Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Livial (Organon Australia)
5 mg tablets
Approved indication: postmenopausal symptoms and bone loss
Australian Medicines Handbook Section 17.2.3
Tibolone is a synthetic steroid with oestrogenic and progestogenic activity. It can therefore be used to treat menopausal symptoms such as hot flushes.
The activity of the drug involves several metabolites. These are rapidly formed after absorption so plasma concentrations of tibolone are very low. Only small amounts are excreted in the urine.
Several studies have assessed the effect of tibolone on bone density. One study followed healthy postmenopausal women for two years. Women who took 2.5 mg tibolone daily had increases in bone density, while bone density fell in the control group. By the end of the study, there were significant differences in bone density between the groups in the upper femur and lumbar spine.1
Another study compared tibolone with oral or transdermal hormone replacement therapy. After two years, bone density was preserved in women who were treated, compared with untreated controls. There were no significant differences in efficacy between tibolone and hormone replacement therapy.2
As tibolone has some progestogenic effects it may have an advantage over oestrogen alone, e.g. the risk of breast cancer may be reduced. However, endometrial proliferation can still occur and lead to vaginal bleeding. Any abnormal bleeding occurring after three months of treatment should be investigated. Compared with placebo, more patients taking tibolone experience leukorrhoea, vaginitis, breast pain and weight gain.
Tibolone reduces triglyceride concentrations, but can also reduce HDL cholesterol. As it may increase fibrinolytic activity there is a potential for interaction with anticoagulants. Drugs which induce liver enzymes, such as carbamazepine and rifampicin, may decrease the effect of tibolone.
Although tibolone has been available overseas for several years its place in therapy is not clear. While it can prevent reductions in bone mineral density its effectiveness in preventing fractures is unknown.
