Letrozole Medications

Letrozole Info

What is Letrozole?

Letrozole belongs to a group of medicines called aromatase inhibitors. It lowers the amount of estrogen the body makes and is used mainly to treat certain hormone-sensitive conditions. In Hong Kong, it is available in products such as Femara and generic letrozole tablets.

Medications with Letrozole

The most widely recognised brand containing letrozole is Femara (letrozole tablets). It is sold in 2.5 mg tablets, the dose commonly prescribed for the approved uses. Generic letrozole tablets of the same strength are also available from several manufacturers and appear on the Hong Kong Pharmacy and Poisons Board’s product list.

These products come as oral tablets; there are no liquid or topical forms marketed in Hong Kong. Both brand-name and generic versions are prescription-only medicines, and the packaging carries the same safety information required by the Department of Health.

What Does Letrozole Treat?

Letrozole is used to manage conditions that rely on estrogen for growth or function. The main therapeutic uses include:

• Hormone-receptor-positive breast cancer - helps to slow the growth of tumours that need estrogen.
• Fertility-related ovulation induction - sometimes prescribed off-label to stimulate ovulation in women undergoing assisted reproductive techniques.
• Endometriosis-related pain - can reduce estrogen-driven lesions, easing discomfort (off-label use).
• Premenopausal estrogen-dependent conditions - such as certain gynecological disorders where lowering estrogen provides relief.

These uses are based on clinical evidence and regulatory approval for breast cancer; other applications may be decided by a specialist after individual assessment.

How Letrozole Works

Letrozole blocks the enzyme aromatase, which the body uses to turn other hormones into estrogen. By limiting estrogen production, the drug reduces the hormone’s ability to fuel certain breast cancer cells and other estrogen-dependent tissues. The effect begins within a few days, but the full benefit is usually seen after several weeks of steady use.

Safety Information

Common Side Effects

• Mild headache or dizziness
• Joint or muscle aches
• Hot flashes or night sweats
• Nausea or mild stomach upset

These symptoms are usually temporary and may improve as the body adjusts.

Serious Reactions

• Severe allergic response (rash, swelling of the face, difficulty breathing) - seek emergency care.
• Sudden loss of bone density leading to fractures (long-term use may increase risk).
• Unexplained chest pain or rapid heartbeat - treat as urgent.

Who Should Be Cautious

• Pregnant or breastfeeding women should avoid letrozole because it may affect fetal development.
• Individuals with severe liver disease or uncontrolled heart conditions should discuss use with a qualified health professional.
• People with a history of osteoporosis need close monitoring, as estrogen reduction can impact bone health.

Interaction Awareness

Letrozole may interact with:

• Other hormonal therapies - may alter their effectiveness.
• Medications that affect liver enzymes - can change letrozole levels in the body.
• Alcohol - excessive intake can increase liver strain.

Always refer to the specific product’s information sheet for a full list of potential interactions.

What to Know Before Using

Store letrozole tablets in a cool, dry place away from direct sunlight and out of reach of children. They are intended for short-term or long-term treatment as directed by the prescribing clinician; the duration varies with the condition being treated. Because tablets differ in strength and may be combined with other agents, read the label on your particular medication carefully and follow the instructions that come with it.

Information Disclaimer

This article provides general educational information about letrozole as an active substance used in various medicines. It is intended to help patients understand the ingredient and the conditions it is used to treat. It does not replace professional medical advice or the specific directions supplied with individual products. Medicines containing letrozole can differ in formulation, strength, and usage instructions. Always refer to the labeling of your particular medication and follow the guidance of a qualified healthcare provider for complete information on proper use, dosage, and safety.