Ovulation inhibition by daily i.m. administration of a highly active LH-RH analog (d-ser(TBU)6-LH-RH-(1-9)-nonapeptide-ethylamide)

Cannabinoids and chronic pelvic pain in women: Focus on endometriosis

Chronic pelvic pain in women is common and frequently difficult to treat. Chronic pelvic pain often develops in the setting of endometriosis, interstitial cystitis/bladder pain syndrome, and vulvodynia. Cannabinoids are a promising treatment modality for non-cancer chronic pain, but have not been studied in women with chronic pelvic pain nor in specific chronic pelvic pain conditions. This review focuses on the interaction of the endocannabinoid system with the menstrual cycles, with endometriotic lesions, and within the bladder. Furthermore, it provides a brief overview of existing literature of the effects of endocannabinoids on chronic pain generally, with a focus on neuropathic pain. Finally, it discusses limited data available regarding the use of cannabinoids in women with chronic pelvic pain conditions. In the opinion of the authors, cannabinoids are a reasonable treatment modality for refractory chronic pelvic pain, especially if a neuropathic component is suspected. Practitioners should expect a modest effect on pain levels with an acceptable safety profile.

Buserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical profile

The gonadotrophin releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH); gonadorelin] agonist buserelin is a promising new agent in the treatment of a variety of disorders in gynaecology and andrology, paediatrics and oncology. While a single dose of buserelin stimulates the release of pituitary gonadotrophins, multiple doses produce reversible pituitary desensitisation, and this specific blockade of gonadotrophin support to the gonads provides the basis for the drug's efficacy in conditions dependent on sex hormone secretion. Thus, buserelin provides comparable efficacy to orchidectomy or high dose estrogens in the treatment of hormone-sensitive prostate cancer and exhibits a lower incidence of adverse effects. During the early phase of treatment it may be particularly useful in combination with antiandrogens. Buserelin also appears promising in hormone-sensitive premenopausal breast cancer. Extensive studies have proven the value of buserelin in endometriosis, where it produces a transient remission with gradual recurrence of the disease on cessation of treatment. Surgical intervention is necessary in severe disease after buserelin-induced involution of the lesions. In patients with uterine leiomyoma, preliminary data suggest that buserelin may be beneficial in rendering surgery more conservative by reducing fibroid size, although it appears unlikely to preclude surgical intervention. The use of buserelin to induce a state of reversible hypogonadotrophism before administration of exogenous gonadotrophins is a promising strategy in the treatment of infertility associated with polycystic ovary syndrome and other conditions of infertility with underlying ovarian dysfunction; such a strategy also clearly enhances the efficiency of in vitro fertilisation programmes. Initial studies suggest its potential usefulness as a female contraceptive when administered intermittently in conjunction with a progestogen. Buserelin represents a first-line treatment of central precocious puberty. In endometriosis the adverse effect profile of buserelin is generally favourable, with hypoestrogenic effects such as hot flushes and vaginal dryness, and decreased libido, predominating. There is no apparent detrimental effect on lipid metabolism. The potential for adverse hypoestrogenic effects on bone mineral content with long term administration remains to be clarified. Thus, the GnRH agonist buserelin represents an advance in the treatment of a variety of gynaecological and andrological as well as paediatric and oncological conditions, infertility and other sex-hormone dependent conditions, with a low incidence of adverse treatment effects.

Abolishment of the positive feedback mechanism: a criterion for temporary medical hypophysectomy by LH-RH agonist

The hypothalamic pituitary axis was studied in patients with an abnormal pattern of gonadotropin release during chronic treatment with LH-RH agonist. Two patients had PCOD and the third demonstrated the early luteinization phenomenon. Following a well-defined gonadotropin rise with initiation of LH-RH treatment, no further response was noted. Stabilization of the LH:FSH ratio in PCOD patients was noted after 4 weeks of treatment. Administration of both native LH-RH (100 micrograms) and intravenous pulsatile LH-RH did not evoke any rise in LH. In addition to the above LH-RH challenges, the positive feedback was examined by administration of estradiol benzoate (EB). The study demonstrated that, although the pituitary did not respond to any LH-RH challenge, it may still respond by a rise in LH following EB administration. Both functions of the hypothalamic pituitary axis should be examined in order to determine the state of medical hypophysectomy.

Intranasal peptide contraception by inhibition of ovulation with the gonadotropin-releasing hormone superagonist nafarelin: six months' clinical results

Forty-seven woman volunteers used a new highly potent stimulatory analog of the hypothalamic gonadotropin-releasing hormone (GnRH) for contraception. The superagonist nafarelin acetate, D-Nal(2)6-GnRH, was administered intranasally in one daily dose of 125 micrograms to 25 women and 250 micrograms to 22 women. Ovulation was consistently inhibited during 261 of 262 treatment months. No pregnancy occurred during 222 months in which no additional contraceptives were used. The mean plasma estradiol level after 6 months of treatment was 162 pmol/l. The predominant bleeding pattern was oligomenorrhea. Three women on the lower dose and six women on the higher dose discontinued the trial prematurely, mainly because of hot flushes. No serious side effects were reported. Ovulatory menstruations returned after a median time of 43 days after discontinuation of therapy. Daily intranasal nafarelin treatment for inhibition of ovulation proved to be an effective and rapidly reversible method of contraception.

Dose-related changes in LH bioactivity with intranasal GnRH agonist administration

In order to evaluate changes in bioactive (bio) and immunoreactive (i) LH and in FSH after intranasal administration of a GnRH agonist, two doses (125 micrograms and 250 micrograms) of nafarelin acetate were administered for 14 weeks to 7 normal women. Maximum changes in gonadotropins were observed 2-4 hours after both the first and last doses. However, the maximum acute responses of iLH, bioLH and FSH were significantly reduced after 14 weeks of treatment while no changes occurred in the bio: iLH ratio. The decrease in these acute responses were not dose-related. Serum iLH and FSH levels obtained prior to each dose (baseline) were not significantly altered by 14 weeks with either dose. However, baseline serum bioLH was significantly reduced compared to pretreatment by 14 weeks but only with the 250 micrograms dose (p less than 0.05). This level was also significantly different from the level of bioLH achieved with 125 micrograms (p less than 0.05). The bio: iLH ratio was also significantly decreased with the 250 micrograms dose. Although serum estradiol and progesterone levels suggested ovarian follicular activity and luteinization with the 125 micrograms dose, this did not occur with 250 micrograms of intranasal nafarelin. These data support a dose response effect of intranasal agonist treatment on the bioactivity of LH and also suggest the relevance of measurements of bioLH in assessing the effectiveness of agonist therapy.

Contraception with an LHRH agonist: effect on gonadotrophin and steroid secretion patterns

Chronic treatment with the LHRH agonist D-Ser(TBU)6-LHRH (1-9)-EA (buserelin) has been suggested as a contraceptive method since it has been shown to inhibit ovulation. To elucidate the mechanism of this paradoxical action, we investigated the pattern of gonadotrophin and steroid secretion after the daily intranasal application of 300 micrograms of the agonist. Ten volunteers with ovulatory cycles received the analogue from Day 1 to Day 22 and 5 mg norethisterone acetate from Day 16 to Day 22. Blood samples were taken on Day 1, 15, and 21 every 15 min for 6 h after the application of the agonist. LH secretion was increased nine-fold on the first treatment day as compared to Day 2 of the preceding control cycle. Thereafter, it decreased slowly but was still elevated five-fold on Day 21 of treatment. FSH release increased three-fold on Day 1 but decreased thereafter to values similar to those of the controls. During treatment with the analogue, the LH/FSH ratio changed from 1.3 (controls) to 3.8 on Day 1 and to 5.5 on Day 15 and 21 of treatment. Although the ovary retained follicular activity, ovulation was inhibited in every treatment cycle. This seemed to be due to an impairment of follicular steroid synthesis as indicated by a significant increase of 17 alpha-hydroxyprogesterone and testosterone levels for several hours after the application of the analogue. It appears that at least during the first treatment cycle of daily administration of buserelin the abolishment of pulsatile gonadotrophin release, and the abnormally increased ratio of LH/FSH secretion may possibly impair follicular maturation and thus contribute to the inhibition of ovulation.

Luteinizing hormone-releasing hormone (LHRH) and its analogs for contraception in women: a review

In animals, LHRH agonists have multiple sites of action including the pituitary, the gonads, and the reproductive tract. In humans, the major antifertility action of this class of peptides is believed to be mediated via the pituitary. Studies in women have indicated that potent LHRH agonists can block ovulation when administered once daily. In the volunteers who have used these agents no serious side effects were observed, although some women experienced irregular bleeding or amenorrhea. It is anticipated that formal clinical trials could be conducted in the near future to determine the efficacy of continuous LHRH agonist administration. Early attempts to use an LHRH agonist to produce luteal insufficiency, luteolysis, or interruption of pregnancy have either been unsuccessful or the results are still too preliminary to ascertain whether these approaches warrant further trials. LHRH antagonists are believed to act by inhibiting the action of LHRH on the pituitary. Although some of these peptides are known to be active in women, very large doses have been required. Recently several investigators have produced LHRH antagonists with increased potency. In the near future, it should be possible to determine whether these peptides should be considered as potential contraceptives in men or in women.

Peptide contraception in women. Inhibition of ovulation by chronic intranasal LRH agonist therapy

Seventy-one healthy female volunteers used the LRH superagonist D-Ser(TBU) 6-EA10-LRH (buserelin) for contraception during 3-26 months. One daily dose of 200-600 micrograms was administered by the nasal route. No pregnancy occurred during the 628 treatment months. The bleeding pattern varied from fairly regular menstrual bleedings (n = 26) to oligomenorrhoea (n = 27) and amenorrhoea (n = 18). No severe or dysfunctional bleeding disturbances were observed. No signs of hyperplastic changes of the endometrium were found in 57 endometrial biopsies. After cessation of the long-term treatment normal ovulation and menstruation returned after 41.3 days, on average. Thus, intranasal administration of an LRH agonist for inhibition of ovulation is a promising new contraceptive method for women.

Clinical applications of LHRH and its analogues

The physiological requirement for activation of pituitary gonadotrophin secretion by pulsatile LHRH stimulation is discussed, and compared with the effect of pituitary stimulation by LHRH agonists. Initial stimulation is followed by a phase of progressive pituitary and gonadal inhibition. This inhibition is fully reversible at the end of agonist treatment. Clinical applications of high dose suppression are the treatment of precocious puberty and hormone-dependent tumours (mammary and prostatic carcinoma). In women, agonist administration by nasal spray is a reversible method of inhibiting ovulation, and may also be useful in the treatment of endometriosis. Clinical advantages of agonist therapy are favourable biological tolerance, lack of side effects and rapid reversibility.

Assessment of pituitary secretory capacity in women with hypogonadotrophic hypogonadism by using a long-acting synthetic analogue of luteinizing hormone releasing factor

The gonadotrophin responses to single and repeated injections of a long-acting synthetic analogue of luteinizing hormone releasing factor (LRF), d-Ser(TBU)6EA10LHRH, were investigated in 10 women with normoprolactinaemic hypogonadotrophic hypogonadism. Abnormal luteinizing hormone (LH) responses were observed in two of the five patients treated with 5 micrograms of the analogue and in all five patients treated with three injections of 10, 20 and 10 micrograms administered at intervals of 10-14 h. However, the LH response to repeated injections of the analogue was of similar magnitude and duration to that observed in normal women in response to an oestrogen provocation test in the early-to-mid follicular phase of the cycle. Thus failure of the LH response to oestrogen provocation in women with hypogonadotrophism results from hypothalamic rather than primary pituitary dysfunction. This study confirms the usefulness of this analogue of LRF in the assessment of pituitary secretory function in women with abnormal responses to oestrogen positive feed-back.

Influence of the LH-RH analogue buserelin on cyclic ovarian function and on endometrium. A new approach to fertility control?

The long-acting stimulatory luteinizing hormone - releasing hormone analogue D-Ser(TBU)6-EA10-LH-RH (buserelin) was administered intranasally once daily in a dose of 400 mcg to 24 normally ovulating women and to 4 women with pre-existing endocrine dysregulation. Ovulation was inhibited in 136 out of 156 treatment months. In 20 treatment months, progesterone values temporarily increased indicating luteinization of follicles or ovulation with defective corpus luteum function. Estradiol secretion showed a tendency to lower values as treatment progressed but individually indicated follicle maturation until the end of the observed medication period. Bleeding pattern ranged from menses-like bleeding in regular as well as irregular intervals to amenorrhea. The morphological findings of 31 endometrial biopsies of 20 volunteers ranged from atrophy (n = 4) to proliferation (n = 25) with early signs of hyperplasia as well as early secretory transformation (n = 2). The morphological alterations indicate that unopposed estrogen stimulation of the endometrium is the main problem of long-term contraception with the dose schedule of buserelin used.