What is Anastrozole?

Anastrozole 1 mg is an aromatase inhibitor used mainly to treat hormone-receptor–positive breast cancer in postmenopausal women.
Anastrozole 1 works by lowering estrogen levels, which helps slow or stop the growth of estrogen-dependent cancer cells.

Brand names include:

• Arimidex

• Various generic versions

Manufacturer

Many companies manufacture Anastrozole. Common ones include:

• AstraZeneca (Arimidex – original brand)

• Various Indian generics such as Cipla, Sun Pharma, Natco, etc.

Composition

Each tablet contains:

• Anastrozole 1 mg

Inactive ingredients vary by brand (lactose, povidone, magnesium stearate, etc.)

Working (Mechanism of Action)

Anastrozole works by:

1. Blocking the aromatase enzyme, which converts androgens into estrogen.

2. This reduces estrogen levels in the body.

3. Lower estrogen slows the growth of estrogen-dependent breast cancer cells.

It is not a chemotherapy drug — it is a hormonal therapy.

How to Use Anastrozole

• Take 1 mg tablet once daily

• Take at the same time each day

• Can be taken with or without food

• Swallow whole with water

• Continue long-term unless your doctor advises stopping

Do not stop the medication suddenly without medical advice.

Dosage

Standard dose: 1 mg once daily

Duration typically:

• 5 years (standard treatment)

• Sometimes up to 10 years in high-risk patients

Dosage does not change based on age, weight, or food.

Warnings and Precautions

Do NOT take if:

• You are pregnant or breastfeeding

• You are premenopausal (unless specifically advised)

• You are allergic to Anastrozole

Use with caution if you have:

• Osteoporosis or bone weakness

• High cholesterol

• Heart disease

• Liver problems

• History of stroke or blood clots

Drug Interactions

Avoid or discuss with your doctor:

• Tamoxifen

• Estrogen pills, patches, or creams

• Certain hormone therapies

• Some antidepressants

• Cholesterol-lowering medications

Benefits

• Reduces estrogen levels significantly

• Helps prevent breast cancer recurrence

• Effective in postmenopausal women with hormone-positive tumors

• Reduces the risk of cancer spreading

• Often used after surgery, radiation, or chemotherapy

Avoid Taking Anastrozole If

• You are pregnant or may become pregnant

• You are still having menstrual periods

• You are taking estrogen replacement therapy

• You have severe bone loss without medical supervision

Side Effects

Common:

• Hot flashes

• Joint pain

• Weakness or fatigue

• Mood swings

• Nausea

• Headache

• Bone thinning (osteoporosis)

• Muscle pain

Serious (seek medical help):

• New or worsening bone pain

• Fractures

• Chest pain

• Shortness of breath

• Leg swelling (possible clot)

• Severe allergic reactions

Bone density tests are often done yearly during treatment.

Where to Store

• Store below 25°C

• Keep in a dry place

• Protect from moisture and light

• Keep out of reach of children

• Do not store in the bathroom or hot areas

Conclusion

Anastrozole 1 is a highly effective hormonal therapy used mainly for hormone-positive breast cancer in postmenopausal women.

It works by lowering estrogen, slowing cancer growth, and preventing recurrence.

While generally well-tolerated, it requires monitoring for bone health, cholesterol levels, and cardiovascular risks.