How does this medication work? What will it do for me?

Medroxyprogesterone belongs to the family of medications known as progestins. Progestins are female hormones. They are produced by the body and are necessary along with other hormones for normal female sexual development and for the regulation of the menstrual cycle during childbearing years. Medroxyprogesterone reduces the effects of estrogen on tissues such as the endometrium (lining of the uterus) and the breast.

Medroxyprogesterone has a variety of uses. It is used in addition to postmenopausal estrogen replacement therapy (ERT) to prevent estrogen from thickening the lining of the uterus (endometrial hyperplasia). This significantly reduces the risk of endometrial cancer. It is also used to treat irregular menstrual cycles, lack of menstruation, and abnormal menstrual bleeding. Medroxyprogesterone is also used alone or in combination with other cancer medications to treat endometrial cancer and breast cancer.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

2.5 mg
Each round, pink-orange, biconvex tablet scored and marked "MED" over "2.5" on one side and "APO" on the other, contains 2.5 mg medroxyprogesterone acetate. Nonmedicinal ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate, sodium lauryl sulfate and colloidal silicon dioxide, D&C Yellow No. 10, and FD&C Yellow No. 6.

5 mg
Each round, blue, biconvex tablet scored and marked "MED" over "5" on one side and "APO" on the other, contains 5 mg medroxyprogesterone acetate. Nonmedicinal ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate, sodium lauryl sulfate and colloidal silicon dioxide, and FD&C Blue No. 2.

10 mg
Each round, white, biconvex tablet scored and marked "APO" over "10" on one side and plain on the other, contains 10 mg medroxyprogesterone acetate. Nonmedicinal ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate, sodium lauryl sulfate, and colloidal silicon dioxide.

100 mg
Each round, white, bevelled-edged tablet, scored and marked "MED" over "100" on one side and "APO" on the other, contains 100 mg medroxyprogesterone acetate. Nonmedicinal ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate, sodium lauryl sulfate, and colloidal silicon dioxide.

How should I use this medication?

The recommended adult dose of medroxyprogesterone varies widely and depends on the condition being treated and the response to treatment.

For hormone replacement therapy, the dose ranges from 2.5 mg daily to 10 mg daily for several specific days of the month.

To control unusual and heavy bleeding of the uterus, or for treating unusual stopping of menstrual periods, a typical dose of medroxyprogesterone is 5 mg to 10 mg daily for 10 to 14 days per month.

A typical dose to treat breast cancer is 400 mg daily, and a typical dose for endometrial cancer treatment is 200 mg to 400 mg daily.

Medroxyprogesterone may be taken with or without food.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Unless medroxyprogesterone is being taken as part of breast cancer treatment, this medication should not be taken by women without an intact uterus.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose of medroxyprogesterone and it is within 12 hours of the missed dose, take it as soon as you remember. If it is more than 12 hours since the missed dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication in a dry place at room temperature, out of direct light, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to medroxyprogesterone or any ingredients of the medication
  • are or may be pregnant
  • have certain blood clotting disorders or a history of these disorders (thrombophlebitis, thromboembolic disorders, stroke)
  • have known or suspected cancer dependent on hormones for growth (e.g. endometrial cancer)
  • have liver disease
  • have loss of vision due to disease of the blood vessels of the eyes
  • have or have had breast cancer
  • have undiagnosed abnormal vaginal bleeding

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • acne
  • breast pain or tenderness
  • changes in the amount of body, facial, or scalp hair
  • changes in menstruation (i.e., heavier bleeding, lack of menstrual bleeding, spotting between menstrual periods)
  • dizziness
  • fatigue
  • headache
  • itchiness
  • mild blood pressure increase
  • mild headache
  • nausea
  • nervousness
  • pain or swelling in abdomen
  • premenstrual syndrome-like symptoms (e.g., irritability, bloating, emotional changes)
  • sleeping problems
  • swelling or a bloated feeling of the face, ankles, or feet
  • unusual or rapid weight gain
  • unexpected vaginal discharge

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • breast lump
  • changes in vaginal bleeding
  • increased flow of breast milk
  • moon-shaped face
  • signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
  • signs of  liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • skin rash
  • symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • chest pain
  • seizures
  • signs of a blood clot in blood vessels, such as sudden vision change or dizziness, chest pain, pain and swelling in one leg muscle
  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
  • signs of stroke (e.g., sudden headache, weakness or numbness in an arm or leg, difficulty speaking or understanding, sudden vision difficulty, dizziness)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Important information about estrogen and progesterone:

  • This medication should be used at the lowest dose that relieves your menopausal symptoms for the shortest time period possible.
  • You should not use estrogens with or without progestins to prevent heart disease, heart attacks, or strokes.

Many of these warnings apply to medroxyprogesterone because it is often taken with estrogen. It is not clear whether they are as likely to occur if medroxyprogesterone is taken alone or with medications to treat cancer. People taking this medication to treat cancer should discuss the risks and benefits of progestins with their doctor.

Bleeding: Withdrawal bleeding usually occurs within 7 days of stopping medroxyprogesterone. If you experience vaginal bleeding on the days you are taking this medication, contact your doctor.

Blood clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities.

If you have a history of clotting, you may be at increased risk of experiencing blood-clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision, or difficulty speaking, contact your doctor immediately.

Breast disease: Certain types of breast disease (e.g., lumps or cysts) can be made worse by this medication. If you have a history of breast disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Breathing problems: Medroxyprogesterone can cause a build-up of fluid in the body, leading to difficulty breathing. If you have asthma or other breathing problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Dementia: Women over the age of 65 receiving combined hormone replacement therapy (estrogen and progestin) may be at increased risk of developing dementia (loss of memory and intellectual function). If you are over 65, talk to your doctor about whether you should be tested for dementia.

Depression: Hormones, such as estrogen and progesterone, have been known to cause mood swings and symptoms of depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, and decreased interest in activities, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.

Diabetes: Medroxyprogesterone may cause an increase in blood sugar levels, and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication. If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart disease: This medication may cause an increase in the fluid retained by the body. This can increase the risk of problems if you have heart disease. If you have heart disease, such as congestive heart failure, or high blood pressure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: This medication may cause an increase in the fluid retained by the body. This increased amount of fluid in the body can increase the stress on the kidneys. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Migraine: Hormone therapy can sometimes cause migraine headaches. If you experience migraines or have a history of migraines, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience unusual headaches, possibly affecting one side of the head, which may or may not have visual symptoms, contact your doctor as soon as possible.

Seizures: Hormone therapy may cause an increase in the frequency of seizures for someone with seizure disorder. If you have a history of epilepsy or medical conditions that increase your risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: Women should use effective birth control when taking this medication. If you become pregnant while taking medroxyprogesterone, contact your doctor immediately.

Breast-feeding: Medroxyprogesterone does pass into breast milk, but it has not been associated with harmful effects in breast-fed infants. If you have concerns about continuing to breast-feed while taking this medication, talk to your doctor.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between medroxyprogesterone acetate and any of the following:

  • abiraterone
  • acitretin
  • alitretinoin
  • amiodarone
  • apixaban
  • aprepitant
  • aripiprazole
  • boceprevir
  • bosentan
  • calcium channel blockers (e.g., diltiazem, nifedipine, verapamil)
  • cholestyramine
  • clobazam
  • colestipol
  • cyclosporine
  • dabigatran
  • deferasirox
  • dexamethasone
  • diabetes medications (e.g., chlorpropamide, glipizide, glyburide, insulin, metformin, nateglinide, rosiglitazone)
  • heparin
  • low molecular weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
  • HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delaviridine, efavirenz, etravirine, nevirapine)
  • HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
  • hydrocodone
  • isotretinoin
  • macrolide antibiotics (e.g., clarithromycin, erythromycin)
  • metronidazole
  • mifepristone
  • mitotane
  • modafinil
  • mycophenolate
  • norfloxacin
  • oxcarbazepine
  • perampanel
  • prucalopride
  • rifabutin
  • rifampin
  • rivaroxaban
  • St. John's wort
  • seizure medications (e.g., carbamazepine, clobazam, ethosuximide, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
  • selegiline
  • tetracycline
  • thalidomide
  • tocilizumab
  • tranexamic acid
  • tretinoin
  • tyrosine kinase inhibitors (e.g., dabrafenib, crizotinib, imatinib)
  • ulipristal
  • voriconazole
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.