CILOSTAZOL

72/100 · Elevated

Manufactured by Apotex Corp.

Cilostazol Adverse Events: High Serious Reaction Rate and Diverse Safety Profile

9,564 FDA adverse event reports analyzed

Last updated: 2026-05-12

About CILOSTAZOL

CILOSTAZOL is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Apotex Corp.. Based on analysis of 9,564 FDA adverse event reports, CILOSTAZOL 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 CILOSTAZOL include DIARRHOEA, FALL, PNEUMONIA, DRUG INEFFECTIVE, DEATH. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for CILOSTAZOL.

AI Safety Analysis

Cilostazol 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 9,564 adverse event reports for this medication, which is primarily manufactured by Apotex Corp..

The most commonly reported adverse events include Diarrhoea, Fall, Pneumonia. Of classified reports, 81.9% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Cilostazol reports show a high serious reaction rate, with 81.9% of reactions being serious.

The most common reactions include gastrointestinal issues, respiratory problems, and cardiovascular events. Drug interactions and renal impairment are significant safety concerns.

Patients taking Cilostazol should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Cilostazol can cause renal impairment and drug interactions, which should be monitored, especially in patients with pre-existing renal conditions or taking other medications. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 72/100

Cilostazol received a safety concern score of 72/100 (elevated concern). This is based on a 81.9% serious event ratio across 5,990 classified reports. The score accounts for 9,564 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

DIARRHOEA303 reports
FALL231 reports
PNEUMONIA230 reports
DRUG INEFFECTIVE229 reports
DEATH217 reports
DYSPNOEA209 reports
NAUSEA206 reports
OFF LABEL USE204 reports
ANAEMIA191 reports
ASTHENIA185 reports
FATIGUE182 reports
DIZZINESS181 reports
VOMITING179 reports
PAIN IN EXTREMITY171 reports
PAIN159 reports
RENAL FAILURE159 reports
HEADACHE152 reports
DECREASED APPETITE149 reports
ACUTE KIDNEY INJURY143 reports
MALAISE142 reports
DRUG INTERACTION141 reports
CHRONIC KIDNEY DISEASE137 reports
GASTROINTESTINAL HAEMORRHAGE130 reports
PYREXIA126 reports
HYPOTENSION125 reports
WEIGHT DECREASED124 reports
CEREBRAL INFARCTION114 reports
HYPERTENSION112 reports
MYOCARDIAL INFARCTION111 reports
PRURITUS108 reports
URINARY TRACT INFECTION102 reports
CONSTIPATION99 reports
DEHYDRATION99 reports
CARDIAC FAILURE96 reports
RENAL IMPAIRMENT96 reports
RASH94 reports
CONDITION AGGRAVATED93 reports
GAIT DISTURBANCE93 reports
CEREBROVASCULAR ACCIDENT91 reports
ATRIAL FIBRILLATION89 reports
BLOOD GLUCOSE INCREASED88 reports
CARDIAC FAILURE CONGESTIVE88 reports
CHEST PAIN88 reports
ARTHRALGIA85 reports
LOSS OF CONSCIOUSNESS83 reports
COUGH82 reports
BACK PAIN79 reports
HAEMOGLOBIN DECREASED79 reports
INTERSTITIAL LUNG DISEASE79 reports
ANXIETY77 reports
OEDEMA PERIPHERAL77 reports
BLOOD PRESSURE DECREASED76 reports
TACHYCARDIA76 reports
SOMNOLENCE72 reports
INSOMNIA71 reports
ABDOMINAL PAIN67 reports
HEPATIC FUNCTION ABNORMAL67 reports
CONFUSIONAL STATE64 reports
SEPSIS63 reports
CARDIAC ARREST60 reports
HYPERHIDROSIS60 reports
MUSCULAR WEAKNESS60 reports
BLOOD PRESSURE INCREASED59 reports
CEREBRAL HAEMORRHAGE59 reports
HYPOGLYCAEMIA59 reports
DEPRESSION58 reports
HYPOAESTHESIA58 reports
HAEMORRHAGE57 reports
PLEURAL EFFUSION56 reports
VISION BLURRED56 reports
ABDOMINAL PAIN UPPER55 reports
ERYTHEMA55 reports
FEELING ABNORMAL55 reports
MUSCLE SPASMS55 reports
PALPITATIONS55 reports
PRODUCT DOSE OMISSION ISSUE53 reports
TREMOR53 reports
DIABETES MELLITUS52 reports
ACUTE MYOCARDIAL INFARCTION51 reports
PRODUCT USE IN UNAPPROVED INDICATION51 reports
ALANINE AMINOTRANSFERASE INCREASED50 reports
PERIPHERAL SWELLING50 reports
THROMBOSIS50 reports
WEIGHT INCREASED50 reports
PLATELET COUNT DECREASED49 reports
ASPARTATE AMINOTRANSFERASE INCREASED48 reports
DYSPHAGIA48 reports
END STAGE RENAL DISEASE48 reports
HYPERGLYCAEMIA46 reports
PERIPHERAL ARTERIAL OCCLUSIVE DISEASE46 reports
WHITE BLOOD CELL COUNT DECREASED46 reports
BLOOD CREATININE INCREASED44 reports
CARDIO RESPIRATORY ARREST44 reports
CONTUSION44 reports
PNEUMONIA ASPIRATION44 reports
RHABDOMYOLYSIS44 reports
SYNCOPE44 reports
CHEST DISCOMFORT43 reports
CHRONIC OBSTRUCTIVE PULMONARY DISEASE43 reports
HAEMATOCHEZIA43 reports

Key Safety Signals

  • High percentage of serious reactions (81.9%)
  • Diverse range of reactions, including gastrointestinal, respiratory, and cardiovascular issues
  • Renal impairment and drug interactions are frequent

Patient Demographics

Adverse event reports by sex: Male: 3,302, Female: 2,282, Unknown: 15. The most frequently reported age groups are age 77 (189 reports), age 72 (167 reports), age 80 (161 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 5,990 classified reports for CILOSTAZOL:

  • Serious: 4,904 reports (81.9%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 1,086 reports (18.1%)
Serious 81.9%Non-Serious 18.1%

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

Male3,302 (59.0%)
Female2,282 (40.8%)
Unknown15 (0.3%)

Reports by Age

Age 77189 reports
Age 72167 reports
Age 80161 reports
Age 78160 reports
Age 70151 reports
Age 71149 reports
Age 74149 reports
Age 79149 reports
Age 73143 reports
Age 69142 reports
Age 81138 reports
Age 76136 reports
Age 64129 reports
Age 67123 reports
Age 75122 reports
Age 68121 reports
Age 83120 reports
Age 84119 reports
Age 65118 reports
Age 66117 reports

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

Drug Interactions & Warnings

Cilostazol can cause renal impairment and drug interactions, which should be monitored, especially in patients with pre-existing renal conditions or taking other medications.

What You Should Know

If you are taking Cilostazol, here are important things to know. The most commonly reported side effects include diarrhoea, fall, pneumonia, drug ineffective, death. 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 renal impairment, especially in elderly patients. Be cautious of potential drug interactions, particularly with other anticoagulants or antiplatelet agents. 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 cilostazol safety, and regulatory actions may be taken based on ongoing data analysis.

Frequently Asked Questions

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

The FDA has received approximately 9,564 adverse event reports associated with Cilostazol. 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 Cilostazol?

The most frequently reported adverse events for Cilostazol include Diarrhoea, Fall, Pneumonia, Drug Ineffective, Death. By volume, the top reported reactions are: Diarrhoea (303 reports), Fall (231 reports), Pneumonia (230 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Cilostazol.

What percentage of Cilostazol adverse event reports are serious?

Out of 5,990 classified reports, 4,904 (81.9%) were classified as serious and 1,086 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 Cilostazol (by sex)?

Adverse event reports for Cilostazol break down by patient sex as follows: Male: 3,302, Female: 2,282, Unknown: 15. 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 Cilostazol?

The most frequently reported age groups for Cilostazol adverse events are: age 77: 189 reports, age 72: 167 reports, age 80: 161 reports, age 78: 160 reports, age 70: 151 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 Cilostazol?

The primary manufacturer associated with Cilostazol adverse event reports is Apotex Corp.. 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 Cilostazol?

Beyond the most common reactions, other reported adverse events for Cilostazol include: Dyspnoea, Nausea, Off Label Use, Anaemia, Asthenia. 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 Cilostazol?

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

Cilostazol 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. Cilostazol reports show a high serious reaction rate, with 81.9% of reactions being serious.

What are the key safety signals for Cilostazol?

Key safety signals identified in Cilostazol's adverse event data include: High percentage of serious reactions (81.9%). Diverse range of reactions, including gastrointestinal, respiratory, and cardiovascular issues. Renal impairment and drug interactions are frequent. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Cilostazol interact with other drugs?

Cilostazol can cause renal impairment and drug interactions, which should be monitored, especially in patients with pre-existing renal conditions or taking other medications. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Cilostazol.

What should patients know before taking Cilostazol?

Monitor for signs of renal impairment, especially in elderly patients. Be cautious of potential drug interactions, particularly with other anticoagulants or antiplatelet agents.

Are Cilostazol side effects well-documented?

Cilostazol has 9,564 adverse event reports on file with the FDA. The most common reactions include gastrointestinal issues, respiratory problems, and cardiovascular events. The volume of reports for Cilostazol reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Cilostazol?

The FDA continues to monitor cilostazol safety, and regulatory actions may be taken based on ongoing data analysis. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

Related Drugs

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

WarfarinAspirinDipyridamole
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.