85/100 · Critical
Manufactured by Mylan Institutional LLC
Allopurinol Adverse Events: High Serious Reaction Rate
274,886 FDA adverse event reports analyzed
Last updated: 2026-05-12
ALLOPURINOL is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Mylan Institutional LLC. Based on analysis of 274,886 FDA adverse event reports, ALLOPURINOL 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 ALLOPURINOL include DIARRHOEA, FATIGUE, DYSPNOEA, NAUSEA, DEATH. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for ALLOPURINOL.
Allopurinol 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 274,886 adverse event reports for this medication, which is primarily manufactured by Mylan Institutional Llc.
The most commonly reported adverse events include Diarrhoea, Fatigue, Dyspnoea. Of classified reports, 82.2% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Allopurinol has a high rate of serious adverse events, particularly kidney and respiratory issues.
The most common reactions include diarrhea, fatigue, and dyspnea, but these are often non-serious. Drug interactions and renal impairment are significant safety concerns.
Patients taking Allopurinol should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Allopurinol can interact with other drugs, leading to adverse effects. Warnings include interactions with sulfonamides and other drugs that may cause severe reactions. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.
Allopurinol received a safety concern score of 85/100 (high concern). This is based on a 82.2% serious event ratio across 150,955 classified reports. The score accounts for 274,886 total adverse event reports and 100 distinct reaction types. This high score reflects a significant proportion of serious adverse events in the reporting data.
Adverse event reports by sex: Male: 89,867, Female: 49,072, Unknown: 448. The most frequently reported age groups are age 72 (3,788 reports), age 73 (3,777 reports), age 74 (3,700 reports). These demographics reflect reporting patterns and may not represent the full patient population.
Out of 150,955 classified reports for ALLOPURINOL:
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 reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.
Allopurinol can interact with other drugs, leading to adverse effects. Warnings include interactions with sulfonamides and other drugs that may cause severe reactions.
If you are taking Allopurinol, here are important things to know. The most commonly reported side effects include diarrhoea, fatigue, dyspnoea, nausea, 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 kidney and respiratory issues, especially in elderly patients. Be cautious of drug interactions and follow prescribed dosages. 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.
The FDA closely monitors allopurinol due to its high rate of serious adverse events, particularly in older adults.
The FDA has received approximately 274,886 adverse event reports associated with Allopurinol. 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.
The most frequently reported adverse events for Allopurinol include Diarrhoea, Fatigue, Dyspnoea, Nausea, Death. By volume, the top reported reactions are: Diarrhoea (8,421 reports), Fatigue (7,967 reports), Dyspnoea (7,658 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Allopurinol.
Out of 150,955 classified reports, 124,150 (82.2%) were classified as serious and 26,805 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.
Adverse event reports for Allopurinol break down by patient sex as follows: Male: 89,867, Female: 49,072, Unknown: 448. 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.
The most frequently reported age groups for Allopurinol adverse events are: age 72: 3,788 reports, age 73: 3,777 reports, age 74: 3,700 reports, age 71: 3,652 reports, age 76: 3,557 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.
The primary manufacturer associated with Allopurinol adverse event reports is Mylan Institutional Llc. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.
Beyond the most common reactions, other reported adverse events for Allopurinol include: Acute Kidney Injury, Off Label Use, Pyrexia, Pneumonia, Asthenia. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.
You can report adverse events from Allopurinol 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.
Allopurinol 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. Allopurinol has a high rate of serious adverse events, particularly kidney and respiratory issues.
Key safety signals identified in Allopurinol's adverse event data include: Acute kidney injury and renal failure are frequent and serious adverse events.. Respiratory issues such as pneumonia and dyspnea are also common.. Drug interactions and ineffective drug performance are reported.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.
Allopurinol can interact with other drugs, leading to adverse effects. Warnings include interactions with sulfonamides and other drugs that may cause severe reactions. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Allopurinol.
Monitor for signs of kidney and respiratory issues, especially in elderly patients. Be cautious of drug interactions and follow prescribed dosages.
Allopurinol has 274,886 adverse event reports on file with the FDA. The most common reactions include diarrhea, fatigue, and dyspnea, but these are often non-serious. The volume of reports for Allopurinol reflects both the drug's usage level and the vigilance of the reporting community.
The FDA closely monitors allopurinol due to its high rate of serious adverse events, particularly in older adults. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.
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