Letrozole prevents or suppresses the adrenal glands from producing oestrogen (which may cause the growth of some types of breast cancer) without affecting the production of other steroid hormones produced by these glands.
Letrozole is licensed for the treatment of localised breast cancer or metastatic in women who have not menstruated.
There are unlicensed uses of Letrozole pills such as
- Letrozole is prescribed to treat infertility in both males and females.
- Bodybuilders take Letrozole pills to counteract the estrogenic effects of steroid drugs.
- Letrozole may be taken in combination with misoprostol for early medical abortion.
In general, Letrozole tablets can be prescribed to patients when the therapeutic goal is to reduce the levels of oestrogen in the body.
Composition
- Active substance: Letrozole.
- Each film-coated tablet contains 2.5 mg letrozole.
Therapeutic indications
Adjuvant treatment of postmenopausal women with hormone receptor positive invasive early breast cancer.
Extended adjuvant treatment of hormone-dependent invasive breast cancer in postmenopausal women who have received prior standard adjuvant tamoxifen therapy for 5 years.
First-line treatment in postmenopausal women with hormone-dependent
advanced breast cancer.
Advanced breast cancer after relapse or disease progression, in women with natural or artificially induced postmenopausal endocrine status, who have previously been treated with anti-oestrogens .
Neo-adjuvant treatment of postmenopausal women with hormone receptor positive.HER-2 negative breast cancer where chemotherapy is not suitable and imme diate surgery not indicated.
Efficacy has not been demonstrated in patients with hormone receptor negative breast cancer.
Posology and method of administration
Adult and elderly patients
the recommended dose of Letrozole is 2.5 mg once daily. No dose adjustment is required for elderly patients.
in patients with advanced or metastatic breast cancer, treatment with Letrozole should continue until tumour progression is evident.
in the adjuvant and extended adjuvant setting, treatment with Letrozole should continue for 5 years or until tumour relapse occurs, whichever is first.
in the adjuvant setting a sequential treatment schedule Letrozole 2 years followed by tamoxifen 3 years could also be considered .
in the neoadjuvant setting treatment with Letrozole could be continued for 4 to 8 months in order to establish optimal tumour reduction.
if the response is not ad equate, treatment with Letrozole should be discontinued and surgery scheduled and/or further treatment options discussed with the patient.
Paediatric population
Letrozole is not recommended for use in children and adolescents. The safety and efficacy of Letrozole in children and adolescents aged up to 17 years have not been established. Limited data are available and no recommendation on a posology can be made.
Renal impairment
No dosage adjustment of Letrozole is required for patients with renal insufficiency with creatinine clearance ≥10 ml/min.
Insufficient data are available in cases of renal insufficiency with creatinine clearance lower than 10 ml/min .
Hepatic impairment
No dose adjustment of Letrozole is required for patients with mild to moderate hepatic insufficiency .
Insufficient data are available for patients with severe hepatic impairment. Patients with severe hepatic impairment require close supervision.
Method of administration
Letrozole should be taken orally and can be taken with or without food.
The missed dose should be taken as soon as the patient remembers. However, if it is almost time for the next dose (within 2 or 3 hours), the missed dose should be skipped, and the patient should go back to her regular dosage schedule. Doses should not be doubled because with daily doses over the 2.5 mg recommended dose, over-proportionality in systemic exposure was observed .
Undesirable effects
Common side effects include:
- Hypercholesterolaemia.
- Anorexia, appetite increase.
- Depression
- Headache, dizziness
- Hot flushes
- Hypertension
- Nausea, dyspepsia, constipation, abdominal pain, diarrhoea, vomiting.
- Increased sweating
- Alopecia, rash (including erythematous, maculopapular, psoriaform, and
vesicular rash), dry skin - Arthralgia
- Myalgia, bone pain, osteoporosis, bone fractures.
- Vaginal bleeding
- Fatigue (including asthenia, malaise)
- Weight increase.
Letrozole – Frequently Asked Questions
Q.1- I take psychiatric medications and antidepressants, and these medications caused me to have an enlarged breast (gynecomastia)? Are Letrozole pills useful in the treatment of gynecomastia caused by psychological and neurological drugs?
Indeed, some psychiatric medications and antidepressants can lead to an increase in estrogen and prolactin levels, causing the breasts to enlarge in men (a condition known as gynecomastia).
On the other hand, psychiatric drugs and antidepressants may cause a general increase in weight. This happens to some people after three to four months of taking the drug, and in such a case (i.e. general weight gain) it may result in some accumulation of fat in the breast area, and this may give a feeling of protrusion or enlargement of the breasts.
Letrozole is a hormonal drug, and it is never recommended to take it unless it is prescribed by your doctor. It is even necessary for the patient to take Letrozole under medical supervision throughout the treatment period with Letrozole pills.
I advise you, do not take Letrozole (to inhibit the production of estrogen) on your own. If there is any need to use Letrozole pills, it must be under medical supervision.
Q.2- Is Letrozole prescribed to treat delayed childbearing in women?
Yes, the doctor can prescribe Letrozole pills to stimulate ovulation (the production of eggs from the ovary).
Letrozole pills are often prescribed with Fostimon injections. Usually, doctors prescribe Letrozole to stimulate ovulation in cases that suffer from imbalances in the levels of hormones (LH, and FSH) and after the doctor has started to activate it with Clomid pills.
Q.3- Why do bodybuilders use Letrozole pills?
Letrozole pills are prescribed during a course of muscle bulking and toning to protect against estrogenic side effects caused by steroids, and can be prescribed after the course to help increase the secretion of natural testosterone. The usual dose is half to 1 tablet, once daily.
When using anabolic steroids, part of it is converted by an enzyme called aromatase into estrogen, which leads to many undesirable estrogenic side effects such as: breast enlargement, water retention in the body, oily skin and acne.
Letrozole pills are pills that block or inhibit the action of the aromatase enzyme, thus preventing the accumulation of estrogen in the body, thus reducing unwanted estrogenic side effects, and helping to maintain the benefits gained from the steroid courses.
You should know that Letrozole pills are not authorised to be used in this case, and Letrozole or any other treatment courses should not be taken by bodybuilders without consulting the doctor.
Important disclaimer: Decreased levels of estrogen, below the normal range, in men, will lead to osteoporosis, erectile dysfunction, and loss of sexual desire.
Q.4- Does Letrozole treat male infertility?
Andrologists and infertility doctors can prescribe Letrozole pills for men who suffer from infertility due to a low number or low production of sperm.
In about 22% of male infertility cases, the causes are unknown with the absence of any lesions such as varicose veins, and these cases are characterized by a moderate or severe deficiency in Normal sperm count, motility and shape.
It is medically known that the male hormone (testosterone) is converted in the body, especially in fat cells, into a female hormone (estrogen) by an enzyme called aromatase. High levels of estrogen in a man’s body negatively affect sperm production from the testicles.
Letrozole pills stop the action of the aromatase enzyme, thus helping to reduce estrogen levels and raise testosterone levels, which leads to activating the process of spermatogenesis (sperm production) and increasing their number and movement.
Letrozole pills can be prescribed to men to treat infertility of unknown cause, which is characterized by a decrease in the number and movement of sperm.
Letrozole is often prescribed, in such cases, with other drugs., such as antioxidants and other stimulants and nutritional supplements.
Important tip: Do not take this medicine on your own without checking with your doctor. It may harm your health if you use the medicine for no justified reason or in the wrong doses.
Q.5 – How does Letrozole work?
The body’s production of estrogen is through a number of biological processes, the last stage in the process of estrogen synthesis is carried out with the help of an enzyme called (the aromatase enzyme). Letrozole pills block or stop the action of this enzyme, thus limiting or preventing the body’s production of estrogen.
Certain types of breast cancer are associated with increased levels of estrogen, therefore, reducing estrogen production with Letrozole pills prevents the development of a tumor.
Letrozole tablets are intended for the treatment of breast cancer in postmenopausal women only.
The aromatase enzyme participates in the production of (estrogen) the female sex hormone in women who have entered menopause, and Letrozole tablets prevent the action of the aromatase enzyme. This leads to a decrease in estrogen levels.
Most breast cancers are sensitive to estrogen, meaning that estrogen stimulates the growth of this cancerous tumor, and by reducing estrogen levels in the body, this prevents the tumor from growing or spreading.
Letrozole tablets are only effective in treating breast cancers that are sensitive to estrogen.
Precautions and warnings
Blood clots
n rare cases, Letrozole tablets can cause blood clots, so it is recommended to inform the doctor immediately if you feel pain in the lower legs, redness and swelling in the arms or legs, chest pain, or difficulty and shortness of breath .
Hair loss
arely, Letrozolee pills can also cause hair loss. Usually, the hair that is falling out returns to growth once the treatment is finished, it may grow in a different colour or structure than the previous one.
I advise you to do the following in order to maintain your hair during the treatment period with Letrozole pills:
- avoid using hairspray, dyes, or any chemical hair care products.
- You should also wear hats or something similar to protect the scalp from weather factors, especially direct sunlight and extreme cold.
Hypercholesterolemia
Letrozole pills increase the levels of blood fats, so it is recommended to have a periodic blood test for “cholesterol level”, and the doctor must take this into account, especially during long-term treatment periods.
Hypertesion
Letrozole pills may increase or raise blood pressure and change the heart rhythm (causing an acceleration of the heartbeat), so it is recommended to check your blood pressure periodically.
Fatigue & dizziness
Letrozole tablets, may cause fatigue and dizziness, so care should be taken when engaging in potentially hazardous activities, such as driving or operating machinery, and do not engage in these activities until you know how Letrozole tablets affect you, and until you are sure that you can perform these activities properly.
Decline in Bone strength – Osteoporosis
Estrogen helps protect bone strength. After menopause, estrogen levels naturally decline at this age, and this can cause your bones to become weaker, and since Letrozole tablets also reduce estrogen levels, it may lead to a further weakening of bone strength. Therefore, your doctor may prescribe another medicine for you, along with Letrozole, to help protect your bones.
Cautions in Special population
Letrozole should be used with caution in the following cases:
- People with severely reduced kidney or liver function.
- People with osteoporosis or at risk of developing osteoporosis.
Contraindication
Letrozole should not be used in the following cases:
- Women who have not yet reached menopause.
- Pregnant or breastfeeding women.
Product reference code: L02BG04.