This medication is used in men who do not make enough of a natural substance called testosterone. In males, testosterone is responsible for many normal functions, including growth and development of the genitals, muscles, and bones. It also helps cause normal sexual development (puberty) in boys. Fluoxymesterone is similar to the natural testosterone produced by your body. It belongs to a class of drugs known as androgens. It works by affecting many body systems so that the body can develop and function normally.
Fluoxymesterone may also be used in certain adolescent boys to cause puberty in those with delayed puberty.
Take this medication by mouth with or without food, usually 1 to 4 times a day, as directed by your doctor.
Dosage is based on your medical condition, testosterone blood levels, and response to treatment.
Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same times each day.
Do not suddenly stop using fluoxymesterone if you have been using it regularly for an extended time or if it has been used in high doses. In such cases, your body will no longer make its own testosterone, and withdrawal reactions (such as tiredness, weakness, depression) may occur. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately.
Abnormal drug-seeking behavior is possible with this medication, and it is frequently misused for its muscle-enhancing effects. Do not increase your dose, take it more frequently, or take it for a longer time than prescribed. Doing so may increase serious side effects (such as increased risk for heart disease, stroke, liver disease, ruptured tendons/ligaments, improper bone development in adolescents). Properly stop the medication when so directed.
Tell your doctor if your condition does not improve or worsens.
Nausea, vomiting, headache, skin color changes, increased/decreased sexual interest, oily skin, hair loss, and acne may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects when it is used at normal doses.
If you are male, tell your doctor immediately if any of these unlikely but serious side effects occur: trouble urinating, breast swelling/tenderness, too frequent/prolonged erections.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and seek immediate medical attention, or permanent problems could occur.
If you are female, tell your doctor immediately if any of these unlikely but serious side effects occur: deepening of the voice, hoarseness, unusual facial/body hair growth, enlarged clitoris, irregular menstrual periods.
This medication can cause your body to hold on to extra body water (edema). This can increase your risk of heart failure. Tell your doctor immediately if any of these unlikely but serious signs of water retention or heart failure occur: decreased exercise ability, hands/ankles/feet swelling, unusual tiredness, shortness of breath while lying down.
Tell your doctor immediately if any of these rare but very serious side effects occur: signs of serious liver disease (such as persistent abdominal pain/nausea, unusual tiredness, yellowing eyes/skin, dark urine).
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
In the US -
Before taking fluoxymesterone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart disease (such as heart failure, chest pain, heart attack), liver problems, kidney problems, other types of cancer, certain mineral imbalance (high calcium blood level), high cholesterol, high blood pressure, enlarged prostate, breathing problems (such as sleep apnea, chronic obstructive pulmonary disease-COPD), diabetes.
If you have diabetes, this product may decrease your blood sugar levels. Check your blood sugar levels regularly as directed by your doctor. Tell your doctor immediately if you have symptoms of low blood sugar, such as increased hunger, dizziness, or unusual sweating. Your anti-diabetic medication or diet may need to be adjusted.
This drug may affect your cholesterol and may increase your risk of heart or blood vessel problems (coronary artery disease). Your doctor will monitor your cholesterol level closely.
Tell your doctor if you become bed-ridden (unable to walk) for a prolonged time while using this medication. Your doctor may monitor your blood calcium level to prevent problems.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Caution is advised when using this drug in older adults because they may be at greater risk for prostate/liver problems and swelling of arms/legs.
Caution is advised when using this drug in children because bone growth may be affected, causing shorter adult height. Your child's doctor will monitor growth and bone development during treatment.
This medication must not be used during pregnancy. It may harm an unborn baby. Discuss the use of reliable forms of birth control (such as condoms, birth control pills) with your doctor. If you become pregnant or think you may be pregnant, tell your doctor immediately.
It is not known whether this drug passes into breast milk. It may affect milk production and it may harm a nursing infant. Breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: "blood thinners" (such as warfarin).
Corticosteroids (such as hydrocortisone, prednisone) may increase the risk of edema and heart failure.
This medication may interfere with certain laboratory tests (including thyroid function tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share or sell this medication to others. It is against the law.
Laboratory and/or medical tests (such as blood testosterone levels, red blood cell counts, liver function tests, blood cholesterol levels, PSA test) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature at 59-86 degrees F (15-30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
Information last revised December 2014. Copyright(c) 2014 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet