Objective: To establish the potency of four dose levels of tibolone, a tissue selective estrogenic activity regulator (STEAR), to relieve climacteric symptoms in a subgroup of highly symptomatic women experiencing a minimum of seven hot flushes and sweats per day.
Methods: In a group of 770 women receiving tibolone 0.625, 1.25, 2.5 or 5.0 mg or placebo for 12 weeks, a total of 317 women experienced at least seven hot flushes and sweats per day. Frequency and intensity of climacteric symptoms were assessed at baseline and after 4, 8 and 12 weeks of treatment. Vaginal bleeding/spotting was studied using diary cards. Occurrence of adverse events was determined by active questioning.
Results: Tibolone induced a decrease in the frequency and intensity of climacteric symptoms, leading to statistically significant differences compared to placebo for dose levels of 1.25 mg and higher. The incidence of vaginal bleeding/spotting and of drug-related adverse events was similar in all tibolone dose groups, except for the 5.0 mg group, where the incidence was about twice as high. Dropout rate due to insufficient therapeutic effect is substantially higher in the 0.625 and 1.25 mg group (about 10%) compared to the 2.5 and 5.0 mg group (about 1%). These results are consistent with what occurred in the total study population published previously.
Conclusion: The effects of tibolone in highly symptomatic women experiencing at least seven hot flushes and sweats per day do not differ much from that in the total study population. A daily dose of 2.5 mg is the optimal dose for both the total study population and the subgroup of highly symptomatic women. However, in order to optimise individual treatment, the 1.25 mg dose might also be taken into consideration.