LETROZOLE TABLETS

85/100 · Critical

Manufactured by Avet Pharmaceuticals Inc.

High Safety Concerns with Letrozole Tablets, Particularly for Serious Reactions

116,600 FDA adverse event reports analyzed

Last updated: 2026-05-12

About LETROZOLE TABLETS

LETROZOLE TABLETS is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Avet Pharmaceuticals Inc.. Based on analysis of 116,600 FDA adverse event reports, LETROZOLE TABLETS has a safety score of 85 out of 100. This score indicates a relatively favorable safety profile, with fewer or less severe adverse events compared to many other tracked medications. The most commonly reported adverse reactions for LETROZOLE TABLETS include FATIGUE, NEUTROPENIA, NAUSEA, DIARRHOEA, MALIGNANT NEOPLASM PROGRESSION. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for LETROZOLE TABLETS.

AI Safety Analysis

Letrozole Tablets has a safety concern score of 85 out of 100, placing it in the high concern category based on analysis of FDA adverse event data. The FDA has received approximately 116,600 adverse event reports for this medication, which is primarily manufactured by Avet Pharmaceuticals Inc..

The most commonly reported adverse events include Fatigue, Neutropenia, Nausea. Of classified reports, 79.7% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Frequent serious reactions such as neoplasms progression and death indicate significant safety concerns.

Neutropenia and leukopenia are common, highlighting the risk of severe hematological adverse events. A wide range of reactions, including cardiovascular and respiratory issues, suggests a broad safety profile.

Patients taking Letrozole Tablets should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Letrozole tablets may interact with other drugs, potentially exacerbating hematological and other adverse effects. Warnings include the risk of osteonecrosis of the jaw and pulmonary embolism. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 85/100

Letrozole Tablets received a safety concern score of 85/100 (high concern). This is based on a 79.7% serious event ratio across 45,824 classified reports. The score accounts for 116,600 total adverse event reports and 100 distinct reaction types. This high score reflects a significant proportion of serious adverse events in the reporting data.

Top Adverse Reactions

FATIGUE5,815 reports
NEUTROPENIA4,301 reports
NAUSEA4,210 reports
DIARRHOEA3,666 reports
MALIGNANT NEOPLASM PROGRESSION3,381 reports
WHITE BLOOD CELL COUNT DECREASED3,142 reports
ARTHRALGIA2,821 reports
ALOPECIA2,742 reports
NEOPLASM PROGRESSION2,450 reports
DYSPNOEA2,238 reports
ASTHENIA2,220 reports
PAIN2,122 reports
VOMITING2,079 reports
DECREASED APPETITE1,897 reports
OFF LABEL USE1,824 reports
HEADACHE1,803 reports
DEATH1,797 reports
METASTASES TO BONE1,763 reports
ANAEMIA1,718 reports
DIZZINESS1,679 reports
DISEASE PROGRESSION1,648 reports
MALAISE1,636 reports
BREAST CANCER METASTATIC1,600 reports
COUGH1,514 reports
PYREXIA1,503 reports
DRUG INEFFECTIVE1,352 reports
PRURITUS1,313 reports
BREAST CANCER1,299 reports
CONSTIPATION1,279 reports
METASTASES TO LIVER1,268 reports
WEIGHT DECREASED1,237 reports
BACK PAIN1,234 reports
PAIN IN EXTREMITY1,231 reports
RASH1,223 reports
LEUKOPENIA1,211 reports
HOT FLUSH1,164 reports
INSOMNIA1,037 reports
THROMBOCYTOPENIA1,036 reports
FALL1,033 reports
NEUTROPHIL COUNT DECREASED999 reports
BONE PAIN995 reports
ABDOMINAL PAIN977 reports
MYALGIA959 reports
PLATELET COUNT DECREASED914 reports
PNEUMONIA909 reports
HAEMOGLOBIN DECREASED897 reports
URINARY TRACT INFECTION885 reports
ABDOMINAL PAIN UPPER828 reports
NEUROPATHY PERIPHERAL818 reports
STOMATITIS804 reports
PLEURAL EFFUSION803 reports
ANXIETY758 reports
GENERAL PHYSICAL HEALTH DETERIORATION726 reports
COVID 19722 reports
DEPRESSION688 reports
DRY SKIN688 reports
HYPERTENSION678 reports
ALANINE AMINOTRANSFERASE INCREASED656 reports
NASOPHARYNGITIS655 reports
FEELING ABNORMAL654 reports
METASTASES TO LUNG645 reports
ASCITES625 reports
ASPARTATE AMINOTRANSFERASE INCREASED625 reports
RED BLOOD CELL COUNT DECREASED623 reports
WEIGHT INCREASED618 reports
GAIT DISTURBANCE612 reports
PRODUCT USE IN UNAPPROVED INDICATION611 reports
CONDITION AGGRAVATED600 reports
ABDOMINAL DISCOMFORT598 reports
CHILLS592 reports
SOMNOLENCE590 reports
ACUTE KIDNEY INJURY588 reports
BLOOD CREATININE INCREASED588 reports
PERIPHERAL SWELLING588 reports
PARAESTHESIA553 reports
PULMONARY EMBOLISM545 reports
BLOOD PRESSURE INCREASED541 reports
MUSCLE SPASMS538 reports
ELECTROCARDIOGRAM QT PROLONGED525 reports
DRUG INTOLERANCE517 reports
OSTEONECROSIS OF JAW516 reports
OEDEMA PERIPHERAL513 reports
PRODUCT DOSE OMISSION ISSUE506 reports
MEMORY IMPAIRMENT502 reports
DYSPEPSIA497 reports
EPISTAXIS497 reports
SEPSIS495 reports
HYPOAESTHESIA493 reports
VISION BLURRED490 reports
HEPATOTOXICITY484 reports
CHEST PAIN470 reports
TACHYCARDIA452 reports
VISUAL IMPAIRMENT446 reports
DEHYDRATION444 reports
FULL BLOOD COUNT DECREASED442 reports
SYNCOPE440 reports
PRODUCT USE ISSUE432 reports
METASTASES TO LYMPH NODES428 reports
ERYTHEMA417 reports
ILLNESS415 reports

Key Safety Signals

  • Neoplastic progression and death are key safety signals, indicating potential risks for serious adverse outcomes.
  • Neutropenia and leukopenia are frequent, suggesting a high risk of hematological toxicity.
  • A diverse range of reactions, including cardiovascular and respiratory issues, indicates a broad safety profile.

Patient Demographics

Adverse event reports by sex: Female: 41,999, Male: 665, Unknown: 36. The most frequently reported age groups are age 70 (1,030 reports), age 63 (986 reports), age 65 (979 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 45,824 classified reports for LETROZOLE TABLETS:

  • Serious: 36,512 reports (79.7%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 9,312 reports (20.3%)
Serious 79.7%Non-Serious 20.3%

The FDA classifies an adverse event as “serious” if it results in death, hospitalization, disability, congenital anomaly, or requires intervention to prevent permanent damage.

Demographics Breakdown

Reports by Sex

Female41,999 (98.4%)
Male665 (1.6%)
Unknown36 (0.1%)

Reports by Age

Age 701,030 reports
Age 63986 reports
Age 65979 reports
Age 61977 reports
Age 69964 reports
Age 62961 reports
Age 68948 reports
Age 73937 reports
Age 60934 reports
Age 67930 reports
Age 64920 reports
Age 66918 reports
Age 71884 reports
Age 58858 reports
Age 72855 reports
Age 75830 reports
Age 59801 reports
Age 57771 reports
Age 74745 reports
Age 76718 reports

Demographics reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.

Drug Interactions & Warnings

Letrozole tablets may interact with other drugs, potentially exacerbating hematological and other adverse effects. Warnings include the risk of osteonecrosis of the jaw and pulmonary embolism.

What You Should Know

If you are taking Letrozole Tablets, here are important things to know. The most commonly reported side effects include fatigue, neutropenia, nausea, diarrhoea, malignant neoplasm progression. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Monitor for signs of serious adverse reactions such as neoplastic progression and hematological issues. Be aware of potential drug interactions and consult a healthcare provider if experiencing any side effects. If you experience a serious adverse reaction, seek emergency medical attention immediately or call 911. You can report side effects to the FDA's MedWatch program at 1-800-FDA-1088.

Regulatory Context

The FDA closely monitors adverse events for Letrozole tablets, and regulatory actions may be taken based on ongoing safety assessments.

Frequently Asked Questions

How many adverse event reports has the FDA received for Letrozole Tablets?

The FDA has received approximately 116,600 adverse event reports associated with Letrozole Tablets. These reports come from healthcare professionals, consumers, and manufacturers through the FDA Adverse Event Reporting System (FAERS). Note that the number of reports does not directly indicate the frequency of side effects, as adverse events are voluntarily reported and may be underrepresented.

What are the most commonly reported side effects of Letrozole Tablets?

The most frequently reported adverse events for Letrozole Tablets include Fatigue, Neutropenia, Nausea, Diarrhoea, Malignant Neoplasm Progression. By volume, the top reported reactions are: Fatigue (5,815 reports), Neutropenia (4,301 reports), Nausea (4,210 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Letrozole Tablets.

What percentage of Letrozole Tablets adverse event reports are serious?

Out of 45,824 classified reports, 36,512 (79.7%) were classified as serious and 9,312 as non-serious. The FDA classifies an event as "serious" if it results in death, hospitalization, disability, or other medically significant outcomes. A higher serious-event ratio warrants closer attention but does not necessarily mean the drug is unsafe.

Who reports adverse events for Letrozole Tablets (by sex)?

Adverse event reports for Letrozole Tablets break down by patient sex as follows: Female: 41,999, Male: 665, Unknown: 36. This distribution reflects reporting patterns rather than actual risk differences between groups. Reporting rates can be influenced by prescribing patterns, disease demographics, and reporting behavior.

What age groups report the most side effects for Letrozole Tablets?

The most frequently reported age groups for Letrozole Tablets adverse events are: age 70: 1,030 reports, age 63: 986 reports, age 65: 979 reports, age 61: 977 reports, age 69: 964 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.

Who manufactures Letrozole Tablets?

The primary manufacturer associated with Letrozole Tablets adverse event reports is Avet Pharmaceuticals Inc.. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.

What other side effects have been reported for Letrozole Tablets?

Beyond the most common reactions, other reported adverse events for Letrozole Tablets include: White Blood Cell Count Decreased, Arthralgia, Alopecia, Neoplasm Progression, Dyspnoea. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.

How do I report a side effect from Letrozole Tablets?

You can report adverse events from Letrozole Tablets to the FDA through their MedWatch program at www.fda.gov/medwatch, by calling 1-800-FDA-1088, or by completing Form FDA 3500. Healthcare professionals, consumers, and manufacturers can all submit reports. Reporting helps the FDA monitor drug safety after approval.

What is Letrozole Tablets's safety score and what does it mean?

Letrozole Tablets has a safety concern score of 85 out of 100 (high concern). This score is calculated from the ratio of serious to non-serious adverse events, the diversity of reported reactions, and the overall volume of reports relative to usage. Frequent serious reactions such as neoplasms progression and death indicate significant safety concerns.

What are the key safety signals for Letrozole Tablets?

Key safety signals identified in Letrozole Tablets's adverse event data include: Neoplastic progression and death are key safety signals, indicating potential risks for serious adverse outcomes.. Neutropenia and leukopenia are frequent, suggesting a high risk of hematological toxicity.. A diverse range of reactions, including cardiovascular and respiratory issues, indicates a broad safety profile.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Letrozole Tablets interact with other drugs?

Letrozole tablets may interact with other drugs, potentially exacerbating hematological and other adverse effects. Warnings include the risk of osteonecrosis of the jaw and pulmonary embolism. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Letrozole Tablets.

What should patients know before taking Letrozole Tablets?

Monitor for signs of serious adverse reactions such as neoplastic progression and hematological issues. Be aware of potential drug interactions and consult a healthcare provider if experiencing any side effects.

Are Letrozole Tablets side effects well-documented?

Letrozole Tablets has 116,600 adverse event reports on file with the FDA. Neutropenia and leukopenia are common, highlighting the risk of severe hematological adverse events. The volume of reports for Letrozole Tablets reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Letrozole Tablets?

The FDA closely monitors adverse events for Letrozole tablets, and regulatory actions may be taken based on ongoing safety assessments. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

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Related Drugs

Drugs related to LETROZOLE TABLETS based on therapeutic use, drug class, or shared indications:

Osteonecrosis of the jawPulmonary embolismHematological toxicityNeoplastic progressionDeath
Important Disclaimer: This content is generated by AI analysis of FDA adverse event reports and is provided for informational purposes only. It is not medical advice. Adverse event reports submitted to the FDA do not prove that a medication caused the reported side effect. Always consult your healthcare provider before starting, stopping, or changing any medication. If you experience a serious side effect, contact your doctor or call 911 immediately.