Breast cancer is one of the most widespread and important diseases in the world, and it is considered one of the biggest medical and public health challenges. This disease, which in recent years has caused deep concerns in the global community with the increase in incidence and mortality related to it, needs new and effective treatments. Letrozole, as an inhibitor of estrogen production in the body, is of great importance in the treatment of breast cancer. This drug reduces the growth and spread of cancer cells by reducing the level of estrogen in the body. This practical mechanism is very important and effective in reducing the risks and treating breast cancer.
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Pharmaceutical forms of letrozole
Letrozole drug is produced and marketed in the form of 2.5 mg tablets. Its related drugs include pembrolizumab, aberlix, goserelin, hysterlin, leuprorelin, triptorelin, everolimus, abmaciclib, tormifen, tocitumumab, trabectedin, trastuzumab, vinblastine, vincristine, vindesin, axitinib, alemtuzumab, anastrozole, etc.
Uses of letrozole tablets
This drug is used to treat certain types of breast cancer (such as hormone receptor-positive breast cancer) in postmenopausal women. Letrozole is also used to help prevent cancer from coming back. Some breast cancers are accelerated by the natural hormone estrogen. This drug reduces the amount of estrogen the body makes and helps slow or reverse the growth of these breast cancers. The most important uses of this drug are ovarian epithelial cancer (off-label) and breast cancer.
Pharmacological effects and mechanism of action of letrozole drug
Aromatase Inhibitor – By binding to the heme group of the aromatase enzyme, it blocks the conversion of androgens to estrogens, which in turn inhibits its activity. Metabolism of this drug takes place through 4,4′-methanol-bisbenzonitrile through the activity of CYP3A4 and 2A6. Inhibited aromatase enzymes and 90% excretion through urine.
Dosage of letrozole
Before taking letrozole, read the drug information on the drug package. The manufacturer of the drug has stated the amount and time of use of this drug for general use. Take this medication orally with or without food as directed by your doctor, usually once a day. Dosage is based on your medical condition and response to treatment. Since letrozole can be absorbed through the skin and lungs, pregnant women should not use this medicine or inhale dust from the tablets.
Time to take letrozole tablets
In addition to adults, letrozole is also used in children and the elderly, but its use and uses are more common in adults (because breast cancer is more common in adults and the elderly). The time to use this medicine is determined by the doctor by examining and performing various tests. By examining the tests, the type of disease or inflammation, the patient’s age, etc., the doctor determines the appropriate time and amount of medication for the patient so that we can see the least side effects along with the treatment.
Precautions
Before taking letrozole, if you are allergic to this drug or anastrozole, avoid taking it. This drug may contain inactive ingredients that can cause allergic reactions or other problems. Before using this medication, your medical history, including high blood fat (cholesterol), bone problems (such as osteoporosis, osteoporosis), stroke or blood clots, heart disease (such as chest pain, heart attack, heart failure ), tell your doctor about high blood pressure, kidney problems, liver problems, etc., so that the doctor can prescribe a prescription based on that.
- Patients, before using letrozole, read the drug information on its package. The manufacturer has provided sufficient information regarding the precautions and contraindications of this drug. If you have any of these cautions, stop taking the medicine and see a doctor.
- Be careful in liver failure. prescribing a low dose for patients with liver failure; The effect of liver failure on drug exposure in cancer patients with high bilirubin levels has not been determined.
- A decrease in bone mineral density may occur. Consider monitoring bone mineral density.
- Taking this medicine may cause dizziness, drowsiness and fatigue. Be careful when operating machinery or driving.
- This medicine increases serum total cholesterol in some patients. Consider cholesterol monitoring.
- The dosage and amount of this medicine is very different for patients. Consult your doctor about how to use it and the risks of using it. If necessary, advise the doctor (in the case of special medical records) to change the drug and use similar drugs.
- If you forget to take a dose of letrozole, take the missed dose immediately, unless it is less than 3 hours before the next dose. In this case, do not take the missed dose and take the previous dose as usual.
- Before taking any medicine, check the expiration date so that the medicine has not spoiled. If the medicine expires, dispose of it according to hygiene principles.
Letrozole contraindications
Letrozole may make you dizzy or tired, or rarely blur your vision. Avoid alcohol or marijuana, as it can cause dizziness or extreme fatigue. Until you regain full consciousness, driving, working with machines, tools, etc. is prohibited. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, over-the-counter drugs, and herbal products). This medicine should not be used during pregnancy, because it causes damage to the fetus.
- Allergy to drugs or excipients
- Pregnancy, premenopausal women
side effects of letrozole
Hot flashes, hair loss, bone pain, fatigue, unusual sweating, nausea, diarrhea, dizziness and sleep problems are some of the side effects of letrozole. If any of these effects persist or worsen, tell your doctor or pharmacist right away. Remember that this medication has been prescribed because your doctor has determined that the benefits to you are greater than the risk of side effects. Most people who use this drug do not experience serious side effects. Some of the serious side effects of bone fracture, pain or swelling of joints, muscles and tendons, mental and emotional changes (such as depression, anxiety), swelling of arms and legs, blurred vision, unusual fatigue, dark urine, yellowing of the eyes and skin, etc. be
In case of sudden shortness of breath, pain in the chest, jaw or left arm, confusion, coughing up blood, sudden dizziness or fainting, pain, swelling and warmth in the groin or leg, tingling, weakness and numbness in the arms or legs. , difficulty speaking, weakness on one side of the body, changes in vision, sudden or severe headache, etc. Stop taking the medicine and see a doctor. Also, a very serious allergic reaction to this drug is rare. However, if you notice any signs of a serious allergic reaction, including skin rash, itching or swelling (especially of the face, tongue, throat, and neck), severe dizziness, trouble breathing, etc., see a doctor right away.
- Diaphoresis
- Bone pain and back pain
- hot flashes
- nausea
- Night sweats and shortness of breath
- Cough and fatigue
- Constipation or diarrhea
- High blood pressure or chest pain
- Weight Loss
- human
- chest pain
- Bone fracture
- Hypercalcemia
- Headache and weakness
- Vomit
- Osteoporosis and bone fractures
Letrozole drug interactions
Drug interactions may change how your medications work or increase your risk of serious side effects. Patients, before visiting the doctor, prepare a list of chemical and herbal medicines you use and show them to him. Do not start, stop, or change any medication without your doctor’s approval. Estrogen drugs (such as ethinyl estradiol, conjugated estrogens), estrogen blockers (such as anastrozole, tamoxifen), tibolone, etc., according to some reports, will cause drug interactions with letrozole. However, this drug has a limited drug interaction regarding its mechanism of action.
- Class X interactions (avoid): estrogens (eg, ethinyl estradiol, conjugated estrogens), estrogen blockers (eg, anastrozole, tamoxifen), tibolone
- Reduction of the effects of letrozole by drugs: tamoxifen
- Enhancement of drug effects by letrozole: methadone, levomethadone, nintedanib
Taking letrozole during pregnancy and breastfeeding
Based on post-marketing reports, animal study findings and mechanism of action, the treatment can cause fetal harm and is contraindicated for use in pregnant women. In post-marketing reports, use during pregnancy has resulted in spontaneous abortions and birth defects. However, the data are not sufficient to inform the risk associated with the drug. Also advise women of childbearing potential to use effective contraception during treatment and for at least 3 weeks after the last dose. Treatment may impair fertility in women and men of childbearing potential.
The effect of letrozole on breastfeeding
It is not yet known whether this drug is present in human milk, and there is no information on the effects on nursing infants or breast milk production. Exposure of lactating rats to the drug was associated with impaired reproductive performance of male offspring. Because of the potential for serious adverse reactions in breastfed infants, advise nursing women not to breastfeed while receiving treatment and for at least 3 weeks after the last dose.
Letrozole storage conditions
Letrozole should be stored at room temperature and away from light and moisture. Also, all chemical and herbal medicines should be kept out of the reach of children and animals.
The last word of letrozole drug
As we explained in this article from Positive Green Online Pharmacy magazine, letrozole drug has caused positive and visible changes in the treatment of breast cancer and has helped to improve the living conditions of patients and increase the survival rate. Optimal use of this drug is important not only for breast cancer patients, but also for doctors and researchers in the field of breast cancer. As an important innovation in the treatment of breast cancer, letrozole has saved a significant number of lives and ensured the improvement of the living conditions of patients and their families.
Site source: Medscape