Main Information
- Drug : Anastrozole
- What is : A non-steroidal aromatase inhibitor
- Concentrarion : 1mg / capsule
- Package : 60 capsules flask
- Excipients : Cellulose Microcrystalline, Magnesium Stearate
- Aspect : White / Blue capsule
- Pharmaceutical form : Capsule
- Administrarion : Oral
Synonyms
- Arimidex
- Anastrole
- Asiolex
- Anastrolibbs
Descripition
Anastrozole is a non-steroidal inhibitor of aromatase which effectively blocks estrogen synthesis in postmenopausal women and is used as therapy of estrogen receptor positive breast cancer. Anastrozole has been associated with a low rate of serum enzyme elevations during therapy and rare instances of clinically apparent liver injury.
Mechanism of action : 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.
Anastrozole 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.
Indications
Anastrozole is indicated for adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer.
Anastrozole is indicated for the first-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor unknown locally advanced or metastatic breast cancer.
Anastrozole is indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy. Patients with ER-negative disease and patients who did not respond to previous tamoxifen therapy rarely responded to Anastrozole.
Contraindications
Anastrozole may cause fetal harm when administered to a pregnant woman and offers no clinical benefit to premenopausal women with breast cancer. Anastrozole is contraindicated in women who are or may become pregnant. There are no adequate and well-controlled studies in pregnant women using Anastrozole. If Anastrozole is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus or potential risk for loss of the pregnancy.
Anastrozole is contraindicated in any patient who has shown a hypersensitivity reaction to the drug or to any of the excipients. Observed reactions include anaphylaxis, angioedema, and urticaria.
Drug Interactions
- Tamoxifen : Co-administration of anastrozole and tamoxifen in breast cancer patients reduced anastrozole plasma concentration by 27%. However, the co-administration of anastrozole and tamoxifen did not affect the pharmacokinetics of tamoxifen or N-desmethyltamoxifen. At a median follow-up of 33 months, the combination of Anastrozole and tamoxifen did not demonstrate any efficacy benefit when compared with tamoxifen in all patients as well as in the hormone receptor-positive subpopulation. This treatment arm was discontinued from the trial [see Clinical Studies]. Based on clinical and pharmacokinetic results from the ATAC trial, tamoxifen should not be administered with anastrozole.
- Estrogen : Estrogen-containing therapies should not be used with Anastrozole as they may diminish its pharmacological action.
- Warfarin : In a study conducted in 16 male volunteers, anastrozole did not alter the exposure (as measured by C max and AUC) and anticoagulant activity (as measured by prothrombin time, activated partial thromboplastin time, and thrombin time) of both R-and S-warfarin.
- Cytochrome P450 : Based on in vitro and in vivo results, it is unlikely that co-administration of Anastrozole 1 mg will affect other drugs as a result of inhibition of cytochrome P450.
Dosage
Always take Anastrozole exactly as your doctor or pharmacist prescribed. Check with your doctor or pharmacist if you are not sure.
The recommended dose is one capsule once a day.
Try to take your capsule at the same time each day.
Swallow the capsule whole with a drink of water.
It does not matter if you take Anastrozole before, with or after food.
Keep taking Anastrozole for as long as your doctor or pharmacist prescribed. It is a long-term
treatment and you may need to take it for several years. Check with your doctor or pharmacist if you are not sure.
Use in children and adolescents
Anastrozole should not be given to children and adolescents.
Adverse Reactions
Like all medicines, this medicine can cause adverse reactions, although not everybody gets them.
Very common adverse reactions (affect more than 1 in 10 people)
- Headache
- Hot flushes
- Feeling sick (nausea)
- Skin rash
- Pain or stiffness in your joints
- Inflammation of the joints (arthritis)
- Feeling weak
- Bone loss (osteoporosis)
Common adverse reactions (affect 1 to 10 people in 100)
- Loss of appetite
- Raised or high levels of fatty substance known as cholesterol in your blood. This would be seen in a blood test
- Feeling sleepy
- Carpal tunnel syndrome (tingling, pain, coldness, weakness in parts of the hand)
- Tickling, tingling or numbness of skin, loss/lack of taste
- Diarrhoea
- Being sick (vomiting)
- Changes in blood tests that show how well your liver is working
- Thinning of your hair (hair loss)
- Allergic (hypersensitivity) reactions including face, lips, or tongue
- Bone pain
- Vaginal dryness
- Bleeding from the vagina (usually in the first few weeks of treatment - if the bleeding continues, talk to your doctor)
- Muscle pain
Uncommon adverse reactions (affect 1 to 10 people in 1,000)
- Changes in special blood tests that show how your liver is working (gamma-GT and bilirubin)
- Inflammation of the liver (hepatitis)
- Hives or nettle rash
- Trigger finger (a condition in which your finger or thumb catches in a bent position)
- Increased amounts of calcium in your blood. If you experience nausea, vomiting and thirst, you should tell your doctor, or pharmacist or nurse as you may need to have blood tests
Rare adverse reactions (affect 1 to 10 people in 10,000)
- Rare inflammation of your skin that may include red patches or blisters
- Skin rash caused by hypersensitivity (this can be from allergic or anaphylactoid reaction)
- Inflammation of the small blood vessels causing red or purple colouring of the skin. Very rarely symptoms of joint, stomach, and kidney pain may occur; this is known as 'Henoch-Schönlein purpura'
Very rare adverse reactions (affect less than 1 person in 10,000 people)
- An extremely severe skin reaction with ulcers or blisters on the skin. This is known as 'Stevens-Johnson syndrome'
- Allergic (hypersensitivity) reactions with swelling of the throat that may cause difficulty in swallowing or breathing. This is known as 'angioedema'
If any of these happen to you, call an ambulance or see a doctor straight away - you may need urgent medical treatment.
Effects on your bones : Anastrozole lowers the amount of the hormone called estrogen that is in your body. This may lower the mineral content of your bones. Your bones may be less strong and may be more likely to fracture. Your doctor will manage these risks according to treatment guidelines for managing bone health in women who have gone through the menopause. You should talk to your doctor about the risks and treatment options.
If any of the adverse reactions get serious, or if you notice any adverse reactions not listed in this leaflet, please tell your doctor or pharmacist.
Storage
Anastrozol should be stored at 20° to 25°C (68° to 77°F).
History
Anastrozole is an extremely powerful anti-estrogen officially belonging to the Aromatase Inhibitor (AI) family. Developed in the early 1990's by Zeneca Pharmaceuticals and released in 1995 under the trade name Arimidex, this is perhaps the most commonly used AI and one of the most common anti-estrogens on the market. Anastrozol has proven to be very effective in breast cancer treatment, even more so than traditional Nolvadex (Tamoxifen Citrate), and is a favorite anti-estrogen among many anabolic steroid users. Countless anabolic steroid users rely on Anastrozol for on cycle estrogenic protection. Many anabolic steroids have the ability to aromatase and lead to excess estrogen, which in turn can lead to some of the most commonly associated side effects of anabolic steroid use.
Functions
The functions of Anastrozol although powerful are extremely simple. As an AI Anastrozol works by blocking the aromatase enzyme, which is in turn responsible for the production of estrogen. By inhibiting the aromatase process, Anastrozol will lower the body's serum estrogen levels; in fact, a total suppression of estrogen by 80% has been well noted with this AI. This will prove very beneficial to numerous breast cancer patients and extremely valuable to many anabolic steroid users. Anastrozol also has the ability to stimulate the release of Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH), two hormones essential to natural testosterone production. This has led some physicians to use the AI in low testosterone treatment plans in place of testosterone, but it's generally not the best choice.
Effects
As an anti-estrogen, Anastrozol is valuable to the breast cancer patient as many forms of breast cancer feed off of the estrogen hormone. While perhaps an oversimplification, by administering Anastrozol the effect starves the cancer. For decades Nolvadex was used for this purpose. Nolvadex has the ability to bind to the estrogen receptors, which in turn prevents estrogen from binding. However, AI's like Anastrozol actively inhibit the production of estrogen and reduce the actual amount of circulating hormone. In short, there is no estrogen available to cause damage to the breast cancer patient. In recent years, Anastrozol has become the leading anti-estrogen in the treatment of hormone receptor-positive breast cancer, especially among post-menopausal women. Once the cancer has subsided, it is not uncommon for Nolvadex to be introduced in order to keep the cancer at bay.
For the anabolic steroid user, the effects of Anastrozol are greatly appreciated in its ability to protect against estrogenic related side effects. Many anabolic steroids have the ability to promote estrogenic side effects due to the testosterone hormone's interaction with the aromatase enzyme. As aromatization occurs, estrogen levels rise and this can lead to gynecomastia and excess water retention. When excess water retention becomes severe, this can also promote high blood pressure. Not all anabolic steroids aromatize, and as such, not all can lead to estrogenic related effects. However, many common steroids do carry the ability to promote estrogenic activity including Dianabol, all forms of Nandrolone and Boldenone to a degree and of course, all forms of testosterone heavily.
By including Anastrozol in an anabolic steroid cycle that contains aromatizing steroids, the individual can protect against gynecomastia and water retention. This will also protect against high blood pressure. Some steroids can still cause high blood pressure without water retention, but heavy excess water retention is the number one culprit of high blood pressure among anabolic steroid users. Without question, AI's like Anastrozol are the most effective anti-estrogens for combating estrogenic related side effects. SERM's like Nolvadex can also be useful and while not as effective should be the first choice when possible. Anastrozol has the ability to negatively affect cholesterol as we will see in the side effects section. However, we will also find cholesterol issues can be avoided.
As a testosterone stimulating compound, Anastrozol can be appealing for low testosterone treatment plans and for Post Cycle Therapy (PCT) for anabolic steroid users. In the case of low testosterone treatment, it's often not enough. However, it can still be beneficial in conjunction with exogenous testosterone therapy in protecting against estrogenic side effects. As for PCT use, some will attempt it and it can have a positive effect, but it is generally not recommended. The main purpose of a PCT plan is to stimulate natural testosterone production in order to protect lean muscle tissue, keep body fat under control and promote a better state of health. However, the overall purpose is normalization, which cannot be reached when using Anastrozol post cycle due to the tremendous estrogen reduction. Although high levels of estrogen can be problematic, some is necessary to proper bodily function, especially regarding the immune system and cardiovascular health. For the anabolic steroid user, AI's should be saved for on cycle use with SERM's being used for PCT.
Side Effects
Anastrozol carries with it several possible side effects. Many of the side effects of Anastrozol will be response related. Response side effects are common with all medications; some of us can take Aspirin while others can't. The side effects of Anastrozol will also vary depending on anabolic steroid use in a few specific areas. Those who are using Anastrozol without anabolic steroids often report weakness and fatigue; in fact, this may be the most common side effect of Anastrozol. Most anabolic steroid users will not have this issue with low dose Anastrozol use. However, we can make an exception when it is used in hard cutting or competition cycles when calories are very low and training often extremely intense. Other possible side effects of Anastrozol use include:
- Headache
- Hot Flashes
- High Blood Pressure
- Joint Pain
- Depression (rare)
- Nausea and or Vomiting (rare)
Anastrozol studies have also shown that the AI may have the ability to decrease bone mineral content, which in turn could make the individual more susceptible to osteoporosis. This shouldn't be a big issue for anabolic steroid users as many anabolic steroids have the ability to promote bone mineral content. As for the primary six possible side effects of Anastrozol listed above, while possible most adults should be able to use the AI without any related issues, but keep in mind such issues are possible. We all respond to varying medications differently, we even respond to varying foods differently, which can make total response on an individual basis impossible to fully predict.
The final issue revolving around the side effects of Anastrozol surrounds cholesterol. Anastrozol does have the ability to negatively effect cholesterol levels, but alone it doesn't appear to be significant in most cases. However, when conjoined with anabolic steroid use, specifically an aromatizing steroid like testosterone it appears to be significant. For example, studies have shown that a moderate dose of Testosterone Enanthate for 12 weeks does not appear to have a strong affect on cholesterol. However, when this same dose is coupled with an AI like Anastrozol it can suppress HDL cholesterol by as much as 25%. In this case, we're actually talking about therapeutic level doses as well as performance. True performance doses of testosterone will have a stronger impact on HDL cholesterol, and again around a 20%+ decrease in HDL when conjoined with an AI.
Due to the potential cholesterol issues brought on by Anastrozol use by the anabolic steroid user, a healthy and cholesterol friendly lifestyle is extremely important. A healthy lifestyle should first and foremost surround your diet. Diets should be low and very limited in saturated fats and simple sugars. They should also be rich in omega fatty acids. Daily fish oil supplementation is advised. It's also worthwhile to consider the use of a cholesterol antioxidant supplement. And as a final note, if cardiovascular health is to be protected the individual should always incorporate plenty of cardiovascular training into his routine. Daily cardiovascular activity is recommended.
Due to the possible cholesterol issues, moderate anabolic steroid cycles may be best served with SERM's in order to protect against estrogenic related side effects. SERM's will not negatively affect cholesterol; in fact, SERM's like Nolvadex have been shown to promote healthy cholesterol levels due to their ability to act as estrogen in the liver. However, for many a SERM won't be enough and AI's will be necessary. If an AI is necessary, the individual should limit his use and only use as much as is actually needed. Some have suggested that a 10mg per day dosing of Nolvadex along with your Anastrozol use may actually aid in cholesterol management.
Administration
In the treatment of breast cancer, Anastrozol is almost always dosed at 1mg per day until the cancer subsides. Use may continue for a time at this stage and will often be switched to Nolvadex in a preventative measure once the cancer is in remission.
For the anabolic steroid user, Anastrozol doses can vary with 0.5-1mg every other day being the most common. Very few should ever need more than 1mg every other day and many will be more than fine with half that amount. In therapeutic plans such as low testosterone treatment even less may be needed. We can, however, make an exception in Anastrozol doses for competitive bodybuilders. Competitive bodybuilders may find a full 1mg every day the last 10-14 days leading up to competition to be useful. This will greatly aid in hardening, but it will be draining to say the least. Of course, at this stage of a competition diet most have very little energy to begin with anyway.
Reviews
There are several Aromatase Inhibitors available, Femara (Letrozole), Aromasin (Exemestane) and Anastrozol (Anastrozole) being the most common. All three are very similar and while all three carry slight differences that make them unique many agree Anastrozol may be the most valuable of all. Anastrozol is generally the modern preferred anti-estrogen in breast cancer treatment, as well as the preferred AI in low testosterone treatment plans. For the anabolic steroid user, it is highly efficient and should be the only AI you need. However, in cases where gynecomastia symptoms are already beginning to show, many report heavy Letrozole doses to be the answer to the remedy, where in time switching to Anastrozol as a preventative measure. However, in the end, for the performance enhancing athlete, he may need to try all three at varying times to find which AI works best for him.
