OVESTIN

What it is

Ovestin Ovula is a pessary containing 0.5 mg estriol. The pessaries are white to light cream coloured torpedo shaped pessaries of uniform texture. Ovestin contains the natural female hormone estriol. Estriol is short acting since it has only a short retention time in the nuclei of endometrial cells.

Approved indications

Ovestin Ovula is indicated for vulvo-vaginal complaints due to estrogen deficiency associated with the climacteric and the postmenopause or after ovariectomy: — <cite index="1-4">Atrophic vaginitis — Pruritus vulvae — Dyspareunia due to vulvo-vaginal atrophy — As auxiliary therapy in the treatment of vaginal infections — As pre-operative therapy for vulvo-vaginal surgery and during subsequent convalescence — Ulcers in cases of prolapse of the uterus or vagina — To avoid misinterpretation of a cytological smear

Dosing overview

For vulvo-vaginal complaints associated with the menopause, the usual dosage is one pessary per day for 2–3 weeks initially. As maintenance dosage, one pessary once or twice a week is recommended. Medication should be discontinued every 2 to 3 months for a period of 4 weeks to assess the necessity for further treatment. For pre-surgery therapy, one pessary per day should begin 2 weeks before the operation. In the case of a suspect cytological smear, a daily application of 0.5 mg estriol for 7 days is recommended before re-evaluating the cytology. Ovestin Ovula is intended for intravaginal administration, before retiring at night.

Key safety warnings

For the treatment of postmenopausal symptoms, hormone replacement therapy should only be initiated for symptoms that adversely affect quality of life. In all cases, a careful appraisal of the risks and benefits should be undertaken at least annually and HRT should only be continued as long as the benefit outweighs the risk. One epidemiological study has shown that long-term treatment with low doses of oral estriol, but not vaginal estriol, may increase the risk for endometrial cancer. This risk increases with the duration of treatment and disappeared within one year after the treatment was terminated. Vaginal bleeding during medication should always be investigated. The patient should be informed to contact a doctor if vaginal bleeding occurs. HRT is associated with a higher relative risk of developing venous thromboembolism (VTE), that is deep vein thrombosis or pulmonary embolism. One randomized controlled trial and epidemiological studies found a 2–3 fold higher risk for users compared with non-users. These studies did not include Ovestin and, in the absence of data, it is unknown whether Ovestin carries the same risk. Clinical studies reported that the likelihood of developing increased mammographic density was lower in subjects treated with estriol than in subjects treated with other estrogens. In a population-based case-control study in 3,345 women with invasive breast cancer and 3,454 controls, estriol was found not to be associated with an increased risk of breast cancer, in contrast to other estrogens. In the small number of women using vaginal or other topical HRT preparations, no increased risk of breast cancer was observed.

Contraindications

Ovestin Ovula is contraindicated in pregnancy, known past or suspected breast cancer, known or suspected estrogen-dependent malignant tumours such as carcinoma of the endometrium, undiagnosed genital bleeding, previous or current active venous thromboembolism (deep venous thrombosis, pulmonary embolism), known thrombophilic disorders (for example protein C, protein S, or antithrombin deficiency), a history of recurrent venous thromboembolism or known thrombophilic disease in a patient who is not already on anticoagulant treatment, active or recent arterial thromboembolism (for example angina, myocardial infarction), thrombophlebitis or a past history of this condition, a history during pregnancy or previous use of steroids of a manifestation or deterioration of otosclerosis, endometriosis, untreated endometrial hyperplasia, porphyria, severe liver dysfunction or a history of liver disease as long as liver function tests failed to return to normal, disturbed lipid metabolism particularly in the presence of other risk factors which may indicate a predisposition to cardiovascular disorders, and hypersensitivity to the active substances or to any of the excipients.

PBS listing

Ovestin Ovula pessaries 500 micrograms (15 pessaries) are listed on the PBS with an ex-manufacturer price of A$11.91. There are 2 PBS items listed, with restriction types being both unrestricted and restricted.

Regulatory history

Ovestin Ovula (estriol 0.5 mg pessary) was first listed on the ARTG on 23 November 1992. The date of first approval was 23 November 1992.