Ospemifene

Before taking ospemifene,

• tell your doctor and pharmacist if you are allergic to ospemifene or any of the ingredients in ospemifene tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: antifungals such as itraconazole (Sporanox), fluconazole (Diflucan), ketoconazole (Nizoral);clarithromycin (Biaxin); estrogens such as (Premarin); estrogen agonists/antagonists such as tamoxifen (Nolvadex); medications for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) such as indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), saquinavir (Fortovase, Invirase); nefazodone; or rifampin (Rifadin, Rimactane, in Rifamate). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. Ospemifene may cause fetal harm. If you become pregnant while taking ospemifene, call your doctor immediately.
• if you are having surgery, including dental surgery, tell the doctor or dentist you are taking ospemifene.

Ospemifene may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• hot flashes or flushes
• vaginal discharge
• muscle spasms
• increased sweating

Some side effects can be serious. f you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

• changes in vision
• slow or difficult speech
• sudden severe headache
• pain in your chest or legs with or without shortness of breath, weakness, and fatigue

Ospemifene may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

You should not use ospemifene together with estrogens, such as birth control pills or hormone replacement medications.

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with ospemifene, especially:

• fluconazole.

This list is not complete. Other drugs may interact with ospemifene, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

1-10%

Hot flush (7.5%)

Vaginal discharge (3.8%)

Muscle spasms (3.2%)

Hyperhidrosis (1.6%)

Genital discharge (1.3%)

Postmarketing reports

Hypersensitivity

Angioedema

Rash

Rash, erythematous

Generalized rash

Pruritus

Urticaria

Ospemifene is a prescription medication used to treat painful sexual intercourse caused by changes in the tissues in the vagina due to menopause. 

Ospemifene belongs to a group of drugs called estrogen agonist/antagonists. Although it is not an estrogen, it works by binding to estrogen receptors in some tissues and blocking estrogenic pathways in others. 

This medication comes in tablet form. It is taken once daily, with food. 

Common side effects include hot flashes, vaginal discharge, muscle spasms, and increased sweating.

Tell your doctor about all the medicines you take including prescription and nonprescription medicines, vitamins and herbal supplements. Especially tell your doctor if you are taking:

• estrogens or estrogen agonist/antagonist such as estradiol (Estrace)
• fluconazole and ketoconazole
• rifampin 

This is not a complete list of ospemifene drug interactions. Ask your doctor or pharmacist for more information. 

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Ospemifene falls into category X. It has been shown that women taking ospemifene during pregnancy may have babies born with problems. There are no situations where the benefits of the medication for the mother outweighs the risks of harm to the baby. This medication should never by used by pregnant women. 

If you take too much ospemifene, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away. 

Do not use ospemifene if you are pregnant or may become pregnant.

You should not use this medication if you have unusual vaginal bleeding, breast or uterine cancer, or a history of heart attack, stroke, or blood clot.

Ospemifene may increase your risk of developing endometrial hyperplasia, a condition that may lead to cancer of the uterus. Report any unusual vaginal bleeding to your doctor right away.

Ospemifene may also increase your risk of a stroke or blood clot. Talk with your doctor about your individual risks.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

In the U.S.

• Osphena

Available Dosage Forms:

• Tablet

Therapeutic Class: Endocrine-Metabolic Agent

Pharmacologic Class: Selective Estrogen Receptor Modulator

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

It is unlikely that a postmenopausal woman may become pregnant. But you should know that using ospemifene while you are pregnant could harm your unborn baby. If you think you have become pregnant while using the medicine, tell your doctor right away.

Using ospemifene may increase your risk for blood clots, strokes, or heart attacks. Your risk for these serious problems is even greater if you have high blood pressure, high cholesterol, or diabetes, or are overweight or smoke tobacco. Talk to your doctor about this risk. Contact your doctor right away if you have chest pain, confusion, difficulty speaking, double vision, headaches, an inability to move the arms, legs or facial muscle, or an inability to speak.

Using ospemifene may increase your risk for endometrial or uterine cancer. Talk to your doctor about this risk. Check with your doctor right away if you have abnormal vaginal bleeding.

Make sure any doctor who treats you knows that you are using ospemifene. You may need to stop using ospemifene before you have surgery or if you need to stay in bed for a long time.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Ospemifene is a selective estrogen receptor modulator (SERM); it activates estrogen pathways in some tissues and blocks estrogen pathways in others, and specifically has agonistic effects on the endometrium. In women with VVA, ospemifene was shown to improve vaginal changes associated with the decrease in natural estrogen production associated with menopause (improves vaginal maturation index, decreases vaginal pH) and significantly decreased the most bothersome moderate-to-severe subjective findings reported by women (vaginal dryness and dyspareunia) after 12 weeks of therapy (Bachmann, 2010).

Distribution

Vd: 448 L

Metabolism

Hepatic via CYP3A4, 2C9, and 2C19; forms a metabolite (4-hydroxyospemifene)

Excretion

Feces (75%); urine (7%; <0.2% as unchanged drug)

Dyspareunia, moderate-to-severe: Postmenopausal females: Oral: 60 mg once daily

1% to 10%:

Dermatologic: Hyperhidrosis (2%)

Endocrine & metabolic: Hot flash (8%)

Genitourinary: Proliferative endometrium (9%), endometrial hyperplasia (without atypia, 6%), vaginal discharge (4%), genital discharge (1%)

Neuromuscular & skeletal: Muscle spasm (3%)

<1% (Limited to important or life-threatening: Deep vein thrombosis, endometrial polyps, hemorrhagic stroke, hypersensitivity, thrombotic stroke