Do NOT use Prometrium if:

• you are allergic to any ingredient in Prometrium or to peanuts
• you have a history of cancer of the breast, ovary, lining of the uterus, cervix, or vagina; vaginal bleeding of unknown cause; blood clots or clotting problems; or liver disease; you have had a recent miscarriage; or you have had a stroke or heart attack within the past year
• you are pregnant.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Prometrium. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have heart or blood vessel problems, bleeding problems, high blood pressure, high cholesterol or lipid levels, diabetes, kidney problems, asthma, migraine headaches, or lupus
• if you have a history of seizures, depression or other mental or mood problems, cancer, or tobacco use
• if you have a family history of blood clots
• if you are very overweight.

Some medicines may interact with Prometrium. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Rifampin because it may decrease Prometrium's effectiveness.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Prometrium may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Prometrium may cause drowsiness, dizziness, blurred vision, or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Prometrium with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• This product has peanut oil in it. Do not take Prometrium if you are allergic to peanuts.
• Diabetes patients - Prometrium may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
• Prometrium may increase your risk of developing blood clots. If you will be having surgery or be confined to a bed or chair for a long period of time (such as a long plane flight), notify your doctor beforehand. Special precautions may be needed in these circumstances while you are taking Prometrium.
• Prometrium may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Prometrium.
• Lab tests, including monthly breast self-exams, yearly breast exams, Pap smears, and pelvic exams, may be performed while you use Prometrium. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Prometrium should not be used in children; safety and effectiveness in children have not been confirmed.
• Pregnancy and breast-feeding: Do not use Prometrium if you are pregnant unless your doctor tells you otherwise. If you think you may be pregnant, contact your doctor. Prometrium is found in breast milk. If you are or will be breast-feeding while you use Prometrium, check with your doctor. Discuss any possible risks to your baby.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Bloating; breast tenderness; diarrhea; dizziness; drowsiness; dry mouth; fluid retention; headache; heartburn; irritability; muscle pain; nausea; stomach pain or cramping; tiredness; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); abnormal vaginal bleeding; bulging eyes; coughing up blood; dark urine; double vision; fainting; gallstones; mental or mood changes (eg, depression or worry); migraine; numbness of an arm or leg; pain or lumps in the breast; one-sided weakness; pounding in the chest; seizures or tremors; severe stomach pain; speech problems; stomach pain, swelling, or tenderness; sudden, severe chest pain or numbness; sudden, severe headache; sudden, severe vomiting, dizziness, or fainting; sudden sharp pain or swelling in the calf or leg; sudden shortness of breath; swelling of the ankles or fingers; vision problems or changes (including sudden, partial, or full loss of vision); yellowing of the eyes or skin.

 This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.