Medroxyprogesterone injection may decrease the amount of calcium stored in your bones. The longer you use this medication, the more the amount of calcium in your bones may decrease. The amount of calcium in your bones may not return to normal even after you stop using medroxyprogesterone injection.
Loss of calcium from your bones may cause osteoporosis (a condition in which the bones become thin and weak) and may increase the risk that your bones might break at some time in your life, especially after menopause (change of life).
The amount of calcium in the bones usually increases during the teenage years. A decrease in bone calcium during this important time of bone strengthening may be especially serious. It is not known whether your risk of developing osteoporosis later in life is greater if you start to use medroxyprogesterone injection when you are a teenager or young adult. Tell your doctor if you or anyone in your family has osteoporosis; if you have or have ever had any other bone disease or anorexia nervosa (an eating disorder); or if you drink a lot of alcohol or smoke a great deal. Tell your doctor if you take any of the following medications: corticosteroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), and prednisone (Deltasone); or medications for seizures such as carbamazepine (Tegretol), phenytoin (Dilantin), or phenobarbital (Luminal, Solfoton).
You should not use medroxyprogesterone injection for a long time (e.g., more than 2 years) unless no other method of birth control is right for you or no other medication will work to treat your condition. Your doctor may test your bones to be sure they are not becoming too thin before you continue to use medroxyprogesterone injection.
Keep all appointments with your doctor and the laboratory. Your doctor will monitor your health carefully to be sure you do not develop osteoporosis.
Talk to your doctor about the risks of using medroxyprogesterone injection.
Medroxyprogesterone intramuscular (into a muscle) injection and medroxyprogesterone subcutaneous (under the skin) injection are used to prevent pregnancy. Medroxyprogesterone subcutaneous injection is also used to treat endometriosis (a condition in which the type of tissue that lines the uterus (womb) grows in other areas of the body and causes pain, heavy or irregular menstruation [periods], and other symptoms). Medroxyprogesterone is in a class of medications called progestins. It works to prevent pregnancy by preventing ovulation (the release of eggs from the ovaries). Medroxyprogesterone also thins the lining of the uterus. This helps to prevent pregnancy in all women and slows the spread of tissue from the uterus to other parts of the body in women who have endometriosis. Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human immunodeficiency virus (HIV, the virus that causes acquired immunodeficiency syndrome [AIDS]) or other sexually transmitted diseases.
Medroxyprogesterone intramuscular injection comes as a suspension (liquid) to be injected into the buttocks or upper arm. It is usually given once every 3 months (13 weeks) by a healthcare provider in an office or clinic. Medroxyprogesterone subcutaneous injection comes as suspension to be injected just under the skin. It is usually injected once every 12 to 14 weeks by a healthcare provider in an office or clinic.
You must receive your first medroxyprogesterone subcutaneous or intramuscular injection only at a time when there is no possibility that you are pregnant. Therefore, you may only receive your first injection during the first 5 days of a normal menstrual period, during the first 5 days after you give birth if you are not planning to breast-feed your baby, or during the sixth week after giving birth if you are planning to breast-feed your baby. If you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor will tell you when you should receive your first injection.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Before using medroxyprogesterone injection,
You should eat plenty of foods that are rich in calcium and vitamin D while you are receiving medroxyprogesterone injection to help decrease the loss of calcium from your bones. Your doctor will tell you which foods are good sources of these nutrients and how many servings you need each day. Your doctor also may prescribe or recommend calcium or vitamin D supplements.
If you miss an appointment to receive an injection of medroxyprogesterone, call your doctor. You may not be protected from pregnancy if you do not receive your injections on schedule. If you do not receive an injection on schedule, your doctor will tell you when you should receive the missed injection. Your doctor will probably administer a pregnancy test to be sure that you are not pregnant before giving you the missed injection. You should use a different method of birth control, such as condoms until you receive the injection that you missed.
Medroxyprogesterone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Some side effects can be serious. The following side effects are uncommon, but if you experience any of them, call your doctor immediately:
If you are younger than 35 years old and began to receive medroxyprogesterone injection in the last 4 to 5 years, you may have a slightly increased risk that you will develop breast cancer. Medroxyprogesterone injection may also increase the chance that you will develop a blood clot that moves to your lungs or brain. Talk to your doctor about the risks of using this medication.
Medroxyprogesterone injection is a long-acting birth control method. You might not become pregnant for some time after you receive your last injection. Talk to your doctor about the effects of using this medication if you plan to become pregnant in the near future.
Medroxyprogesterone injection may cause other side effects. Call your doctor if you have any unusual problems while receiving 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 ( Web Site ) or by phone (1-800-332-1088).
Your doctor will store the medication in his or her office.
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at Web Site. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
You should have a complete physical exam, including blood pressure measurements, breast and pelvic exams, and a Pap test, at least yearly. Follow your doctor's directions for self-examining your breasts; report any lumps immediately.
Before you have any laboratory tests, tell the laboratory personnel that you are using medroxyprogesterone.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
¶ This branded product is no longer on the market. Generic alternatives may be available.
AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Last Reviewed: September 1, 2010.