65/100 · Elevated
Manufactured by AbbVie Inc.
Levotroxine Sodium Adverse Events: Moderate Safety Concerns
665,570 FDA adverse event reports analyzed
Last updated: 2026-05-12
LEVOTHYROXINE SODIUM is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by AbbVie Inc.. Based on analysis of 665,570 FDA adverse event reports, LEVOTHYROXINE SODIUM has a safety score of 65 out of 100. This moderate score indicates a notable volume of adverse event reports that patients and providers should be aware of. The most commonly reported adverse reactions for LEVOTHYROXINE SODIUM include FATIGUE, NAUSEA, DRUG INEFFECTIVE, HEADACHE, DIARRHOEA. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for LEVOTHYROXINE SODIUM.
Levothyroxine Sodium has a safety concern score of 65 out of 100, placing it in the elevated concern category based on analysis of FDA adverse event data. The FDA has received approximately 665,570 adverse event reports for this medication, which is primarily manufactured by Abbvie Inc..
The most commonly reported adverse events include Fatigue, Nausea, Drug Ineffective. Of classified reports, 60.1% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Fatigue and nausea are the most common adverse reactions reported.
Serious adverse events, such as death and pneumonia, account for 60.1% of total reports. Drug ineffectiveness and fall are also frequently reported. The majority of reports are from older adults, with the highest count from those aged 65-77.
Patients taking Levothyroxine Sodium should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Levotroxine sodium can interact with other thyroid medications and may cause hypertension or hypotension. Patients should be monitored for these conditions and informed of potential drug interactions. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.
Levothyroxine Sodium received a safety concern score of 65/100 (elevated concern). This is based on a 60.1% serious event ratio across 304,316 classified reports. The score accounts for 665,570 total adverse event reports and 100 distinct reaction types. This elevated score indicates a notable proportion of serious adverse events and warrants careful monitoring.
Adverse event reports by sex: Female: 230,799, Male: 54,803, Unknown: 433. The most frequently reported age groups are age 65 (5,296 reports), age 66 (4,883 reports), age 70 (4,865 reports). These demographics reflect reporting patterns and may not represent the full patient population.
Out of 304,316 classified reports for LEVOTHYROXINE SODIUM:
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.
Levotroxine sodium can interact with other thyroid medications and may cause hypertension or hypotension. Patients should be monitored for these conditions and informed of potential drug interactions.
If you are taking Levothyroxine Sodium, here are important things to know. The most commonly reported side effects include fatigue, nausea, drug ineffective, headache, diarrhoea. 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 hypothyroidism or hyperthyroidism, especially in older adults. Inform your healthcare provider about all medications and supplements you are taking to avoid potential drug interactions. 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 continues to monitor Levotroxine sodium for safety. Healthcare providers should report any adverse events to the FDA's MedWatch program.
The FDA has received approximately 665,570 adverse event reports associated with Levothyroxine Sodium. 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 Levothyroxine Sodium include Fatigue, Nausea, Drug Ineffective, Headache, Diarrhoea. By volume, the top reported reactions are: Fatigue (25,848 reports), Nausea (22,026 reports), Drug Ineffective (20,555 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Levothyroxine Sodium.
Out of 304,316 classified reports, 183,040 (60.1%) were classified as serious and 121,276 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 Levothyroxine Sodium break down by patient sex as follows: Female: 230,799, Male: 54,803, Unknown: 433. 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 Levothyroxine Sodium adverse events are: age 65: 5,296 reports, age 66: 4,883 reports, age 70: 4,865 reports, age 67: 4,863 reports, age 69: 4,790 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 Levothyroxine Sodium adverse event reports is Abbvie Inc.. 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 Levothyroxine Sodium include: Dyspnoea, Pain, Dizziness, Asthenia, Arthralgia. 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 Levothyroxine Sodium 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.
Levothyroxine Sodium has a safety concern score of 65 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. Fatigue and nausea are the most common adverse reactions reported.
Key safety signals identified in Levothyroxine Sodium's adverse event data include: FATIGUE and NAUSEA are the most common reactions.. DEATH and PNEUMONIA are serious adverse events.. DRUG INEFFECTIVENESS and FALL are frequently reported.. HYPERTENSION and HYPOTENSION are noted, indicating potential cardiovascular effects.. DRUG INTERACTIONS are a key safety signal, especially with other thyroid medications.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.
Levotroxine sodium can interact with other thyroid medications and may cause hypertension or hypotension. Patients should be monitored for these conditions and informed of potential drug interactions. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Levothyroxine Sodium.
Monitor for signs of hypothyroidism or hyperthyroidism, especially in older adults. Inform your healthcare provider about all medications and supplements you are taking to avoid potential drug interactions.
Levothyroxine Sodium has 665,570 adverse event reports on file with the FDA. Serious adverse events, such as death and pneumonia, account for 60.1% of total reports. The volume of reports for Levothyroxine Sodium reflects both the drug's usage level and the vigilance of the reporting community.
The FDA continues to monitor Levotroxine sodium for safety. 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.
Explore other medications manufactured by AbbVie Inc. and compare their safety profiles:
The following drugs share commonly reported adverse reactions with LEVOTHYROXINE SODIUM:
Drugs related to LEVOTHYROXINE SODIUM based on therapeutic use, drug class, or shared indications: