Osphena (ospemifene)

Ospemifene, a triphenylethylene derivative, is a tissue-selective, estrogen agonist-antagonist.

Ospemifene is a tissue-selective, estrogen agonist-antagonist; the drug also is referred to as a selective estrogen receptor modulator (SERM). Ospemifene has mixed estrogen agonist and antagonist activities, which result in activation of estrogenic pathways in some tissues and blockade of estrogenic pathways in other tissues. The drug binds to estrogen receptor (ER)alpha and ERbeta, with stronger binding occurring at the ERalpha receptor.

In animal studies, the drug exhibited strong estrogenic effects on vaginal epithelium; these effects were also demonstrated in clinical trials (e.g., improvement in the maturation index, decreased vaginal pH, decreased symptoms such as dyspareunia and vaginal dryness).

Ospemifene has been shown to have estrogenic effects on bone in rats; in healthy postmenopausal women, ospemifene reduced biochemical markers of bone turnover. However, further studies assessing bone mineral density (BMD) and fracture risk are needed to evaluate ospemifene's clinical effects on bone.

In postmenopausal women, ospemifene at a dosage of 60 mg daily did not have a substantial effect on serum lipoprotein concentrations (i.e., total, low-density lipoprotein (LDL)-, or high-density lipoprotein (HDL)-cholesterol, or triglyceride concentrations).

In clinical trials, ospemifene had weak estrogenic effects on the endometrium. Postmenopausal women receiving ospemifene for up to 1 year demonstrated slight dose-related mean increases in endometrial thickness compared with patients receiving placebo, but no cases of endometrial cancer were observed. (See Genitourinary Effects under Warnings/Precautions: Warnings, in Cautions.)

Preclinical in vitro and in vivo data suggest ospemifene may have breast antiestrogenic activity in several breast cancer models, but these effects have not been assessed in clinical trials. (See Breast Cancer under Other Warnings/Precautions: Warnings/Precautions, in Cautions.)

Following oral administration of a single 60-mg dose of ospemifene with a high-fat, high-calorie meal, the drug is rapidly absorbed with peak serum concentrations attained at approximately 2.5 hours after the dose. Peak serum concentration and area under the serum concentration-time curve (AUC) of ospemifene are increased when the drug is taken with food. Ospemifene is highly bound to serum proteins and has a half-life of approximately 26 hours.

The drug undergoes metabolism mainly via cytochrome P-450 (CYP) isoenzymes 3A4 and 2C9; other isoenzymes (CYP2C19 and 2B6) also play a role in the metabolism of the drug. The major metabolite is 4-hydroxyospemifene. After oral administration of ospemifene, 75% of the dose is excreted in feces and 7% is excreted in urine.

USES: This medication is used to treat painful sexual intercourse and vaginal dryness in women after menopause. Painful intercourse and vaginal dryness are symptoms of changes in and around your vagina, due to menopause. This drug is different from hormones (including estrogens and progestins).

It works by acting like estrogen in some parts of the body. Ospemifene belongs to a class of drugs known as selective estrogen receptor modulators (SERM).

Generic name: ospemifene
Pronunciation: (os-PEM-i-feen)

The following indications are listed for Osphena:

• Atrophic Vaginitis Associated With Menopause
• Dyspareunia Due To Menopause-Associated Vulvovaginal Atrophy

Also known as: Senile Vaginitis, Vaginitis Senilis.

No ICD codes are available for this drug.