Medication Errors in the U.S.: New Analysis Reveals Who’s Most at Risk

Medication mistakes remain one of the most stubborn and preventable dangers in American healthcare, cutting across hospitals, clinics, pharmacies, nursing homes, and even private homes. Whether they stem from surgery, diagnostic issues, misread lab results, faulty medical devices, or the wrong drug being given, these errors cause serious — and sometimes fatal — harm every year.

An estimated 1.5 million Americans are affected annually by a medication error, and 91% of those mistakes occur at the prescribing stage. The outcomes range from adverse reactions and emergency hospitalizations to life-threatening events.

A new analysis from Siegfried Jensen sets out which drugs most often feature in these errors, which patients are at greatest risk, the most common types of mistakes, and the states with the most alarming pharmacy disciplinary records.

Which Medications Are Most Often Involved in Errors?

Each year, between 7,000 and 9,000 Americans die as a direct result of medication or prescription errors, and around 500,000 people require hospitalization due to adverse effects. The danger is especially acute among adults aged 65 and over, one of the heaviest medication-using groups in the country.

Certain drug classes appear again and again in national error data, either because they are prescribed so frequently or because the consequences of mismanagement are so severe:

• Antibiotics are involved in 20% of all medication errors, reflecting their widespread use and the need for tightly controlled dosing and timing.

• Antipsychotic medications appear in 19% of errors, highlighting the importance of careful oversight in mental-health care.

• Central nervous system (CNS) drugs — often used for anxiety, sleep disorders, and seizures — account for 16% of reported mistakes.

• Cardiovascular medications, critical for conditions like high blood pressure and heart disease, make up 15% of errors.

• Opioids, although responsible for a smaller share (7%), are particularly concerning due to the risk of misuse, addiction, and overdose.

Taken together, these figures underline how crucial it is to tighten prescribing, dispensing, and administration practices, particularly for high-risk medications that are staples in hospitals, long-term care facilities, and outpatient settings.

Who Is Most at Risk From Prescription Errors?

Medication errors do not impact all patients equally. Age, health status, and treatment complexity all influence the level of risk.

• Older adults face some of the highest stakes. Nearly 90% of Americans aged 65+ are on at least one prescription drug, and almost 40% take five or more — a situation known as polypharmacy.

• Patients on five or more medications are 30% more likely to experience a medication error, and that risk climbs to 38% among adults 75 and older.

People living with mental health disorders also face elevated risk. Antipsychotic medications — which require precise dosing and close monitoring — are implicated in nearly one in five medication errors. At the same time, 26% to 49% of individuals with severe mental illness unintentionally misuse their medications because of confusion, side effects, or lack of oversight.

Children and adults with chronic diseases such as diabetes, epilepsy, and heart disease depend on long-term, finely tuned medication regimens. Even minor errors in dose or timing can trigger acute medical crises, making them especially vulnerable to mistakes.

The Most Common Medication Errors in Healthcare

Medication errors can occur at every step of the treatment process — from the initial prescription to administration at the bedside or at home.

In hospitals, the most frequently reported error is giving a medication at the wrong time, responsible for 33.6% of incidents. Poor timing can make drugs less effective or increase the risk of side effects, particularly for medications that require strict schedules, like antibiotics or blood thinners.

Other common errors include:

• Wrong dosage: 24.1% of errors

• Wrong drug: 17.2% of cases

These mistakes often stem from miscommunication, unclear orders, mislabeled medications, or drugs with similar names and packaging.

In pharmacies, errors typically involve:

• Dispensing the wrong medication

• Dispensing the wrong dosage strength

• Providing the wrong quantity

Look-alike, sound-alike (LASA) drug errors remain a major source of harm and may account for up to 25% of all reported medication mistakes.

In the home setting, particularly for children, caregivers can struggle with reading instructions, measuring doses accurately, and keeping track of timing. Errors in these situations range from 2% to 33%, depending on how complex the regimen is and how clear the directions are.

Across all settings, the pattern is clear: children, older adults, and people taking multiple prescriptions face the greatest risk.

Pharmacy Discipline: States With the Most Incidents

A 2024 review of pharmacist disciplinary records reveals that a relatively small group of states account for a disproportionate share of adverse reports.

• Texas recorded the highest number of pharmacist disciplinary actions at 127, followed by Michigan (114) and Ohio (106).

• California (86) and Nevada (85) also reported high numbers, pointing to regulatory and workload challenges in large or fast-growing healthcare markets.

• Florida (72), New York (61), Kansas (56), Kentucky (41), and Massachusetts (39) rounded out the top ten.

These figures suggest deeper problems in prescription monitoring and oversight, particularly in states with large senior populations, high medication volumes, or chronic staffing pressures.

Why Medication Errors Occur

Most medication errors are not random; they result from breakdowns in systems, communication, or staffing.

Key contributing factors include:

• Illegible or handwritten prescriptions, which remain a major source of misinterpretation.

• Incomplete patient information, such as missing allergy histories, lab results, or records of other medications.

• Logistical failures, including prescriptions that never reach the pharmacy or drug samples that are handed out but not documented.

Staffing shortages are a major concern. A nationwide survey found that 80% of pharmacists believe inadequate staffing directly contributed to a medication error in the previous year. When pharmacies, hospitals, or clinics are stretched thin, essential safety checks can be rushed or skipped altogether.

The Human and Financial Toll

Every year, medication errors:

• Kill between 7,000 and 9,000 people in the U.S.

• Harm more than 1.5 million others

• Send around 500,000 patients to the hospital due to adverse effects

The consequences can include kidney failure, seizures, internal bleeding, respiratory depression, stroke, and anaphylaxis, among other serious complications.

Older adults and patients on multiple prescriptions are at risk of falls, cognitive decline, and drug toxicity, while people with mental health conditions may experience worsening symptoms or severe side effects if their medications are prescribed or administered incorrectly.

Financially, the burden is enormous:

• Medication-related harm costs the U.S. healthcare system more than $20 billion each year.

• When legal claims, long-term care, and lost productivity are included, the total cost climbs to around $77 billion annually.

• Injectable medication errors alone add an estimated $2.7–$5.1 billion to national healthcare expenses.

These numbers show why medication errors remain one of the most critical — and preventable — patient-safety issues in the country.

Moving Forward: How to Reduce Medication Errors

Cutting medication errors will require systemic change across the entire healthcare chain, not just one-off fixes.

That includes:

• Stronger, safer prescription technologies

• Clearer labeling and packaging

• Better communication systems between prescribers, pharmacists, and patients

• More staffing support to ensure safety checks aren’t skipped

• Expanded patient education so people understand their medications and how to take them correctly

With thousands of preventable deaths and millions of injuries every year, improving medication safety isn’t optional — it’s essential. The data from this analysis makes clear that with better information, tighter oversight, and stronger support for healthcare workers, the U.S. can significantly reduce the human and financial toll of medication errors.