Inhibitory and stimulatory actions of danazol in rat ovarian and uterine tissues

Danazol for uterine fibroids

BACKGROUND

Uterine fibroids (myomas, fibromyomas, leiomyomas) are the most common benign tumours of the female genital tract. Danazol, a synthetic isoxazole derivative chemically related to 17-ethinyl testosterone, has been used for many years for the treatment of women with uterine fibroids.

OBJECTIVES

To evaluate the effectiveness and safety of danazol in women with uterine fibroids.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Review Group Specialised Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 4); MEDLINE; EMBASE; Chinese Biomedical Disc; and the China National Knowledge Infrastructure for relevant trials (to December 2008). Attempts were made to identify trials from references in published studies. We also searched for ongoing trials in the five major clinical trials registries.

SELECTION CRITERIA

Randomised controlled trials of danazol versus placebo or any other medical therapy in women with uterine fibroids confirmed by medical procedures, regardless of the women's symptoms or age. Women with malignancies were excluded.

DATA COLLECTION AND ANALYSIS

Data extraction and risk of bias assessment were not been performed because there were no identified studies.

MAIN RESULTS

We did not identify any studies which met our full inclusion criteria.

AUTHORS' CONCLUSIONS

There is no reliable evidence available from randomised controlled trials regarding the benefits and or harms of the use of danazol for treating uterine fibroids.

Effects of carbamazepine on the first ovulation in gonadotropin-primed immature female rats

1. The effects of carbamazepine (CBZ) and its possible mechanisms on the first ovulation were investigated in immature female rats. The first ovulation was induced by administration of equine chorionic gonadotropin (eCG) at 0800 h at 26 days of age. 2. A single s.c. injection of 360 mg x kg(-1) CBZ at 1300 h on the first pro-oestrus (day 28) completely inhibited the first ovulation on the morning of day 29. A marked elevation in 13, 14-dihydro-prostaglandin F2alpha (13, 14H2-PGF2alpha) forming capacity, a sensitive indicator of luteinizing hormone (LH) surge, was not detected in the CBZ-treated group at 0800 h on day 29 (72 h after eCG treatment). The elevation in serum LH levels at 57 h after eCG treatment was not observed in the CBZ-treated group, either. The blocking of the first ovulation and 13, 14H2-PGF2alpha forming capacity were recovered by an i.p. injection of human CG on day 28 in all animals. 3. However, the first ovulation was not blocked by repeated injections of 360 mg x kg(-1) CBZ at 1300 h once daily for 3 days (days 26 - 28). The repeated injections of CBZ caused a great fall (64% decrease) in the serum levels of CBZ at 4 h after the final CBZ injection as compared with the case of a single injection of CBZ and resulted in a delay for 5 h the occurrence of LH surge, which is normally observed around 57 h after eCG injection. 4. A significant increase in the activity of microsomal CBZ catabolism by the repeated injections of CBZ was quantitatively verified by the HPLC analysis. But, the activity of CBZ metabolism in the single injected-animals showed almost similar levels to that in the control. 5. The present results demonstrated that a single injection of CBZ blocks the ovulation by inhibiting LH surge but that the failure of the inhibition of ovulation by repeated injections of CBZ is due to a decrease in serum CBZ levels mediated through CBZ-induced hepatic enzyme induction.

Effect of particle size on the prolonged action of subcutaneous danazol in male and female rats

OBJECTIVE

To investigate the effects of two different particle sizes of danazol in male and female rats.

DESIGN

Prospective, vehicle-controlled study.

SETTING

Undergraduate college research facility and medical research laboratory.

ANIMALS

18 castrated male rats and 18 cycling female rats.

INTERVENTION(S)

Preparations of danazol with particle sizes of 2.05 microm or 5.2 microm were administered as a single subcutaneous injection of 400 mg/kg to castrated male rats or estrus-cycling females.

MAIN OUTCOME MEASURE(S)

Serum LH level in males and estrous cycle length in females.

RESULT(S)

In males, both preparations significantly (P<. 001) suppressed serum LH by day 5 of treatment. Gonadotropin levels remained low throughout the 35-day study in rats that received the larger-particle danazol, whereas LH levels began to increase after 25 days in rats that received smaller-particle danazol. In females, the normal 4- to 5-day estrous cycle interval was prolonged to 38.7 days (P<.001) in those that received the larger-particle danazol and 25.5 days in those that received the smaller-particle danazol.

CONCLUSION(S)

The results demonstrate the prolonged effectiveness of a single subcutaneous dose of danazol and indicate that one might be able to predict the effective duration of activity by changing the particle size of the danazol administered.