The effects of add-back therapy with tibolone on myoma uteri

In this prospective, randomized, double-blind study, we evaluated the effects of tibolone therapy in association with preoperative gonadotropin releasing hormone agonist (GnRHa) therapy on the reduction of myoma volume. Twenty patients with myoma uteri were divided into two groups. Group I was given monthly triptoreline (3.75 mg every 28 days IM) treatment for six months. As for group II, tibolone was added on to this treatment. For all of the patients, physical examinations, pelvic ultrasonography, and hormone analyses were carried out and the myoma volume was measured by ultrasonography. The patients were called every month and physical examination, ultrasonography and hormone analyses were repeated. Side-effects were recorded. The SPSS/PC 6.0 program was used for statistical analysis. Statistical significance was defined as a p < 0.05. The results are expressed as means ± SD. While the average volume of myoma was 72.97 ± 68.5 cm3 in group I, 78.83 ± 74.1 cm3 in group II before treatment; it was reduced to 29.91 ± 27.8 cm3 in group I at the end of six months of treatment. Reductions of 59.6% in group I and 63.9% in group II were determined, however the difference was not statistically significant (p > 0.05). At the beginning the level of serum estradiol was 65.4 ± 22.3 pg/ml in group I which decreased to 37.2 ± 4.2 pg/ml by the end of the first month. Amenorrhea occurred in six patients after the second injection and four patients after the third injection in group I. Whereas the level of estradiol was 60.9 ± 19.5 pg/ml in group II at the beginning, it was reduced to 40.5 ± 6.2 pg/ml by the end of the first month. Amenorrhea occurred in four patients after the second injection and four patients after the third injection in group II. In group I the patients had the problem of flushing (80%), vaginal dryness (50%), and night sweats (30%). In group II these rates were 30%, 20%, and 20%, respectively. Triptoreline is a GnRHa which has been found to be effective in reducing myoma volume, but this effect could not be deactivated with tibolone. However, a decrease was observed in the side-effects resulting from hypoestrogenism.