Zenbrest
Zenbrest Uses, Dosage, Side Effects, Food Interaction and all others data.
The growth of many cancers of the breast is stimulated or maintained by estrogens. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme.
Zenbrest is a selective non-steroidal aromatase inhibitor. It significantly lowers serum estradiol concentrations and has no detectable effect on formation of adrenal corticosteroids or aldosterone.
Zenbrest prevents the conversion of adrenal androgens (e.g. testosterone) to estrogen in peripheral and tumour tissues. As the growth of many breast cancers is stimulated and/or maintained by the presence of estrogen, anastrozole helps to treat these cancers by decreasing the levels of circulating estrogens. Zenbrest has a relatively long duration of action allowing for once daily dosing - serum estradiol is reduced by approximately 70% within 24 hours of beginning therapy with 1mg once daily, and levels remain suppressed for up to 6 days following cessation of therapy.
The incidence of ischemic cardiovascular events was increased during anastrozole therapy and patients with pre-existing ischemic heart disease should consider the risks and benefits of anastrozole before beginning therapy. Zenbrest has also been reported to decrease spine and hip bone mineral density (BMD), so consideration should be given to monitoring of BMD in patients receiving long-term therapy.
Trade Name | Zenbrest |
Availability | Prescription only |
Generic | Anastrozole |
Anastrozole Other Names | Anastrozol, Anastrozole |
Related Drugs | Arimidex, Ibrance, Femara, Aromasin, Faslodex, Verzenio, Afinitor, tamoxifen, Xeloda, Herceptin |
Type | |
Formula | C17H19N5 |
Weight | Average: 293.3663 Monoisotopic: 293.164045633 |
Protein binding | Anastrozole is 40% protein bound in plasma and appears to be independent of plasma concentration. |
Groups | Approved, Investigational |
Therapeutic Class | Hormonal Chemotherapy |
Manufacturer | |
Available Country | Bulgaria, Czech Republic, Slovakia |
Last Updated: | September 19, 2023 at 7:00 am |
![Zenbrest Zenbrest](https://www.medicinesfaq.com/media/png/zenbrest.png)
Uses
Adjuvant treatment of post-menopausal women with hormone receptor-positive early breast cancer, and also advanced breast cancer in post-menopausal women. First-line treatment of hormone receptor-positive post-menopausal women who have received 2 to 3 years of adjuvant tamoxifen.
Zenbrest is also used to associated treatment for these conditions: Advanced Breast Cancer, Early Breast Cancer, Locally Advanced Breast Cancer (LABC), Metastatic Breast Cancer, Invasive, early Breast Cancer
How Zenbrest works
Anastrazole exerts its anti-estrogenic effects via selective and competitive inhibition of the aromatase enzyme found predominantly in the adrenal glands, liver, and fatty tissues. Many breast cancers are hormone receptor-positive, meaning their growth is stimulated and/or maintained by the presence of hormones such as estrogen or progesterone. In postmenopausal women, estrogen is primarily derived from the conversion of adrenally-produced androgens into estrogens by the aromatase enzyme - by competitively inhibiting the biosynthesis of estrogen at these enzymes, anastrozole effectively suppresses circulating estrogen levels and, subsequently, the growth of hormone receptor-positive tumours.
Dosage
Zenbrest dosage
Adults and elderly: 1 mg tablet to be taken orally once a day.
Side Effects
More common side effects are: Blurred vision chest pain or discomfort, dizziness, headache nervousness, pounding in the ears, shortness of breath, slow or fast heartbeat, swelling of the feet or lower legs
Toxicity
The reported oral TDLo in a human woman is 1.68 mg/kg given intermittently over the course of 12 weeks. Knowledge of the signs and symptoms of anastrozole overdose is incomplete as there are no documented descriptions of a patient receiving more than 60mg, a dose which was administered to a healthy male volunteer and was well-tolerated. There is no antidote for anastrozole and treatment should be supportive and symptomatic, including close monitoring of patient vital signs. As anastrozole exhibits relatively low protein binding, dialysis may be helpful and should be considered in select cases.
Precaution
There are no data to support the safe use of anastrozole in patients with moderate or severe hepatic impairment, or patients with severe impairment of renal function (creatinine clearance less than 20 mL/min). Women with osteoporosis or at risk of osteoporosis should have their bone mineral density at regular intervals monitored.
There are no data available for the use of anastrozole with LHRH analogues. This product contains lactose. Patients with rare hereditary problems of galactose intolerance, the lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Interaction
Antipyrine and cemetidine clinical interaction studies indicate that the co administration of anastrozole with other drugs is unlikely to result in clinically significant drug interactions mediated by cytochrome P450. Tamoxifen should not be co-administered with anastrozole as this may reduce its pharmacological action.
Food Interaction
- Take with or without food. Co-administration with food reduces the rate, but not the overall extent, of absorption.
Zenbrest Cholesterol interaction
[Moderate] During a clinical trial, more patients receiving anastrozole were reported to have elevated serum cholesterol compared to patients receiving tamoxifen (9% versus 3.5%, respectively).
Caution should be taken when this agent is prescribed to these patients.
Zenbrest Disease Interaction
Moderate: cardiovascular, cholesterol, hepatic dysfunction, osteoporosis
Volume of Distribution
The volume of distribution of anastrozole into brain tissue in mice is 3.19 mL/g. Distribution into the CNS is limited due to the activity of P-gp efflux pumps at the blood brain barrier, of which anastrozole is a substrate.
Elimination Route
Zenbrest is rapidly absorbed and Tmax is typically reached within 2 hours of dosing under fasted conditions. Coadministration with food reduces the rate but not the overall extent of absorption - mean Cmax decreased by 16% and the median Tmax was extended to 5 hours when anastrozole was administered 30 minutes after ingestion of food, though this relatively minor alteration in absorption kinetics is not expected to result in clinically significant effects.
Half Life
The elimination half-life of anastrozole is approximately 50 hours.
Clearance
Zenbrest's clearance is mainly via hepatic metabolism and can therefore be altered in patients with hepatic impairment - patients with stable hepatic cirrhosis exhibit an apparent oral clearance approximately 30% lower compared with patients with normal liver function. Conversely, renal impairment has a negligible effect on total drug clearance as the renal route is a relatively minor clearance pathway for anastrozole. In volunteers with severe renal impairment, renal clearance was reduced by 50% while total clearance was only reduced by approximately 10%.
Elimination Route
Hepatic metabolism accounts for approximately 85% of anastrozole elimination. Approximately 10% of the administered dosage is eliminated unchanged in the urine.
Pregnancy & Breastfeeding use
Zenbrest is contraindicated in pregnant and lactating women.
Contraindication
Patients with severe renal impairment (Creatinine clearance less than 20 mL/min), patients with moderate to severe hepatic disease and known hypersensitivity to anastrozole or to any of the excipients. Oestrozen-containing therapies should not be co-administered with anastrazole as they would negate its pharmacological action.
Special Warning
Renal impairment: No dose change is recommended in patients with mild or moderate renal impairment.
Hepatic impairment: No dose change is recommended in patients with mild hepatic impairment. For early disease, the recommended duration of treatment should be 5 years.
Acute Overdose
Clinical trials have been conducted with Zenbrest tablets, up to 60 mg in a single dose given to healthy male volunteers and up to 10 mg daily given to postmenopausal women with advanced breast cancer; these dosages were tolerated. A single dose of Zenbrest tablets that results in life-threatening symptoms has not been established. There is no specific antidote to overdosage and treatment must be symptomatic.
In the management of an overdose, consider that multiple agents may have been taken. Vomiting may be induced if the patient is alert. Dialysis may be helpful because Zenbrest tablet is not highly protein bound. General supportive care, including frequent monitoring of vital signs and close observation of the patient, is indicated.
Storage Condition
Product should be stored within 30°C
Innovators Monograph
You find simplified version here Zenbrest
Zenbrest contains Anastrozole see full prescribing information from innovator Zenbrest Monograph, Zenbrest MSDS, Zenbrest FDA label
FAQ
What is Zenbrest used for?
Zenbrest is a medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer. It has also been used to prevent breast cancer in those at high risk.
How safe is Zenbrest?
Zenbrest may cause or worsen osteoporosis. It can decrease the density of your bones and increase the chance of broken bones and fractures. Talk to your doctor about the risks of taking this medication and to find out what you can do to decrease these risks.
How does Zenbrest work?
Zenbrest works by lowering the levels of oestrogen hormones in your body.
What are the common side effects of Zenbrest?
Common side effects of Zenbrest are include:
- weakness
- headache
- hot flashes
- sweating
- stomach pain
- nausea
- vomiting
- loss of appetite
- constipation
- diarrhea
- heartburn
- weight gain
- joint, bone, or muscle pain
- breast pain
- mood changes
- depression
- difficulty falling asleep or staying asleep
- nervousness
- dizziness
- vaginal bleeding
- vaginal dryness or irritation
- pain, burning, or tingling in the hands or feet
- dry mouth
- hair thinning
Is Zenbrest safe during pregnancy?
Zenbrest is used mainly in women after menopause. If you have not gone through menopause, this medication must not be used during pregnancy. It may harm an unborn baby.
Is Zenbrest safe during breastfeeding?
Zenbrest is not recommended when pregnant or breastfeeding, because it interferes with hormone levels in you and your baby.
Can I drink alcohol with Zenbrest?
It's best to avoid or limit alcohol intake when using breast cancer medications like Zenbrest. Alcohol can raise your risk of experiencing side effects from Zenbrest, such as hot flashes or joint pain.
Can I drive after taking Zenbrest?
Do not drive, ride a bike or operate machinery if you feel very tired while taking Zenbrest.
What time of day is best to take Zenbrest?
You may take Zenbrest at whatever time of day you find easiest to remember, but try to take your doses at the same time each day.
Who should not take Zenbrest?
You should not use Zenbrest if you are allergic to it, or if you have not yet completed menopause.
Zenbrest is not approved for use in men or children. You should not take Zenbrest if you also take tamoxifen.
Can I take Zenbrest on an empty stomach?
It is usually taken once a day with or without food.
How often can I take Zenbrest ?
Zenbrest is taken as a tablet once a day. It's best to take it at the same time every day.
How long does Zenbrest take to work?
Zenbrest works quickly to lower estrogen and some side effects start within 24 hours of starting.
How long does Zenbrest stay in your system?
The half life of Zenbrest is 30 to 60 hours. Generally it takes four to five half-lives for a drug to be eliminated from the body, so in the case of Zenbrest this would be 150 to 300 hours, or six to 12 days.
How many years should Zenbrest be taken?
This will depend on your individual circumstances, but Zenbrest is usually taken for five to ten years.
What happens if I miss a dose?
Take the Zenbrest as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
Is Zenbrest toxic?
This Zenbrest can cause liver toxicity, which your doctor will monitor for using blood tests called liver function tests.
Can Zenbrest affect my eyesight?
Based on analysis of OCT retinal thickness data, it is likely that Zenbrest increases the tractional force between the vitreous and retina.
Does Zenbrest affect the heart?
The aromatase inhibitor Zenbrest has been linked to heart attacks and other cardiovascular events.
Does Zenbrest damage the liver?
Liver injury attributed to Zenbrest is usually mild and self-limited, typically a transient, asymptomatic elevation in serum enzymes.
Can Zenbrest affect my kidneys?
Renal dysfunction was considered to be a rare complication of Zenbrest. Patients who are prescribed Zenbrest should be watched carefully for the development of renal dysfunction.
What happens if I overdose of Zenbrest?
Zenbrest may cause your cholesterol levels to rise. Higher cholesterol levels put you at increased risk of heart disease.
How does Zenbrest make me feel?
Zenbrest can sometimes cause headaches, nausea and vomiting.
Can Zenbrest cause memory loss?
A pattern of decline in working memory and concentration with initial exposure to Zenbrest was observed.