The effect of tibolone versus continuous combined norethisterone acetate and oestradiol on memory, libido and mood of postmenopausal women: a pilot study.

Objective: Several studies have shown a positive effect of oestrogen on memory, mood and well-being but these data are controversial and focus particularly on the effect of oestrogen alone. In this pilot study we have investigated the effect of a continuous combination of norethisterone acetate 1 mg and oestradiol valerate 2 mg (Kliogest) versus tibolone (Livial) on memory, sexuality and mood.

Methods: Twenty-two postmenopausal women, age range 51-57, were randomised to a 6 months single blind interventional study treatment with either continuous combined oestradiol plus norethisterone acetate, or tibolone. Computerised psychological test of memory, mood and libido were administered both before and at the end of the 6 months treatment.

Results: Fourteen patients completed the study; eight on Livial and six on Kliogest. Recognition memory was improved by Kliogest but not by Livial (P<0.05) while either drug equally improved both the reaction time (P<0.01) and accuracy of performance (P<0.001) of categorical semantic memory. Both the treatments improved libido significantly (P<0.05), while the mood did not change with either.

Conclusion: The results suggest that both these forms of hormonal replacement therapy improve the efficiency of memory performance and libido. However, a combination of oestradiol and norethisterone acetate seems to be marginally more effective on improving cognitive processes.