PALBOCICLIB

72/100 · Elevated

Manufactured by Pfizer Laboratories Div Pfizer Inc

Moderate Safety Concerns with Palbociclib: Focus on Hematological and Gastrointestinal Reactions

205,909 FDA adverse event reports analyzed

Last updated: 2026-05-12

About PALBOCICLIB

PALBOCICLIB is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Pfizer Laboratories Div Pfizer Inc. Based on analysis of 205,909 FDA adverse event reports, PALBOCICLIB has a safety score of 72 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 PALBOCICLIB include FATIGUE, WHITE BLOOD CELL COUNT DECREASED, NEOPLASM PROGRESSION, NAUSEA, DEATH. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for PALBOCICLIB.

AI Safety Analysis

Palbociclib has a safety concern score of 72 out of 100, placing it in the elevated concern category based on analysis of FDA adverse event data. The FDA has received approximately 205,909 adverse event reports for this medication, which is primarily manufactured by Pfizer Laboratories Div Pfizer Inc.

The most commonly reported adverse events include Fatigue, White Blood Cell Count Decreased, Neoplasm Progression. Of classified reports, 52.4% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Palbociclib reports show a high incidence of hematological adverse events such as neutropenia and anemia.

Gastrointestinal symptoms like nausea and diarrhea are also frequently reported. Serious adverse events, particularly related to disease progression and death, are concerning.

Patients taking Palbociclib should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Palbociclib can cause significant hematological side effects, including neutropenia and anemia, and patients should be monitored closely. Drug interactions are not specifically warned against, but caution is advised due to its impact on blood cell co This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 72/100

Palbociclib received a safety concern score of 72/100 (elevated concern). This is based on a 52.4% serious event ratio across 93,575 classified reports. The score accounts for 205,909 total adverse event reports and 100 distinct reaction types. This elevated score indicates a notable proportion of serious adverse events and warrants careful monitoring.

Top Adverse Reactions

FATIGUE15,580 reports
WHITE BLOOD CELL COUNT DECREASED11,337 reports
NEOPLASM PROGRESSION10,628 reports
NAUSEA8,459 reports
DEATH7,658 reports
NEUTROPENIA6,613 reports
ALOPECIA6,311 reports
DIARRHOEA5,868 reports
ASTHENIA3,723 reports
OFF LABEL USE3,628 reports
DECREASED APPETITE3,454 reports
PAIN3,445 reports
MALAISE3,327 reports
DYSPNOEA3,235 reports
VOMITING3,114 reports
ARTHRALGIA3,065 reports
STOMATITIS2,783 reports
CONSTIPATION2,764 reports
HEADACHE2,741 reports
DIZZINESS2,506 reports
RASH2,308 reports
COUGH2,299 reports
DISEASE PROGRESSION2,264 reports
PLATELET COUNT DECREASED2,259 reports
MALIGNANT NEOPLASM PROGRESSION2,253 reports
NEUTROPHIL COUNT DECREASED2,245 reports
ANAEMIA2,237 reports
PRODUCT DOSE OMISSION ISSUE2,176 reports
FULL BLOOD COUNT DECREASED1,970 reports
WEIGHT DECREASED1,958 reports
HOT FLUSH1,924 reports
BACK PAIN1,849 reports
RED BLOOD CELL COUNT DECREASED1,816 reports
PYREXIA1,754 reports
PRURITUS1,697 reports
PAIN IN EXTREMITY1,692 reports
HAEMOGLOBIN DECREASED1,673 reports
PRODUCT USE ISSUE1,575 reports
PNEUMONIA1,502 reports
COVID 191,497 reports
LEUKOPENIA1,460 reports
INSOMNIA1,450 reports
THROMBOCYTOPENIA1,436 reports
DRY SKIN1,422 reports
NASOPHARYNGITIS1,368 reports
NEUROPATHY PERIPHERAL1,365 reports
MEMORY IMPAIRMENT1,336 reports
ILLNESS1,335 reports
ABDOMINAL DISCOMFORT1,328 reports
EPISTAXIS1,298 reports
FALL1,291 reports
BONE PAIN1,256 reports
URINARY TRACT INFECTION1,254 reports
FEELING ABNORMAL1,218 reports
DRUG INEFFECTIVE1,203 reports
BLOOD COUNT ABNORMAL1,152 reports
FULL BLOOD COUNT ABNORMAL1,152 reports
PERIPHERAL SWELLING1,089 reports
CONDITION AGGRAVATED1,069 reports
METASTASES TO BONE1,065 reports
ABDOMINAL PAIN UPPER1,033 reports
BREAST CANCER METASTATIC1,021 reports
ANXIETY1,016 reports
HYPOAESTHESIA975 reports
WEIGHT INCREASED966 reports
BONE MARROW FAILURE953 reports
DEHYDRATION904 reports
PRODUCT USE IN UNAPPROVED INDICATION901 reports
HYPOACUSIS890 reports
GAIT DISTURBANCE888 reports
MYALGIA887 reports
TUMOUR MARKER INCREASED868 reports
SOMNOLENCE863 reports
MUSCLE SPASMS849 reports
PLEURAL EFFUSION846 reports
INFECTION839 reports
DEPRESSION832 reports
DYSPEPSIA807 reports
PARAESTHESIA798 reports
DYSPHAGIA787 reports
ORAL PAIN784 reports
ABDOMINAL PAIN779 reports
OROPHARYNGEAL PAIN725 reports
METASTASES TO LIVER724 reports
CONFUSIONAL STATE712 reports
BREAST CANCER709 reports
SECOND PRIMARY MALIGNANCY682 reports
CHILLS673 reports
PANCYTOPENIA643 reports
PULMONARY EMBOLISM641 reports
THROMBOSIS639 reports
CEREBROVASCULAR ACCIDENT633 reports
DYSGEUSIA632 reports
INFLUENZA628 reports
DRY MOUTH622 reports
CONTUSION611 reports
PRODUCT DOSE OMISSION IN ERROR607 reports
HYPERTENSION606 reports
CHEST PAIN601 reports
THERAPY CESSATION601 reports

Key Safety Signals

  • Neutropenia and anemia are the most common hematological reactions.
  • Nausea and diarrhea are the most frequent gastrointestinal reactions.
  • Disease progression and death are reported as serious adverse events.

Patient Demographics

Adverse event reports by sex: Female: 86,509, Male: 2,243, Unknown: 50. The most frequently reported age groups are age 65 (2,532 reports), age 70 (2,473 reports), age 69 (2,405 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 93,575 classified reports for PALBOCICLIB:

  • Serious: 49,052 reports (52.4%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 44,523 reports (47.6%)
Serious 52.4%Non-Serious 47.6%

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

Female86,509 (97.4%)
Male2,243 (2.5%)
Unknown50 (0.1%)

Reports by Age

Age 652,532 reports
Age 702,473 reports
Age 692,405 reports
Age 662,401 reports
Age 732,397 reports
Age 672,390 reports
Age 682,384 reports
Age 642,367 reports
Age 632,294 reports
Age 722,290 reports
Age 752,260 reports
Age 712,247 reports
Age 742,241 reports
Age 622,217 reports
Age 612,195 reports
Age 602,069 reports
Age 762,046 reports
Age 771,980 reports
Age 591,876 reports
Age 781,852 reports

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

Drug Interactions & Warnings

Palbociclib can cause significant hematological side effects, including neutropenia and anemia, and patients should be monitored closely. Drug interactions are not specifically warned against, but caution is advised due to its impact on blood cell co

What You Should Know

If you are taking Palbociclib, here are important things to know. The most commonly reported side effects include fatigue, white blood cell count decreased, neoplasm progression, nausea, death. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Patients should report any signs of infection, such as fever or chills, to their healthcare provider immediately. Regular blood tests are recommended to monitor for hematological 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 continues to monitor Palbociclib for safety, and updates will be provided as necessary. Healthcare providers should report any adverse events to the FDA's MedWatch program.

Frequently Asked Questions

How many adverse event reports has the FDA received for Palbociclib?

The FDA has received approximately 205,909 adverse event reports associated with Palbociclib. 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 Palbociclib?

The most frequently reported adverse events for Palbociclib include Fatigue, White Blood Cell Count Decreased, Neoplasm Progression, Nausea, Death. By volume, the top reported reactions are: Fatigue (15,580 reports), White Blood Cell Count Decreased (11,337 reports), Neoplasm Progression (10,628 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Palbociclib.

What percentage of Palbociclib adverse event reports are serious?

Out of 93,575 classified reports, 49,052 (52.4%) were classified as serious and 44,523 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 Palbociclib (by sex)?

Adverse event reports for Palbociclib break down by patient sex as follows: Female: 86,509, Male: 2,243, Unknown: 50. 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 Palbociclib?

The most frequently reported age groups for Palbociclib adverse events are: age 65: 2,532 reports, age 70: 2,473 reports, age 69: 2,405 reports, age 66: 2,401 reports, age 73: 2,397 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 Palbociclib?

The primary manufacturer associated with Palbociclib adverse event reports is Pfizer Laboratories Div Pfizer 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 Palbociclib?

Beyond the most common reactions, other reported adverse events for Palbociclib include: Neutropenia, Alopecia, Diarrhoea, Asthenia, Off Label Use. 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 Palbociclib?

You can report adverse events from Palbociclib 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 Palbociclib's safety score and what does it mean?

Palbociclib has a safety concern score of 72 out of 100 (elevated 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. Palbociclib reports show a high incidence of hematological adverse events such as neutropenia and anemia.

What are the key safety signals for Palbociclib?

Key safety signals identified in Palbociclib's adverse event data include: Neutropenia and anemia are the most common hematological reactions.. Nausea and diarrhea are the most frequent gastrointestinal reactions.. Disease progression and death are reported as serious adverse events.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Palbociclib interact with other drugs?

Palbociclib can cause significant hematological side effects, including neutropenia and anemia, and patients should be monitored closely. Drug interactions are not specifically warned against, but caution is advised due to its impact on blood cell co Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Palbociclib.

What should patients know before taking Palbociclib?

Patients should report any signs of infection, such as fever or chills, to their healthcare provider immediately. Regular blood tests are recommended to monitor for hematological side effects.

Are Palbociclib side effects well-documented?

Palbociclib has 205,909 adverse event reports on file with the FDA. Gastrointestinal symptoms like nausea and diarrhea are also frequently reported. The volume of reports for Palbociclib reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Palbociclib?

The FDA continues to monitor Palbociclib for safety, and updates will be provided as necessary. Healthcare providers should report any adverse events to the FDA's MedWatch program. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

Related Drugs

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

PalbociclibPfizerMedWatch
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.