Tiadis

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Tiadis

Property Description
Active Ingredient Letrozole (C17H11N5)
Form Film-coated tablet
Pharmacological Class Third-Generation Nonsteroidal Aromatase Inhibitor (AI)
General Purpose Endocrine modulation via estrogen suppression
Origin Synthetic

What Type of Medicine is Tiadis (Letrozole)?

Tiadis is a synthetic, single-ingredient prescription agent officially classified as a third-generation nonsteroidal aromatase inhibitor (AI). The active substance is Letrozole, placing the drug within the larger pharmacological groups of antiestrogens and antineoplastic agents. It is manufactured for systemic effect as an oral film-coated tablet.

As a third-generation AI, Letrozole is distinctively potent and selective compared to older hormone therapies. This nonsteroidal structure is a key differentiating factor, allowing for a highly targeted blockade of the aromatase enzyme. This high specificity ensures the mechanism primarily affects estrogen synthesis without significantly interfering with the production of other crucial adrenal hormones, such as cortisol.


What is the General Purpose of an Aromatase Inhibitor?

The general purpose of Tiadis is endocrine modulation, achieved through the sustained and significant reduction of the body's circulating estrogen levels. This medication is clinically recognized for its efficacy in reducing the amount of estrogen produced by the body.

The mechanism involves Letrozole acting as a Type II inhibitor that selectively binds to the aromatase enzyme. This enzyme blockade prevents the final biological step—the biosynthesis of estrogens (estrone, estradiol, and estrone sulfate) from their androgen precursors in peripheral tissues. The resulting profound suppression of serum estrogen serves as the foundational therapeutic benefit by diminishing the hormonal support available for estrogen-sensitive biological processes.

Regulatory References

  1. Letrozole Drug Information (MedlinePlus)

What side effects are possible with Tiadis?

The safety profile of Tiadis (Letrozole) is officially characterized by systemic adverse reactions resulting from profound estrogen suppression, as documented in government regulatory sources, including the EMA and FDA. These effects are organized by frequency and the body's System-Organ Classes (SOCs).

Frequency-Classified Adverse Reactions

The most frequently reported effects, classified as Very Common (ge 1/10), include hot flushes, arthralgia (joint pain), fatigue (asthenia), increased sweating (hyperhidrosis), and hypercholesterolemia. Reactions classified as Common (ge 1/100 to <1/10) cover a wide range of SOCs, such as musculoskeletal disorders (e.g., bone pain, osteoporosis, bone fractures), nervous system disorders (e.g., headache, dizziness), and gastrointestinal disorders (e.g., nausea, vomiting, constipation, diarrhea).

Serious Adverse Reactions and Safety Constraints

Official labeling documents highlight specific, clinically significant safety concerns. Skeletal events, including an increased risk of osteoporosis and bone fractures, are associated with long-term use, and monitoring of Bone Mineral Density (BMD) is required. Serious cardiovascular events and thromboembolic events, such as myocardial infarction, cerebrovascular accident, and arterial thrombosis, are also documented. The most frequent reactions typically occur during the initial few weeks of treatment.

Population-Specific Safety

Tiadis is contraindicated in women with a premenopausal endocrine status and during pregnancy due to the confirmed risk of Embryo-Fetal Toxicity. Caution is also warranted for patients with severe hepatic impairment due to altered systemic exposure.

Overdose and Emergency Response

Overdose Scope

Property Description
Documented overdose presentations Isolated cases of Letrozole overdose have been reported, with the highest single dose documented as 125 mg (50 tablets). In these known instances, no serious adverse reactions were officially associated with the ingestion.
Physiological systems affected (as stated in label) Regulatory documents mandate frequent monitoring of vital signs, necessitating management of potential effects on cardiovascular, respiratory, and central nervous systems.
Dose-related or exposure-related factors The highest reported single dose is 125 mg.
Population-specific overdose notes Not specified in the official overdose section.
Emergency-response statements Treatment should be symptomatic and supportive. Administration of activated charcoal may be appropriate, and emesis could be induced if the patient is alert.
When immediate medical help is required Seek emergency medical attention or call the Poison Control Center. Immediately call emergency services if the victim has collapsed, experienced a seizure, has trouble breathing, or can't be awakened.

Overdose Classifications (High-Level)

Property Description
Severity classification No firm recommendations for specific treatment can be made due to limited clinical data.
Overdose-context constraints No specific antidote is known for the substance.

Official Overdose Statements

  • No serious adverse reactions were documented in the reported cases of overdose, with the highest single dose being 125 mg.
  • Treatment is symptomatic and supportive, and involves frequent monitoring of vital signs.
  • Regulatory authorities mandate calling emergency services immediately if severe signs such as collapse, seizure, or trouble breathing occur.

The official regulatory profile for Tiadis overdose is characterized by limited clinical data, stating that known ingestions up to 125 mg resulted in no serious adverse reactions. Due to the absence of a specific antidote, management strictly involves symptomatic and supportive care, and the label establishes clear, life-threatening clinical signs that mandate immediately seeking emergency medical attention.

Therapeutic Uses of Tiadis

Tiadis is commonly used within the therapeutic domain of hormone receptor-positive breast cancer in postmenopausal women, providing management across several key therapeutic contexts. The medicine is used to help manage long-term recurrence risk (in adjuvant and extended adjuvant contexts), for systemic management of advanced or metastatic disease, and to support tumor volume reduction in the neoadjuvant setting before surgery. This therapy is relevant in conditions where cancer cells rely on hormonal factors, and its goal is to help minimize the likelihood of recurrence and stabilize progressive tumor activity.

Quick Fact: Relief for Cancer Progression

This medication generally plays a role in managing symptoms related to systemic imbalance by assisting with the control of the underlying disease. It is considered relevant in conditions presenting with systemic or localized discomfort. The therapy is commonly used in conditions presenting with recurrent or episodic manifestations to contribute to easing the overall symptom load.

Eligibility and Restrictions for Use

The eligibility for using Tiadis (Letrozole) is strictly defined by regulatory authorities based on endocrine status and specific health criteria.

Populations for Whom Use is Allowed (Official Labeled Use)

  • Postmenopausal Women only (menopause must be clearly established, typically by laboratory assessment of hormones like FSH/LH if unclear).
  • Adult and Older Adult Patients (ge 65 years). No general dose adjustment is required for patients over 65.

Populations for Whom Use is Contraindicated (Must Not Use)

Classification Population/Condition Regulatory Basis
Absolute Contraindication Women who are pregnant or breastfeeding (lactating) FDA, EMA, TGA
Absolute Contraindication Women of premenopausal endocrine status FDA, EMA, TGA
Absolute Contraindication Known hypersensitivity to Letrozole or any product excipient FDA, EMA, TGA

Use is Restricted or Not Recommended

  • Pediatric Use: Use in children and adolescents (under 18 years) is not recommended as safety and effectiveness have not been established by regulators.
  • Severe Hepatic Impairment: Patients with severe hepatic impairment (Child-Pugh C) require close supervision and a modified regimen due to significantly increased drug exposure (e.g., doubling of systemic exposure).
  • Severe Renal Impairment: Use is restricted in patients with severe renal insufficiency ( Creatinine Clearance < 10 mL/min) because data in this population are insufficient to make a standard recommendation.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents define the interaction profile of Tiadis (Letrozole) through specific restrictions and documented pharmacokinetic alterations. This information is based solely on authoritative government sources such as the FDA and EMA labeling.

Documented Interaction Classifications

Interaction Type Officially Documented Entity Official Regulatory Outcome
Functional Restriction Estrogens or Estrogen-Containing Products Co-administration must be avoided due to pharmacodynamic antagonism that compromises efficacy.
Pharmacokinetic Tamoxifen Combination results in a substantial reduction of Letrozole plasma levels.
Metabolic CYP3A4 and CYP2A6 Inhibitors Letrozole is metabolized by these enzymes; strong inhibitors may lead to increased systemic exposure.

Other Relevant Interactions and Constraints

Pharmacokinetic studies found no clinically significant effect on the pharmacokinetics of Letrozole when co-administered with Cimetidine or Warfarin.

The label notes that the risk of central nervous system (CNS) effects, specifically dizziness and sleepiness, may be increased when alcohol is consumed. Furthermore, the official documents state that the absorption of the medicine is not affected by food.

A key population-specific constraint exists for patients with severe hepatic impairment (cirrhosis), who exhibit approximately twice the systemic exposure (AUC) to Letrozole and reduced clearance compared to healthy individuals.

Mechanism of Action

Selective Blockade of the Aromatase Enzyme ( CYP19A1)

Tiadis works by acting as a selective, non-steroidal competitive inhibitor that binds reversibly to the Aromatase enzyme ( CYP19A1). This molecular interaction occurs at the enzyme's active site, coordinating with the heme iron to physically shut down its function without significantly interfering with other CYP-mediated adrenal steroidogenesis.


Interruption of Estrogen Biosynthesis

The blockade prevents the final biochemical step—the aromatization of androgen precursors (like androstenedione) into estrogens ( estradiol and estrone) in peripheral tissues. This focused pathway interruption results in the supply of estrogen being limited at its source.


Profound Systemic Estrogen Suppression

The ultimate physiological consequence of this cascading mechanism is the creation of a state of hypoestrogenism, leading to a sustained reduction of circulating estrogen levels by typically more than 98%. This specific hormonal modulation is the resulting physiological consequence of the CYP19A1 blockade.

Dosage and Administration Information

Tiadis is administered orally as a 2.5 mg film-coated tablet. The general usage principle involves taking one 2.5 mg tablet once daily, which represents the standard regimen for all approved indications. This schedule is designed to ensure a consistent daily systemic exposure to the active substance, Letrozole.


Administration Guidelines

The procedural principles for administering Tiadis are as follows:

Administration Parameter Official Instruction
Route of Administration Oral only (tablet must be swallowed whole)
Food Relation May be taken with or without food (without regard to meals)
Standard Frequency Once daily (qDay)
Geriatric/Renal Patients No dose adjustment required
Severe Hepatic Impairment Dose reduced to 2.5 mg every other day

Treatment Duration and Timing

The overall length of treatment is conditional on the management context. For use in the adjuvant setting, the duration is typically a fixed course of five years, or continues until a tumor relapse occurs. Conversely, for the management of advanced or metastatic disease, administration continues until disease progression is observed.

To maintain the required systemic consistency, the tablet is generally administered at the same time each day. If a dose is missed, it should be taken as soon as the patient remembers; however, if it is close to the time for the next scheduled dose, the missed tablet must be skipped to avoid the consumption of two doses within a short timeframe.

Recent Clinical Evidence

Tiadis: Recent Clinical Evidence

The understanding of Tiadis (Letrozole) is based on large, controlled clinical trials, which are a robust research design, that focuses on hormone receptor-positive breast cancer in postmenopausal women. The research explores specific, measurable outcomes but offers no guarantees about how the medicine will affect any individual patient.


Initial and Extended Adjuvant Treatment

Large studies explored Tiadis for a five-year period following early-stage surgery, evaluating it against other hormone therapies. Disease-Free Survival (DFS) was a key metric. Findings described patterns in long-term disease status and recurrence rates over follow-up periods extending many years. Separately, placebo-controlled trials explored using Tiadis for an additional five years. These studies monitored recurrence and Overall Survival (OS). Evidence regarding a consistent OS pattern in the extended setting remains mixed across trials. Research is complicated by patient crossover in some initial trials, and data for non-postmenopausal populations remain insufficient.


Advanced Disease and Research Gaps

For advanced or metastatic disease, Tiadis was studied as a first-line treatment. Studies monitored outcomes such as Time to Progression (TTP) and Objective Response Rate (ORR) (measurable reduction in tumor size). Findings were mixed across some subgroups. Uncertainty remains regarding a consistent OS benefit in the extended adjuvant setting. Data is insufficient for specific patient subgroups with significant pre-existing health conditions. Comparative evidence versus other Aromatase Inhibitors over the very long term is also limited. The long-term observation of outcomes related to physical discomfort or systemic/functional imbalance is not fully established.

Key Studies & References

  1. Letrozole versus tamoxifen as first-line therapy of advanced breast cancer in postmenopausal women: a multicenter randomized trial with median follow-up of 2.6 years

Frequently Asked Questions (FAQ)

Common questions about Tiadis (FAQ)


Q: Is Tiadis the same as [Commonly confused drug name]?

Tiadis is the brand name for the active ingredient called Letrozole. The active substance in Tiadis is Letrozole, which is also available from other manufacturers under its generic name. Official regulatory documents classify Tiadis as a third-generation non-steroidal aromatase inhibitor.


Q: Is Tiadis a type of steroid?

Tiadis is officially classified as a non-steroidal aromatase inhibitor. This means its chemical structure is not based on a steroid molecule, a detail noted in its pharmacological classification.


Q: How quickly does Tiadis start to work?

The active ingredient begins to lower estrogen levels immediately after starting treatment. However, evidence from studies indicates that the full therapeutic effect may take several weeks or months to be observed.


Q: Is it normal to feel a bit nauseous when starting Tiadis?

Nausea is classified as a common side effect in the official safety profile. The most frequent reactions are typically reported during the initial few weeks of treatment.


Q: Does Tiadis cause weight gain?

Official regulatory information notes 'changes in weight' as a possible symptom associated with the medicine. Some regulatory-aligned patient information classifies weight increase as a common side effect.


Q: What happens if I stop taking Tiadis suddenly?

Official regulatory instructions specify how to handle a missed dose, but they do not provide specific guidance on discontinuing the full treatment regimen. Discontinuation of treatment is associated with the improvement of most related side effects, typically within a week or two.


Q: Are there any long-term effects of taking Tiadis?

Long-term use is associated with potential changes, particularly due to the profound suppression of estrogen. Official regulatory warnings highlight risks such as decreased bone mineral density (osteoporosis) and increased cholesterol levels, which may require monitoring.


Q: Is it true that Tiadis requires regular monitoring or blood tests?

Yes, the official prescribing information states that monitoring should be considered for certain health metrics. Specifically, monitoring of bone mineral density (BMD) and serum cholesterol is recommended due to documented potential changes.


Q: Is it safe to take Tiadis with pain relievers like ibuprofen?

Major regulatory drug interaction reviews do not report a clinically significant pharmacokinetic interaction between the active ingredient (letrozole) and common over-the-counter pain relievers like ibuprofen.


Q: Are there any known interactions between Tiadis and supplements like St. John's Wort?

The medicine is metabolized by enzymes like CYP3A4. Official safety information indicates that supplements, such as St. John’s Wort, that are known to induce these enzymes may reduce the medicine's effectiveness.


Q: Are there reports of Tiadis interacting with birth control pills?

Official documents state that co-administration with estrogen-containing products is to be avoided because this can compromise the medicine’s primary therapeutic goal. This restriction applies to combination oral contraceptives.


Q: Can women who are planning pregnancy use Tiadis?

Regulatory documents state that females of reproductive potential must use effective contraception during therapy and for at least three weeks after the last dose. A pregnancy test is required prior to starting therapy.


Q: Does Tiadis show up on a standard drug test?

The drug is not classified as a controlled substance by US authorities. However, the active ingredient is specifically listed as a prohibited substance by the World Anti-Doping Agency (WADA) due to its hormone-modulating effects.


Q: What is the 'off-label' use controversy surrounding Tiadis?

The official documentation only provides information for the specific uses for which the medicine has been reviewed and approved by regulatory authorities. Information about uses outside of the approved label is not included in official prescribing documents.


Q: Is Tiadis a habit-forming medicine?

No, the drug is not classified as a controlled substance by regulatory bodies like the US Drug Enforcement Administration (DEA). Therefore, it is not considered a habit-forming medicine.


Q: Is Tiadis available over the counter in any country?

Official drug status documents confirm that Tiadis is a prescription-only medication. It is not available over the counter.


Q: Are there patient assistance programs for Tiadis?

The manufacturer of the brand-name version provides patient support services. These programs offer assistance and copay savings for eligible patients who meet specific income and insurance criteria.


Q: Can Tiadis make it difficult to sleep?

Official safety documentation lists difficulty falling asleep or staying asleep (insomnia) as a common side effect of the medicine.


Q: Is the research evidence for Tiadis considered strong?

The drug's regulatory approval for its indicated uses is based on large, controlled clinical trials. These studies assessed measurable outcomes such as disease-free survival and time to progression, which form the basis of the official prescribing information.


Q: Can Tiadis affect my mood?

Official safety documents indicate that mood-related changes have been reported. These changes can include symptoms such as depression, anxiety, and nervousness, and they are listed as common or uncommon side effects in the product monograph.

How should Tiadis be stored and disposed of?

How to Store and Dispose of Tiadis?

Official regulatory documents define strict requirements for storing and disposing of Tiadis (Letrozole) to maintain product integrity and environmental safety.

Required Storage Conditions

Condition Requirement
Temperature Store at 25 C (77 F), with permitted excursions between 15 C and 30 C (59 F and 86 F).
Protection Keep in the original container and protected from moisture and excessive heat.
Safety The medicine must be kept out of the sight and reach of children.

Disposal Instructions

Official disposal rules require that unused or expired Tiadis must not be discarded into household trash or flushed down the sink or toilet. The product must be returned to a pharmacist or an authorized local drug take-back program for proper pharmaceutical waste handling. Using the medicine past the expiration date on the package is prohibited.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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