Tamoxifen: functions, dosage, side effects, how to use it

What Drug Tamoxifen?

What is Tamoxifen for?

Tamoxifen is a drug with the function of treating breast cancer that has spread to other parts of the body (metastatic breast cancer), to treat breast cancer in certain patients after surgery and radiation therapy, and to reduce the chance of breast cancer in high-risk patients.

This drug can inhibit the growth of breast cancer. It works by interfering with the effects of estrogen on breast tissue.

Tamoxifen dosage and side effects of tamoxifen are detailed below.

How to use Tamoxifen?

Read the Medication Guide provided by your pharmacist before you start taking tamoxifen and each time you buy again. If you have any questions, consult your doctor or pharmacist.

This medication may be used before or after meals, usually once or twice daily for 5 years, or as directed by your doctor. Daily doses greater than 20 milligrams are usually halved and taken twice daily, morning and evening, or as directed by your doctor. If you are using a solution, measure the dose carefully with a measuring device or measuring spoon. Don't use a kitchen spoon because you may not get the correct dosage.

Dosage is based on your medical condition and your body's response to therapy.

Use this remedy regularly for best results. As a reminder, take the medication at the same time every day.

If you have breast cancer that has spread to other parts of the body, you will likely experience bone pain and pain in the cancerous area when you start taking tamoxifen. In some cases, this may mean a favorable response to drug use. Other symptoms such as increased bone pain, increased tumor size, or even a new tumor appears. These symptoms usually go away quickly. For whatever reason, report these symptoms to your doctor immediately.

Because this drug can be absorbed through the skin and lungs, women who are pregnant or will become pregnant should not use this medicine or inhale the powder from the tablets. (See also Warning section.)

Tell your doctor right away if your condition worsens (for example, you get a new lump in the breast).

How is Tamoxifen stored?

This medication is best stored at room temperature, away from direct light and damp places. Don't keep it in the bathroom. Don't freeze it. Other brands of this drug may have different storage rules. Observe the storage instructions on the product package or ask your pharmacist. Keep all medicines away from children and pets.

Do not flush medicines down the toilet or down the drain unless instructed to do so. Discard this product when it has expired or when it is no longer needed. Consult your pharmacist or local waste disposal company about how to safely dispose of your product.

Tamoxifen dosage

The information provided is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist before starting treatment.

What is the dosage of Tamoxifen for adults?

Usual Adult Dosage for Breast Cancer:

For the treatment of metastatic breast cancer in women and men:

20-40 mg orally and for doses greater than 20 mg should be given in divided doses (morning and evening).

For treatment of women with Ductal Carcinoma in Situ, after breast surgery and radiation:

20 mg taken daily for 5 years.

To reduce breast cancer in women who are at high risk of developing breast cancer:

20 mg taken daily for 5 years.

Usual Adult Dose for Breast Cancer - Adjuvants:

For the treatment of positive node breast cancer in postmenopausal women following total or segmental mastectomy, axillary dissection, and breast irradiation:

10 mg orally 2 to 3 times a day for 5 years.

Usual Adult Dosage for Breast Cancer - palliative:

10 to 20 mg taken by mouth twice a day

A favorable response may not be apparent for several months after starting therapy.

What is the dosage of Tamoxifen for children?

Usual Pediatric Dose for McCune-Albright Syndrome:

For use in girls 2 to 10 years of age with McCune-Albright Syndrome and precocious puberty:

20 mg once a day. The duration of treatment is up to 12 months.

Usual Pediatric Dose for Early Puberty:

For use in girls 2 to 10 years of age with McCune-Albright Syndrome and precocious puberty:

20 mg once a day. The duration of treatment is up to 12 months.

In what dosage is Tamoxifen available?

Solution, taken by mouth: 10 mg / 5 mL (150 mL)

Tablets: 10 mg; 20 mg

Tamoxifen side effects

What side effects can be experienced due to Tamoxifen?

Seek immediate medical help if you experience any of the following signs of an allergic reaction: hives, difficulty breathing, swelling of the face, lips, tongue, or throat.

Call your doctor right away if you have serious side effects such as:

• • sudden numbness, especially on one side of the body;
  • sudden severe headache, confusion, problems with vision, speech, or balance;
  • chest pain, sudden cough, wheezing, rapid breathing, rapid heart rate;
  • pain, swelling, warmth, or redness in one or both legs;
  • nausea, loss of appetite, increased thirst, muscle weakness, confusion, and feeling restless;
  • unusual vaginal bleeding;
  • irregular menstrual periods;
  • pelvic pain or pressure;
  • blurred vision, eye pain, or seeing halos around lights;
  • bruising easily, unusual bleeding (nose, mouth, vagina, or rectum), purple or red spots on the skin;
  • fever, chills, body aches, flu symptoms;
  • new breast lumps appear; or
  • upper abdominal pain, hives, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects include:

• • feeling hot;
  • bone pain, joint pain, or pain in the tumor;
  • swelling in the hands or feet;
  • vaginal itching or dryness;
  • decreased sex drive, impotence, or difficulty having an orgasm;
  • headache, dizziness, depression; or
  • thinning hair.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about side effects, please consult your doctor or pharmacist.

Medicines Tamoxifen Warnings and Cautions

What should be known before using Tamoxifen?

Pay attention and consider the risks of using drugs before use. The decision is made based on an agreement between you and your doctor. For this remedy, the following should be considered.

Allergy

Tell your doctor if you have any unusual or allergic reactions to this or any other medicine. Also tell your doctor if you have any other types of allergies such as to food, coloring, preservatives, or animal allergies. For over-the-counter products, read the labels on the packaging carefully.

Elderly

Many drugs have not been studied specifically in older people. Therefore, it may not be known whether they work in the same way as in young people. Although there is no specific information regarding the comparison of tamoxifen use in the elderly with use in other age groups, this drug is not expected to cause different side effects in the elderly and young people.

Is Tamoxifen safe for pregnant and lactating women?

There are no adequate studies regarding the risks of using this drug in pregnant or breastfeeding women. Always consult your doctor to weigh the potential benefits and risks before using this medication. This drug is included in the risk of pregnancy category C according to the US Food and Drug Administration (FDA).

The following references the pregnancy risk categories according to the FDA:

• A = No risk,
• B = not at risk in several studies,
• C = May be risky,
• D = There is positive evidence of risk,
• X = Contraindicated,
• N = Unknown

Tamoxifen Drug Interactions

What medicines may interact with Tamoxifen?

Although some drugs should not be taken at the same time, in other cases some drugs can also be used together even though interactions may occur. In such cases, the doctor may change the dose, or take other preventive measures as needed. Tell your doctor if you are taking any other over-the-counter or prescription drugs.

Taking this drug with any of the following medicines is not recommended. Your doctor may not prescribe this drug to you or will replace some of the drugs you are already taking.

• • Amifampridine
  • Fluconazole
  • Ketoconazole
  • Nelfinavir
  • Piperaquine
  • Posaconazole
  • Warfarin

Using this medication with some of the medicines below is not usually recommended, but in some cases it may be necessary. If both drugs are prescribed for you, your doctor will usually change the dosage or determine how often you should take them.

• • Abiraterone Acetate
  • Acenocoumarol
  • Anagrelide
  • Aprepitant
  • Aripiprazole
  • Buserelin
  • Carbamazepine
  • Ceritinib
  • Chlorpromazine
  • Clarithromycin
  • Clobazam
  • Cobicistat
  • Crizotinib
  • Cyclophosphamide
  • Dabrafenib
  • Delamanid
  • Desipramine
  • Deslorelin
  • Dicumarol
  • Domperidone
  • Escitalopram
  • Eslicarbazepine Acetate
  • Fluorouracil
  • Fluoxetine
  • Fluphenazine
  • Fluvoxamine
  • Fosaprepitant
  • Genistein
  • Gonadorelin
  • Goserelin
  • Histrelin
  • Idelalisib
  • Ipriflavone
  • Ivabradine
  • Leuprolide
  • Methotrexate
  • Metronidazole
  • Mitomycin
  • Mitotane
  • Moxifloxacin
  • Nafarelin
  • Nilotinib
  • Nitisinone
  • Ondansetron
  • Paroxetine
  • Pasireotide
  • Pazopanib
  • Phenprocoumon
  • Primidone
  • Quetiapine
  • Red Clover
  • Ritonavir
  • Sertraline
  • Sevofluran
  • Siltuximab
  • St John's Wort
  • Triptorelin
  • Vandetanib
  • Vemurafenib
  • Vinflunine

Taking this medication with the drugs below may increase your risk of side effects, but in some cases, a combination of these two drugs may be the best treatment. If both drugs are prescribed for you, your doctor will usually change the dosage or determine how often you should take them.

• • Aldesleukin
  • Aminoglutethimide
  • Anastrozole
  • Bexaroterie
  • Letrozole
  • Rifampin

Can food or alcohol interact with Tamoxifen?

Certain drugs should not be used with meals or when eating certain foods because drug interactions can occur. Consuming alcohol or tobacco with certain drugs can also cause interactions to occur. Discuss your use of drugs with food, alcohol, or tobacco with your health care provider.

What health conditions may interact with Tamoxifen?

Any other health conditions you have can affect the use of this drug. Always tell your doctor if you have other health problems, especially:

For all patients

• • Blood disorders
  • Cataracts or other eye problems. Tamoxifen can also cause this problem.
  • High cholesterol levels in the blood. Tamoxifen can increase cholesterol levels in the blood.

When used to reduce the risk of developing breast cancer in women at high risk or in women with ductal carcinoma in situation (DCIS):

• • Blood clots (or have had)
  • Pulmonary embolism (or having had)
  • Stroke
  • Uterine cancer, can increase the risk of serious side effects due to the use of tamoxifen.

Tamoxifen overdose

What should I do in an emergency or overdose?

In case of an emergency or overdose, contact the local emergency services provider (112) or immediately to the nearest hospital emergency department.

Symptoms of an overdose include:

• The body was shaking
• The body feels rocking
• Dizzy

What should I do if I miss a dose?

If you forget a dose of this medicine, take it as soon as possible. However, when it is nearing the time of the next dose, skip the missed dose and return to the usual dosing schedule. Don't double the dose.