ospemifene

General

Pronunciation:
os- pem-i-feen

Trade Name(s)

• Osphena

Ther. Class.
hormones

Pharm. Class.
estrogen agonists/antagonists

Indications

Moderate to severe dyspareunia due to menopausal vulvar/vaginal atrophy.

Action

Has agonist (estrogen-like) effects on the endometrium of the uterus; effects are tissue-specific.

Therapeutic Effect(s):

Decreased dyspareunuia.

Pharmacokinetics

Absorption: Well absorbed following oral administration; food enhances absorption 2–3 fold.

Distribution: Unknown.

Protein Binding: >99%.

Metabolism and Excretion: Mostly metabolized by the liver (CYP3A4 and CYP2C9 enzyme systems); 75% excreted in feces, 7% in urine as metabolites; minimal amounts excreted unchanged in urine.

Half-life: 26 hr.

TIME/ACTION PROFILE (improvement in symptoms)

Contraindication/Precautions

Contraindicated in:

• Hypersensitivity
• Undiagnosed abnormal genital bleeding;
• History/ suspicion of estrogen-dependent cancer;
• History of/current thromboembolic disorder, including DVT, PE, MI, or stroke;
• Concurrent use of estrogens, estrogen agonists/antagonists, fluconazole, or rifampin;
• OB: Known/suspected pregnancy (may cause fetal harm);
• Lactation: Breast feeding should be avoided.

Use Cautiously in:

• Patients with risk factors for cardiovascular disease, arterial vascular disease, or venous thromboembolism (including hypertension, obesity, family history, tobacco use, diabetes mellitus, history of DVT/PE, or systemic lupus erythematosus);
• Known or suspected breast cancer;
• Severe hepatic impairment.

Adverse Reactions/Side Effects

CV: STROKE, DEEP VEIN THROMBOSIS/PE

GU: ENDOMETRIAL CANCER, genital/vaginal discharge

Derm: hot flush, hyperhydrosis

MS: muscle spasms

Misc: HYPERSENSITIVITY REACTIONS INCLUDING ANGIOEDEMA

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

• Blood levels, effects and risk of adverse reactions ↑ by fluconazole, avoid concurrent use.
• Blood levels and effects may be ↑ by ketoconazole or other drugs that inhibit the CYP3A4 or CYP2C9 enzyme systems.
• Blood levels and beneficial effects ↓ by rifampin, avoid concurrent use.
• Avoid concurrent use of other estrogens or estrogen agonist/antagonists due to ↑ estrogen effects.
• May displace or be displaced by other drugs that are highly protein bound.

Route/Dosage

PO (Adults) 60 mg once daily.

Availability

Tablets: 60 mg

Assessment

• Assess amount of pain during intercourse prior to and periodically during therapy.
• Determine methods previously use to treat dyspareunia.
• Assess BP before and periodically during therapy.
• Monitor for hypersensitivity reactions (angioedema, urticaria, rash, pruritus). If symptoms occur discontinue ospemifene and treat symptomatically.

Potential Diagnoses

• Sexual dysfunction (Indications)
• Deficient knowledge, related to medication regimen (Patient/Family/Teaching)

Implementation

• PO Administer once daily with food.

Patient/Family Teaching

• Instruct patient to take ospemifene as directed. Advise patient to read Patient Information sheet before starting therapy and with each Rx refill in case of changes.
• Advise patient to report signs and symptoms of unusual vaginal bleeding, changes in vision or speech, sudden new severe headaches, severe pains in chest or legs with or without shortness of breath, weakness, or fatigue promptly to health care professional.
• Inform patient that ospemifene may cause hot flashes, vaginal discharge, muscle spasm, and increased sweating.
• Patients who still have a uterus should discuss addition of progestin with health care professional.
• Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
• Advise patient to notify health care professional of medication regimen before treatment or surgery.
• Women should be monitored for breast and uterine cancer (pelvic exam, breast exam, mammogram) at least yearly.
• Caution patient that cigarette smoking, high BP, high cholesterol, diabetes, and being overweight during estrogen therapy may increase risk of heart disease.
• Ospemifene should not be taken during pregnancy. Instruct patient to notify health care professional immediately if pregnancy is planned or suspected or if breast feeding.
• Advise patient to discuss dose and need for ospemifene every 3–6 mo.

Evaluation/Desired Outcomes

Decrease in pain during intercourse.