For what purpose can the drug “Letrozole” be prescribed to the patient? Instructions for use of this medication are described in detail in this article. It also contains information about how much the medication mentioned costs, whether it has analogues, adverse reactions and contraindications, what patients say about it, etc.
Form, description, composition, packaging
What is included in the drug "Letrozole"? The medicine we are considering contains the same active substance. It also includes auxiliary components in the form of cellulose, lactose monohydrate, starch, sodium carboxymethyl starch, colloidal anhydrous silicon dioxide and magnesium stearate.
This medication goes on sale in the form of dark yellow film-coated tablets. They have a round and biconvex shape.
The drug "Letrozole", the price of which is indicated below, is sold in contour packs that are placed in packs of cardboard.
It should also be noted that, depending on the manufacturer, the medicine in question may have a different shape, packaging and packaging.
Pharmacodynamics of the drug
What features does the drug “Letrozole” have? Instructions for use states that it is an antitumor agent that inhibits the synthesis of estrogen.
This drug selectively inhibits aromatase, which is a very important biological enzyme for estrogen synthesis. This occurs due to the highly specific binding to elements of the enzyme.
According to studies, Letrozole is able to inhibit the estrogen biosynthesis in tumor and healthy peripheral tissues.
In the weaker sex in postmenopausal women, estrogens are formed with the direct participation of aromatase. It transforms androgens into estrone and estradiol, which occur in the adrenal glands.
Proper administration of the drug (0.1-5 mg per day) leads to a decrease in blood concentrations of estrone, estradiol and estrone sulfate by 95% of the initial content. In this case, the synthesis of estrogen should be suppressed throughout therapy.
Inhibition of estrogen synthesis increases the concentration of androgens, which, in fact, are the chemical precursors of estrogen.
What other features does the drug Letrozole have? The manufacturer claims that against the background of treatment with this agent, the incidence of osteoporosis is slightly increased.
Adjuvant treatment of the early stages of breast cancers significantly reduces the risk of relapse, and also increases 5-year survival without any visible signs of progress. Also, this medication reduces the likelihood of metastases and secondary tumors.
Long-term adjuvant therapy with this agent reduces the risk of relapse by about 42%.
Pharmacokinetics of the drug
Where is the absorption of the drug "Letrozole"? Instructions for use inform us that after oral administration, this medication is quite quickly and completely absorbed from the intestine. Its average bioavailability is 99.9%. In this case, eating significantly reduces the rate of absorption.
The time of onset of the highest concentration in the blood is 60 minutes when taking the medicine on an empty stomach and 120 minutes when taken together with food.
Communication with plasma proteins reaches about 60%. The accumulation of the active substance with prolonged use of the drug is not observed.
The metabolism of the drug occurs with the formation of an inactive metabolite. Its excretion is carried out with urine, as well as through the intestines. The half-life of the drug is 2 days.
Indications for use
For the treatment of what diseases do they use such medication as Letrozole? The reviews of experts say that the following diseases are indications for the use of this agent:
- Malignant neoplasms of the mammary gland in the early stages of the postmenopausal period after completion of the standard therapy with Tamoxifen (used as an additional prolonged treatment).
- Malignant neoplasms of the mammary gland in the early stages (tumor growth is stimulated by estrogens) in the weaker sex during the postmenopausal period (used as an additional treatment).
- Common malignant breast tumors in the postmenopausal period in people who have already received antiestrogen treatment.
- Common hormone-dependent forms of breast cancer in the postmenopausal period (first-line therapy).
Contraindications
Under what conditions should you not take Letrozole? Analogues of this medication and the drug itself is not recommended for patients with:
- hormonal status characteristic of the fertile period ;
- breastfeeding;
- sensitization to the main and additional substances of the drug;
- pregnancy
- in childhood.
It should also be noted that with special care this medication is used for lactase deficiency, lactose intolerance, as well as glucose-galactose malabsorption.
The drug "Letrozole": instructions for use
At what dosage is the medication in question prescribed? The administration of such a drug should only be prescribed by a doctor. It is the doctor, relying on data from tests and a medical examination as a whole, must determine the dosage of tablets and the frequency of their use.
Treatment with Letrozole takes a long time. The drug is taken orally, regardless of the meal. According to the instructions, the recommended dosage of this medicine is 2.5 mg once a day.
The medication must be taken every day for 5 years or until relapse develops.
If the drug is used with adjuvant therapy, then taking the tablets should continue for 4 years. With the progression of cancer, the medication is canceled.
In the weaker sex with malignant neoplasms at the last stage or with signs of metastasis, therapy should be continued until the development of the tumor is pronounced.
Overdose cases
Now you know how to take Letrozole. However, this should be done only after consulting a doctor. When taking high doses of the drug, the patient may develop unwanted effects. Currently, there are a number of reports of cases of overdose of the drug in question.
As a treatment for such conditions, supportive and symptomatic therapy is used. Specific methods to eliminate the signs of overdose have not been developed. The drug is removed from the blood using hemodialysis.
The drug "Letrozole": adverse reactions
What adverse reactions occur after taking the drug "Letrozole"? Antitumor tablets often cause unwanted effects. Consider their list right now:
- Digestive system: abdominal pain, stomatitis, diarrhea, dyspepsia, activation of liver enzymes, nausea, dry mouth, constipation, vomiting.
- Nervous system: drowsiness, dizziness, paresthesia, depression, memory impairment, anxiety, insomnia, irritability, hypesthesia, nervousness, passing cerebrovascular disorders, dysesthesia.
- Respiratory system: cough, shortness of breath.
- Hematopoietic system: leukopenia.
- Skin reactions: alopecia, sweating, urticaria, anaphylactic reactions, rash, Quincke's edema, dry skin, itching.
- Circulatory system (heart): coronary heart disease, tachycardia, thromboembolism, palpitations, arterial thrombosis, pulmonary embolism, thrombophlebitis of superficial and deep veins, stroke, increased pressure.
- Musculoskeletal system: osteoporosis, arthralgia, arthritis, myalgia, fractures, bone pain.
- Genitourinary system: various infections, rapid urination, vaginal discharge, bleeding, chest pain.
- Sense organs: perversion of taste, cataracts, blurred vision.
- Other reactions: dry mucous membranes, generalized edema, paroxysmal heat sensations, malaise, fatigue, hyperthermia, asthenia, pain in the area of tumor foci, peripheral edema.
- Metabolism: weight gain, weight loss, hypercholesterolemia, anorexia, increased appetite, constant thirst.
Drug Interactions and Special Recommendations
Clinical trials for taking the medication in question in combination with other antitumor drugs have not been conducted.
The use of the Letrozole agent, reviews of which are ambiguous, can adversely affect a person’s ability to drive vehicles, as well as work with complex mechanisms.
Taking the drug in sports
Medication "Letrozole" in bodybuilding is used quite often. Many athletes claim that taking this medication blocks estrogen synthesis and also increases androgen production. However, experienced specialists argue that the last expected effect has not been scientifically proven. In this regard, doctors do not recommend the use of Letrozole in bodybuilding. Firstly, he has a number of special contraindications, and secondly, this medication has a huge number of side effects.
Thus, after taking the drug in question not according to the prescribed indications, the athlete's health can noticeably worsen.
Storage and sale conditions, expiration date
Where can I get Letrozole medication? Analogues of this tool and the drug itself is sold in almost all pharmacies. However, it is released strictly according to the prescription.
It is desirable to store such a medication in a dry and dark place at a temperature of up to 25 degrees, where there is no access for small children. The shelf life of this medicine is 24 months. After the specified period, the drug is prohibited to use.
Drug Cost and Taxes
Do you know how much Letrozole is worth? The price of this medication may vary slightly depending on the region, manufacturer and pharmacy chain margins. On average, the cost of such an antitumor drug is 1,500 rubles (for 30 tablets). However, this price refers only to a domestic product. The medication of the Spanish company "Kent Pharma" is much more expensive (about 2600 rubles).
Given that Letrozole tablets (side effects have been described above) should be taken for several years, the treatment of malignant neoplasms is very expensive for the patient.
Some patients who are unable to purchase the medication in question replace it with other means (only after consulting a treating doctor). The following medicines are referred to analogues of such a preparation: Aralet, Etrusil, Lersa, Femara, Letrozole Teva, Letrothera, Letromara.
It should be noted that the cost of these drugs can be both higher than the original and lower. For example, 30 tablets of the drug "Femara" cost about 7,700 rubles. However, their effectiveness is not much higher than that of Letrozole.
Patient reviews about the drug
It is quite difficult to find patient reviews about the drug in question. People with cancer are reluctant to share the results of therapy. Most of them failed to achieve remission. Although some patients claim that the Letrozole medication still gave them hope for a longer life.
As for the experts, their feedback is only positive. Based on generally recognized, proven and scientifically based data, they argue that among all anticancer drugs, Letrozole is the most effective drug for treating breast malignancies.
It should also be noted that many patients are frustrated by the price of this medicine. Most of them cannot afford to buy such a medication that aggravates their already unstable emotional state. However, pharmacists argue that the unique technology for the production of such tablets does not allow them to set a lower price.
As for the side effects, according to patients, they are not so pronounced, as indicated in the instructions (especially against the background of existing pain). Most often, this drug causes nausea, tachycardia, urticaria, irritability and diarrhea. However, most people taking such pills are ready to endure all side effects, if only prolonged treatment would contribute to the development of remission.