Anastrozole

Common Use

Anastrozole is a medication used primarily to treat hormone receptor-positive breast cancer in postmenopausal women—in simple terms, it is a type of cancer where the growth of the tumor is fueled by the hormone estrogen. Anastrozole works by lowering estrogen levels in the body, which helps slow down or stop the growth of estrogen-dependent tumors.

This medication belongs to a class of drugs called aromatase inhibitors. Aromatase is an enzyme that helps produce estrogen in the body after menopause. By blocking this enzyme, anastrozole significantly reduces the amount of estrogen available, depriving the cancer cells of the hormone they need to grow.

Anastrozole is used for:

Early-stage breast cancer – often after surgery (adjuvant therapy) to help prevent the cancer from returning

Advanced (metastatic) breast cancer – to help control the disease and slow its progression

Off-label use – sometimes prescribed for men with conditions related to high estrogen levels, such as gynecomastia (enlargement of breast tissue)

Dosage and Direction

Anastrozole is taken orally once daily, usually as a 1 mg tablet, with or without food. It is important to take it at the same time each day to help maintain consistent levels in your body.

Follow your doctor’s instructions carefully. Do not stop treatment without medical advice, even if you are feeling well—consistency is key to managing the disease effectively.

Precautions

Before starting anastrozole, inform your doctor if you have:

Osteoporosis (weak, brittle bones) or a history of bone fractures

Liver disease

A history of cardiovascular problems (such as heart disease, high cholesterol, or heart attack)

Bone health: Anastrozole can cause bone thinning (decreased bone density) because estrogen helps protect bones. Your doctor may recommend calcium and vitamin D supplements to support bone health, and you may need regular bone density scans (DEXA scans) to monitor your bones during treatment.

Regular monitoring: Your doctor will likely arrange regular blood tests to monitor liver function and hormone levels throughout your treatment.

Contraindications

Anastrozole should not be used in the following situations:

Premenopausal women – the medication is designed for postmenopausal women; it is not effective in women who still have regular menstrual cycles

Pregnancy or breastfeeding – anastrozole can harm a developing baby and should not be used during pregnancy or while nursing

Allergy – if you are allergic to anastrozole or any of its ingredients

With estrogen-containing therapies – anastrozole should not be taken together with estrogen-containing medications, tamoxifen, or hormone replacement therapy (HRT), as they can interfere with its effectiveness

Severe osteoporosis – unless the benefits clearly outweigh the risks, as anastrozole can further weaken bones

Possible Side Effects

Common side effects may include:

Hot flashes – sudden feelings of warmth, often in the face and chest

Joint pain or stiffness – sometimes called aromatase inhibitor-associated arthralgia

Fatigue (tiredness)

Nausea

Headache

Insomnia (trouble sleeping)

Mood changes or depression

Serious side effects (less common but require medical attention) may include:

Osteoporosis or bone thinning – leading to an increased risk of fractures

Heart problems – such as chest pain (angina), heart attack, or changes in cholesterol levels

Liver abnormalities – which may show as yellowing of the skin or eyes (jaundice), dark urine, or abdominal pain

Severe allergic reactions – such as rash, swelling, or difficulty breathing

Seek medical help immediately if you experience chest pain, shortness of breath, severe weakness, or yellowing of the skin or eyes.

Drug Interactions

Anastrozole can interact with certain medications:

Avoid taking anastrozole with:

Estrogen-containing medications – including hormone replacement therapy (HRT) and estrogen-based contraceptives

Tamoxifen – another breast cancer medication that can interfere with anastrozole’s effectiveness

Inform your doctor about all other medications you are taking, including:

Prescription drugs

Over-the-counter products

Supplements and herbal products (such as St. John’s wort, which may affect hormone levels)

Missed Dose

If you miss a dose, take it as soon as you remember—unless it is almost time for your next dose. If that’s the case, skip the missed dose and continue with your regular schedule. Do not double the dose to make up for a missed one.

Overdose

Symptoms of anastrozole overdose are not well defined but may include:

Dizziness

Weakness

Nausea and vomiting

Gastrointestinal upset

If you suspect an overdose, seek emergency medical attention immediately.

Storage

Store anastrozole at room temperature, away from light, moisture, and heat. Keep it in its original packaging and out of reach of children.

Disclaimer

We provide only general information about medications, which does not cover all directions, possible drug interactions, or precautions. Information on this site cannot be used for self-treatment or self-diagnosis. Any specific instructions for a particular patient should be agreed upon with your healthcare adviser or the doctor in charge of your case. We disclaim reliability of this information and any mistakes it may contain. We are not responsible for any direct, indirect, special, or other indirect damage as a result of any use of the information on this site, nor for the consequences of self-treatment.

About Our Service Cydoctors.com is an online pharmacy based right here in Cyprus. We understand that when you’re undergoing breast cancer treatment, having reliable, consistent access to your medication is absolutely essential—so we’ve made our service straightforward, dependable, and built with your peace of mind in mind. Because we’re local to the island, we can arrange delivery in the shortest possible time. For our customers in Nicosia, Limassol, and Paphos, we’re pleased to offer overnight delivery, so your anastrozole can be with you by the next day, helping you stay on track with your treatment and giving you one less thing to worry about.