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. Methyltestosterone 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.
Methyltestosterone may also be used in certain adolescent boys to cause puberty in those with delayed puberty. It may also be used to treat certain types of breast cancer in women.
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 methyltestosterone 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 right away.
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.
Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as anxiety, depression, increased anger), trouble sleeping/snoring, signs of serious liver disease (such as persistent abdominal pain/nausea, unusual tiredness, yellowing eyes/skin, dark urine), hands/ankles/feet swelling, unusual tiredness, fast/irregular heartbeat.
Get medical help right away if you have any very serious side effects, including: shortness of breath/rapid breathing, chest/jaw/left arm pain, unusual sweating, confusion, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, sudden/severe headaches, trouble speaking, weakness on one side of the body, sudden vision changes.
If you are male, tell your doctor right away if you have any serious side effects, including: 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 get medical help right away, or permanent problems could occur.
If you are female, tell your doctor right away if you have any serious side effects, including: deepening of the voice, hoarseness, unusual facial/body hair growth, enlarged clitoris, irregular menstrual periods.
A very serious allergic reaction to this drug is rare. However, get medical help right away 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 using methyltestosterone, 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: cancer (such as breast cancer in men, prostate cancer), blood clots (such as in the leg, lungs), heart disease (such as heart failure, chest pain, heart attack), stroke, liver problems, kidney problems, 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 right away 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).
Older adults may be more sensitive to the side effects of this drug, especially prostate/liver problems, 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 right away.
It is unknown if 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.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: "blood thinners" (such as warfarin), cyclosporine.
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.
If overdose is suspected, contact a poison control center or emergency room right away. 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.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised June 2015. Copyright(c) 2015 First Databank, Inc.
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