepiandrosterone-sulphate were measured before and after MPA. All six PCO women responded to MPA administration with a significant reduction in LH pulse frequency (P less than 0.005), an increase in LH pulse amplitude (P less than 0.0025), and an increase in LH pulse duration (P less than 0.025), without changes in mean LH, mean FSH, androgen, or oestrogen levels. Thus, a luteal phase LH pulse pattern was induced by MPA. Naloxone reversed the MPA-induced changes in LH pulsatility, indicating that these responses involved the induction of central opioidergic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Return of ovulation following a single injection of depo-medroxyprogesterone acetate: a pharmacokinetic and pharmacodynamic study

The effect of a single dose of 150 mg of depo-medroxyprogesterone acetate (DMPA) on pituitary, ovarian and endometrial function was assessed in relation to the peripheral levels of the compound in 8 women. The levels of medroxyprogesterone acetate (MPA), follitropin (FSH), lutropin (LH), prolactin, estradiol (E2) and progesterone ( Prog .) were measured 3 times a week during a pretreatment (control) cycle and then daily during postinjection weeks 14-17, 22-25 and 30-33. An endometrial biopsy specimen was obtained during postinjection weeks 17, 25 and 33. In three out of 8 subjects the daily hormone assays carried out during postinjection weeks 30-33 indicated anovulatory periods; in these subjects peripheral blood was drawn daily during postinjection weeks 46-49 and a fourth endometrial biopsy was taken during week 49.

Long acting injectable hormonal contraceptives

Injectable hormonal preparations can be highly effective and satisfactory contraceptives. The two main preparations available today are depot medroxy progesterone acetate (DMPA) and norethisterone oenanthate (NET-OEN), but several other approaches are currently under clinical trial. Injectable contraceptives have some unique advantages which give them justifiably wide appeal amongst many groups of women. However, they do have a number of disadvantages including invariable menstrual disturbance and a delay in the return of fertility. One formulation of DMPA, Depo-Provera, is probably the most extensively investigated single hormonal contraceptive ever made. These studies indicate that it is remarkably safe and does not face any more unresolved issues than the combined pill, intrauterine device or tubal sterilization. However, for a number of disparate emotional and political reasons it has attracted the attention of several consumer and feminist groups, who have waged a prolonged and quite unjustified campaign against it. It is to be hoped that future debate will be conducted on a more informed, rational and less emotional basis. Injectable contraceptives should have an important place in the family planning armamentarium of all countries, and current developments should lead to a decrease in concerns about presently available agents. This should further increase the widespread acceptability of this approach to contraception.

On the mechanism of action of progestins

The effect of two synthetic injectable progestins, norethisterone oenanthate3 (NET-e) and medroxyprogesterone acetate (MPA) upon the hypothalamic pituitary unit was evaluated in post-menopausal women (PMW) and in castrated individuals with androgen un-responsiveness in order to gain insight into their mechanism of gonadotrophin inhibition. Continuous administration of natural progesterone (P4) to PMW by medicated vaginal rings was used as the experimental control. Elevated base line levels of serum immunoreactive gonadotrophins and normal pituitary LRH responses were found in PMW and pseudohermaphrodites. Progesterone did not affect circulating gonadotrophin levels or the pituitary LRH response in PMW.

Administration of MPA 150 mg induced a clear decrease in serum gonadotrophins and a significant decrease in LRH pituitary responsiveness in a post-menopausal woman whereas no effect was observed on serum gonadotrophins and pituitary response to LRH in a patient with androgen unresponsiveness. Administration of NET-e 200 mg resulted in a significant decrease in circulating gonadotrophins in PMW and pseudohermaphrodites, while LRH pituitary sensitivity was diminished in all subjects except one post-menopausal woman.

These results demonstrated that two structurally different synthetic progestins (NET-e and MPA) had a potent gonadotrophin inhibitory activity in PMW while natural progesterone did not, thus indicating a different mode of action. Furthermore their differing effect on individuals with complete androgen unresponsiveness suggested that antigonadotrophic activity of NET-e is mediated by its oestrogenic-progestational effect, while MPA acts through its androgenic potency and therefore requires the presence of androgen receptors.

Effects of a long-acting progestin on reproductive function in female mice

The duration of activity of a long-acting progestin, medroxyprogesterone acetate, was compared using three tests for progestational activity: the induction of stromal mitosis in the endometrium, implantation of blastocysts and inhibition of ovulation. The duration of activity was similar in each test and was longer when higher doses were given.

Adrenocortical involution in rats during oestrus synchronisation with medroxyprogesterone

Daily treatment of female rats with medroxyprogesterone acetate in aqueous suspension resulted in adrenocortical atrophy. The doses given were those used for oestrus synchronisation. Intramuscular injections of 2-0 mg medroxyprogesterone acetate were used to investigate the atrophic process. Adrenocortical involution was associated with extensive single cell deletion (apoptosis). It is suggested that theses changes were due to suppression of pituitary ACTH secretion. The cytological changes support the concept that single cell death plays an important role in organ remodelling. Biochemical determinations of DNA, RNA, protein and dry matter, and histological examination, did not reveal significant changes in the liver.