Scott E. Monroe

Treatment of endometriosis with a potent agonist of gonadotropin-releasing hormone (nafarelin) *

Administration of superactive agonistic analogs of gonadotropin-releasing hormone (GnRH) has been shown to induce a paradoxic and reversible suppression of gonadotropins, resulting in suppressed gonadal steroid concentrations. Because there currently is no uniformly successful and acceptable medical therapy for endometriosis, we examined the effects of 6 months of nasal administration (500 micrograms every 12 hours) of the agonistic analog of GnRH, nafarelin, on clinical signs and symptoms and hormonal profiles in eight women with endometriosis. All patients had prompt and near-complete relief from their painful symptoms of endometriosis. Laparoscopy or laparotomy, performed both before and after treatment in seven of the women, revealed complete resolution of active endometriotic lesions in five patients and only a single, small cul-de-sac implant in a sixth woman. A large ovarian endometrioma decreased slightly in response to treatment in the seventh woman. Serum luteinizing hormone and follicle-stimulating hormone concentrations, after a transitory stimulation at the onset of treatment, declined and were suppressed (P less than 0.001) during the remainder of treatment. Serum estradiol concentrations fell to approximately menopausal levels (less than 30 pg/ml) after 1 to 4 weeks. Reversibility of drug effect was prompt, with ovulatory menses returning 47 +/- 8 days (+/- standard deviation) after treatment. Thus, nasal administration of agonistic analogs of GnRH may represent a new treatment modality for endometriosis.

Clinical evaluation of the Capronor contraceptive implant: Preliminary report

Capronor, a single-capsule, biodegradable, subdermal contraceptive that releases levonorgestrel over a 12- to 18-month period, has been evaluated in 48 healthy women, ages 18 to 40 years. Sixteen participants received a 2.5 cm capsule (12 mg of levonorgestrel), and 32 received a 4.0 cm capsule (21.6 mg of levonorgestrel). Serum levonorgestrel levels were significantly lower in the 2.5 cm group. Ovulation occurred in all cycles in the 2.5 cm group and in 26.3% of cycles in the 4.0 cm group. Levonorgestrel levels with the shorter capsule were too low for reliable contraception in all users, and 4 cm may be a minimal functional length. Bleeding patterns were regular in most women who ovulated and irregular in most remaining subjects. It is assumed that changes in cervical mucus and the endometrium contributed to effective contraception despite the frequency of ovulation.

Use of an agonistic analog of gonadotropin-releasing hormone (nafarelin) to treat leiomyomas: assessment by magnetic resonance imaging.

The purposes of this study were to investigate the effect of a superactive agonistic analog of gonadotropin-releasing hormone, nafarelin, on uterine leiomyomas and to assess the use of magnetic resonance imaging in monitoring uterine and myoma size. Eleven women with uterine leiomyomas were treated with 800 micrograms of nafarelin per day for 6 months. Serum gonadotropin and estradiol concentrations were suppressed during treatment. The mean +/- SEM serum luteinizing hormone level decreased from 11.1 +/- 1.4 to 5.6 +/- 0.42 mlU/ml and follicle-stimulating hormone from 9.5 +/- 0.66 to 7.5 +/- 0.72 mlU/ml by 3 months of treatment (p less than 0.01). The estradiol level decreased from a pretreatment follicular phase mean +/- SEM of 43 +/- 8.3 to 19.8 +/- 3.1 (p less than 0.05) and 14.8 +/- 2.2 pg/ml (p less than 0.01) at 3 and 6 months of treatment, respectively. Mean pretreatment androgen levels (testosterone, androstenedione, and dehydroepiandrosterone sulfate) were low in these women and did not change significantly during treatment. Ten women had magnetic resonance imaging, which provided excellent resolution of individual uterine myomas. As assessed by magnetic resonance imaging, the largest myoma decreased in size in nine of 10 women; the mean decrease was 46% +/- 9%. Uterine volume decreased in all 10 patients; the mean decrease was 57% +/- 7%. In several women myomas reenlarged after discontinuance of nafarelin treatment. Posttreatment myomectomy was carried out in four women; there was minimal blood loss and no surgical complications. These data indicate that suppression of ovarian estrogen production with nafarelin is associated with a decrease in uterine myoma size in many women but that myomas may regrow with reinstitution of ovarian function. Magnetic resonance imaging is an excellent method by which to monitor treatment as changes in the size of the uterus, as well as individual myomas, can be assessed. The optimal use of gonadotropin-releasing hormone analogs may be in perimenopausal women or as presurgical treatment to decrease uterine and myoma size to facilitate myomectomy.

Suppression of follicular phase pituitary-gonadal function by a potent new gonadotropin-releasing hormone antagonist with reduced histamine-releasing properties (ganirelix) *

OBJECTIVE To determine if daily subcutaneous doses of ganirelix will suppress and maintain E2 < or = 30 pg/mL (conversion factor to SI unit, 3.671), the serum profiles of LH and FSH during and after cessation of treatment, the time-course of the resumption of normal ovarian function after ganirelix cessation, and to identify side effects of daily treatment. DESIGN Open-label nonrandomized clinical study. SETTING Normal human volunteers in an academic research center. PATIENTS Women 21 to 45 years of age, with documented ovulatory menstrual cycles. INTERVENTIONS Ganirelix was administered subcutaneously daily for 8 days. Blood samples were obtained during dosing as well as before and after cessation of dosing. MAIN OUTCOME MEASURES Changes in serum E2, LH, FSH, P, and ganirelix. RESULTS Ganirelix treatment rapidly decreased serum levels of gonadotropins and E2 after both 1 and 2 mg administration. Twenty-four hours after the first dose of ganirelix, E2 decreased from a mean +/- SEM of 50 +/- 8 and 67 +/- 11 pg/mL at baseline to 25 +/- 4 and 20 +/- 3 in the 1 mg and 2 mg groups, respectively. Estradiol remained suppressed (mean levels < 26 pg/mL) on all subsequent 7 days of ganirelix dosing in both groups. After the final dose of ganirelix, there was a rapid return of ovarian function in all volunteers. All women had P levels indicative of ovulation in the subsequent cycle, and the mean number of days from the final ganirelix dose to the next menses was 25.8 +/- 2.1 and 27.3 +/- 1.6 in the 1 and 2 mg groups, respectively. CONCLUSIONS Daily ganirelix administration is effective in suppressing the pituitary-gonadal axis and has a side effect profile that should be well tolerated.

Prolactin-secreting pituitary adenomas in women

A prospective study of 46 women with prolactin-secreting pituitary adenomas and amenorrhea and/or galactorrhea was performed to determine the influence of the selective transsphenoidal removal of these tumors on pituitary and reproductive function. This procedure was effective in restoring menstrual function in 34 of 41 women and in eliminating lactation in 30 of 40 women. Tumor size and preoperative serum prolactin concentrations were the most important factors in predicting the postoperative disappearance of symptoms. Normal menstrual function returned in 33 of 34 women with tumors less than 2 cm in diameter but in only one of seven women with tumors greater than 2 cm. Similarly, galactorrhea disappeared in 29 of 34 women with tumors less than 2 cm but in only one of six women with larger tumors. Menses returned in 31 of 32 women and galactorrhea disappeared in 25 of 31 women with preoperative serum prolactin levels below 200 ng/ml; conversely, menses returned in only three of nine women and lactation ceased in one of six women with preoperative serum prolactin concentrations above 200 ng/ml. Prolactin concentrations decreased in 42 of 43 patients following the removal of pituitary adenomas and returned to normal in 30. Postoperative pituitary reserves of adrenocorticotropic hormone, growth hormone, luteinizing hormone, and follicle-stimulating hormone were normal in most patients. These data indicate that the removal of prolactin-secreting pituitary adenomas by a neurosurgeon accomplished in this surgical technique is effective in restoring menstrual function and eliminating lactation in most women, especially if the tumor is less than 2 cm in diameter and the preoperative serum prolactin concentration is less than 200 ng/ml.

Dose-related suppression of serum luteinizing hormone in women by a potent new gonadotropin-releasing hormone antagonist (Ganirelix)* administered by intranasal spray

OBJECTIVE To determine if the GnRH antagonist (GnRH-a) Ganirelix (Syntex Research, Palo Alto, CA), administered by intranasal (IN) spray to normal women, is absorbed into the systemic circulation and suppresses LH secretion. DESIGN A single center, open label, nonrandomized, dose-escalation study. SETTING Academic research environment. PATIENT(S) Normal female volunteers ages 23 to 43 years. INTERVENTION(S) Ganirelix was administered as a single dose by IN spray. The administered doses and the number of women receiving each of them were 0.1 mg (n = 1), 0.3 mg (n = 1), 1 mg (n = 2), 3 mg (n = 5), and 6 mg (n = 5). Blood samples were collected from -15 minutes to 24 hours after dosing. MAIN OUTCOME MEASURE(S) Serum concentrations of Ganirelix and LH. RESULT(S) Ganirelix was absorbed rapidly. The mean time to maximal serum levels in the 3- and 6-mg groups was 0.67 and 0.53 hour, respectively. Mean serum LH levels were suppressed by > or = 35% relative to baseline from 2 to 12 hours after dosing in both groups. The mean maximal percent decrease in serum LH was -62% (at 8 hours after dosing) and -74% (at 6 hours after dosing) in the 3- and 6-mg groups, respectively. CONCLUSION(S) Single dose IN administration of 3 or 6 mg of Ganirelix suppressed serum LH levels in women, further enhancing the potential clinical utility of this potent GnRH-a. This is the first clinical report of a GnRH-a reducing the secretion of a pituitary gonadotropin when administered by an IN delivery system. Based on the duration and extent of LH suppression observed in this study, Ganirelix, administered by twice daily IN spray, may be effective for the treatment of gonadal hormone-dependent disorders in women.

Ablation of folliculogenesis in women by a single dose of gonadotropin-releasing hormone agonist: significance of time in cycle *

Effects of single subcutaneous doses (1, 5, 20, and 100 micrograms) of nafarelin, a potent gonadotropin-releasing hormone agonist, on the physiologic events of the human menstrual cycle were studied in 28 normal women. Nafarelin entered the circulation rapidly after injection. Peak concentrations were observed within 1 hour, and the plasma half-life was 4 to 5 hours. Maximal concentrations of luteinizing hormone and follicle-stimulating hormone were reached 3 to 4 hours after nafarelin administration. The magnitude of the gonadotropin responses depended both on the phase of the menstrual cycle (smallest responses during the early follicular phase) and the dose of nafarelin. Nafarelin administration during the early follicular phase delayed ovulation by 4.6 +/- 1.7 (standard deviation) days and prolonged the duration of the menstrual cycle from a pretreatment length of 29.2 +/- 2.1 days to 33.4 +/- 4.0 days (P less than 0.001). When nafarelin was administered shortly before or after ovulation, cycle length was not altered consistently. Administration 5 to 10 days after ovulation resulted in a truncated luteal phase. These observations suggest that the hormonal events triggered by nafarelin during the early follicular phase temporarily arrest the process of selection of the dominant follicle. Repeated intermittent administration of nafarelin or other gonadotropin-releasing hormone agonists in the early follicular phase may prevent follicular maturation and ovulation and may be a practical approach to contraceptive development.

Contrasting effects of a gonadotropin-releasing hormone agonist and antagonist on the secretion of free α subunit

Gonadotropin-releasing hormone agonists and antagonists have initial divergent effects on the pituitary secretion of intact biologically active gonadotropins and long-term divergent effects on the secretion of free alpha-subunit. The antagonists appear to function as true competitive inhibitors, blocking the stimulatory effects of endogenous GnRH without evoking any known postreceptor activity. The agonists, in contrast, initially stimulate pituitary secretion and then incompletely desensitize the gonadotrope, resulting in suppression of intact gonadotropin, but not free alpha-subunit, secretion. The mechanisms by which GnRH-a produce this incomplete gonadotrope desensitization and facilitate limited postreceptor activity remain to be elucidated.

Effect on corpus luteum function of luteal phase administration of a potent gonadotropin-releasing hormone analog (nafarelin)*

Fourteen women with ovulatory menstrual cycles were treated with a superactive agonistic analog of gonadotropin-releasing hormone (6-D-[2-naphthyl]-alanyl)-GnRH (nafarelin). Eight of the women received a single subcutaneous injection of nafarelin during the luteal phase at a dosage of 2, 5, or 100 micrograms for determination of the dose-response and pharmacokinetic characteristics of the drug. All doses stimulated the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Maximal release was obtained with the 5-micrograms dose (mean +/- standard deviation: delta LH = 297 +/- 75 mIU/ml; delta FSH = 29 +/- 7 mIU/ml), and there was no greater release of gonadotropin with the 100-micrograms dose. To investigate the contraceptive potential of nafarelin as a luteolytic agent, six of the women were treated with 100 micrograms of analog by daily injection for 10 days, beginning either 2 to 3 days or 5 to 7 days after ovulation. Gonadotroph desensitization or down-regulation developed within 24 hours, but serum concentrations of LH and FSH did not fall below normal values during treatment. There were no significant changes in mean estradiol or progesterone concentrations. There also was no change in mean length of the luteal phase (13.7 +/- 2.1 days [control] versus 13.6 +/- 1.4 days). Thus, nafarelin, like other superactive analogs of GnRH, does not appear to be clinically useful as a luteolytic agent in contraceptive development.

Prolactin-secreting pituitary adenomas in women: VI. Absence of demonstrable adenomas in patients with altered menstrual function and abnormal sellar polytomography

Abstract The clinical and laboratory findings in 115 women with altered menstrual function and abnormal polytomograms were reviewed. All women were treated by transsphenoidal exploration for suspected pituitary adenomas. Adenomas were found in 92 women. Eight patients had cystic lesions which may have represented degenerating tumors. Fifteen women had negative explorations because neither visual nor pathologic evidence of a tumor was found at operation. The incidence of amenorrhea was similar in both the women with documented tumors (87 of 92, 94%) and those with negative explorations (14 of 15, 93%). The incidence of galactorrhea, however, was higher in the women with tumors (85 of 92, 92%) compared to those without tumors (11 of 15, 73%). In addition, all women with tumors had elevated serum prolactin levels (range: 29 to 2,800 ng/ml; median: 130 ng/ml). Of the women with negative explorations, only five of 15 (33%) had elevated prolactin levels (range of elevation: 48 to 143 ng/ml). All patients in this series had abnormal sellar architecture by polytomography prior to operation. All patients in the negative exploration group had central abnormalities of sellar size and shape marked by generalized enlargement without asymmetry. In contrast, x-ray abnormalities in the tumor group were predominantly lateral (87%) with clearly demonstrable asymmetry. In the women with negative explorations, one had primary hypothyroidism, three had hypergonadotropinemia secondary to either premature ovarian failure or surgical oophorectomy, four had partially empty sellae, and two had severe headaches. Based on the findings in this series, the following guidelines for the evaluation of patients with suspected pituitary tumors are suggested: (1) The baseline prolactin level is still the most reliable indicator of a prolactin-secreting pituitary adenoma, although not all patients with hyperprolactinemia have pituitary tumors; (2) hypocycloidal polytomography, at present, is probably the most practical and effective method to assess the sella turcica because central abnormalities of the sella, in contrast to those which show asymmetry, must be scrutinized very carefully prior to surgical exploration; (3) primary thyroid or ovarian failure may be associated with enlargement of the sella without a demonstrable tumor.