The Food and Drug Administration (FDA) defines a medication error as a “preventable event that may cause or lead to inappropriate medication use or patient harm.” Medication errors can happen because of consumers, healthcare professionals, pharmacists, or other people involved in the medication-use system. Let’s take a look at some medication error statistics to better understand how frequently they happen, how they affect people, and how to prevent them.

What are medication errors?

A medication error happens in the medication-use system and can cause harm to the person taking the medication. Errors can happen when a medication is prescribed improperly, is prepared or dispensed improperly, when drug information is entered into a computer system incorrectly, or when a patient takes a medication incorrectly. Medication errors can involve prescription drugs, over-the-counter medications, vitamins, and even supplements.

There are nine types of medication errors:

Prescribing errors
Failure to prescribe, administer, or dispense a medication
Someone receiving a medication too late or too early
A patient receiving a drug not authorized for them
Improper use of a medication
Wrong dose prescription/preparation
Administration errors
Failure to take into account a patient’s medical conditions or potential drug interactions
Not following proper dispensing/prescribing rules for a medication

It’s important to note that patients and caregivers are also at a high risk for making medication errors. Additionally, one study published in the Journal of the American Geriatrics Society in 2007 outlined six categories of patient medication errors:

Medication filling and refilling errors
Medication administration errors
Failure to perform some parts of the medication regimen
Failure to follow clinical advice
Failure to report information to providers
Failure to adhere to follow-up

How common are medication errors?

The FDA receives more than 100,000 reports every year that are associated with medication errors (FDA, 2019).
Forty-one percent of Americans report having been involved with a medical error either personally or secondhand (Institute for Healthcare Improvement/NORC at the University of Chicago, 2017).
More than 7 million patients in the U.S. are impacted by medication errors every year (Journal of Community Hospital Internal Medicine Perspectives, 2016).
Ten percent of hospital patients will be subject to a medication error (NCBI, 2019).

Medication errors statistics by setting

During medication administration, there is about an 8%-25% median medication error rate (Patient Safety Network, 2018).
Medication errors in the home are estimated to occur at rates between 2%-33% (Patient Safety Network, 2018).
Improper dispensing of medications results in medication error rates between 0.014%-55% (BMJ Open Quality, 2018).
About 1.5% of all prescriptions in the community setting have a dispensing error (BMJ Open Quality, 2018).
One in 5 Americans has experienced a medical error while receiving health care (Institute for Healthcare Improvement/NORC at the University of Chicago, 2017).
Almost 1 in 5 medication doses given during hospital stays are given in error (DataRay, 2002).
About 530,00 injuries happen every year in outpatient clinics because of medical errors (HG.org).
Older patients are more likely to be affected by a medical error during medical care because they tend to take more medications than younger adults (Paul & Perkins, 2021).

Patient medication errors statistics

1 in 5 adverse drug events caused by error were related to patient use of medications in the home (The Journal of the American Medical Association, 2003).
Dosage errors are the most common type of medication administration errors. 7.8% of carers reported giving an insufficient dose, 6.6% reported giving an overdose, and 5.4% reported giving the wrong medication (PLOS One, 2016).
More than half (51%) of parents reported giving incorrect acetaminophen (Tylenol) doses (Pediatric Emergency Care, 2000).
Only 67% of parents were able to accurately repeat back medication use instructions (Pediatrics, 1998).
Only 37% of parents who received verbal instructions measured the correct dose; 83% measured the correct dose with verbal instructions and a marked syringe; 100% measured the correct dose with verbal instructions, a marked syringe, and a dose demonstration (Pediatrics, 1997).

Medication errors statistics by drug type

Intravenous medication administration error has a median medication error rate of 48%-53% (Patient Safety Network, 2018).
As many as 30% of the medication errors that are reported to the U.S. Poison Control Centers involve pediatric patients (U.S. Pharmacist, 2019).
In a study of 14,983 pharmacist interventions, 41.2% of medication errors involved cardiovascular medications (Archives of Internal Medicine, 2003).
Drugs that affect the nervous system, drugs that affect the respiratory system, anticoagulants, and antibiotics are most frequently involved in medication errors according to a study of 44,344 calls concerning pharmaceuticals (Upsala Journal of Medical Sciences, 2012).
Antidiabetic agents (e.g., insulin), oral anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin), and opioid pain medications account for more than 50% of emergency department visits for adverse drug events (ADEs) in Medicare patients (Patient Safety Network, 2019).
As many as 18 million people aged 12 or older may misuse prescription psychotherapeutic drugs every year (NSDUH Data Review, 2015).
Two million Americans misused prescription pain relievers in 2017 (National Institute on Drug Abuse, 2017).

Counterfeit medication statistics

As many as 1% of medicines available in the developed world are counterfeit (World Health Organization, 2011).
Ten percent of medicines globally are counterfeit (WHO, 2006).
About 50% of medicines available over the internet are counterfeit (WHO, 2010).
About 80% of Viagra bought online is fake (Viagra, 2021).
In certain countries, 70% of all drugs in the supply chain are fake pharmaceuticals (National Crime Prevention Council, 2021).
Global sales of counterfeit drugs total more than $75 billion every year (National Crime Prevention Council, 2021).

Consequences of medication errors

Medication errors can have a profound effect on someone’s overall health and quality of life. Receiving and taking the wrong medication, or improperly taking the right medication can lead to serious side effects, hospitalization, and even fatalities. Adverse drug reactions may manifest as skin rashes or skin disfigurements, and some people can even develop new health problems. In the United States, 7,000 to 9,000 people die each year due to medication errors.

If a healthcare professional is at fault for the medication error that causes a patient harm, they may be subject to certain consequences. They may lose their license or their job if the mistake is big enough, but in many cases, it may be difficult to determine what or who caused a medication error as there are many steps involved in getting medication to a patient.

Every year, 7,000-9,000 Americans die as a result of a medication error (NCBI, 2021).
Medication errors are the eighth leading cause of death in the U.S. (DataRay, 1999).
Medication errors cause at least one death every day in the U.S. (WHO, 2017).
Medication errors injure more than 1.3 million people every year in the U.S. (WHO, 2017).
Thirty percent of injuries due to prescription drugs in hospital settings happen because of medication errors (Drug Safety, 1996).

The cost of medication errors

The U.S. spends more than $40 billion each year on patients who have been affected by medication errors (NCBI, 2021).
Preventable medication errors cost the U.S. more than $21 billion every year across all care settings (Journal of Community Hospital Internal Medicine Perspectives, 2016).
The global cost of medication errors is almost 1% of the total global health expenditure (WHO, 2017).

Causes of medication errors

There are many causes of medication errors, including physical, psychological, and environmental causes. “Physical causes might be clerical, misreading, mistyping, or miscalculating a dosage,” says Matthew Young, MD, a physician and attorney who specializes in medical malpractice actions. “Psychological causes could be fatigue, cognitive lapse, or forgetting a patient’s allergies. Environmental causes could be grabbing the wrong medication for the wrong patient, getting the wrong med from the pharmacy, or the pharmacy dispensing the wrong med/preparing the dosage incorrectly.”

According to Dr. Young, proper administration of medication depends on:

Correct route of administration: Intravenous, intramuscular, by mouth, etc.
- Example: Antibiotics may not adequately treat an infection if given orally versus IV.
Correct dosage: Amount, concentration, etc.
- Example: Miscalculating a weight-based medication results in under-dosing of a drug.
Duration: Days, weeks, etc.
- Example: A drug that should be given for six months is only given for five months.
Frequency: Every 12 hours, once a day, etc.
- Example: Certain drugs need to be given less frequently but in higher concentrations to reach peak efficacy.
Selection: Picking the right medication.
- Example: The wrong diagnosis will automatically trigger a medication error.
Avoiding adverse effects and drug-drug interactions: What are the patient’s known drug allergies? What other drugs has the patient been prescribed and when did they last get it? Contraindications?
Discontinuation or modification: Knowing when to start and stop a drug or how to adjust the dose aka titrate the dosage.
- Example: Anti-coagulants, thyroid medication, etc.

If an error happens in any of these categories, then a medication error will have occurred. Other factors may lead to a medication being taken improperly and result in adverse outcomes even if it is prescribed and dispensed correctly. Some examples include health literacy as well as patient-provider communication, misinformation, and disinformation.

How to prevent medication errors

Even though medication errors are common, it’s possible to prevent them with the right quality improvement programs. Many medication errors happen because of human error, and technology has been able to help stop some of this from happening. Electronic medical records can help pick up on potential drug-drug interactions when a patient is prescribed medication and can help keep track of and calculate dosages. Automated dispensing cabinets are also sometimes used for high-risk medications in healthcare facilities.

On a broader scale, certain organizations and institutions are working to prevent medication errors:

The Joint Commission has declared medication safety as a National Patient Safety Goal for ambulatory clinics and hospitals.
The National Coordinating Council for Medication Error Reporting and Prevention issues a set of recommendations that organizations can follow in order to help reduce the incidence of medication errors and preventable adverse drug events.
The Institute for Safe Medication Practices is a 501c (3) non-profit organization that’s devoted entirely to preventing medication errors, and they do investigations into reported medication errors, ongoing advocacy with manufacturers, medication safety self-assessments for healthcare organizations, and much more.

Medication errors questions and answers

How many medication errors occur each year?

The FDA receives more than 100,000 reports of medication errors every year in the United States. There are about 400,000 drug-related injuries that happen in hospitals every year because of medication errors.

What are the main causes of medication errors?

The main causes of medication errors are:

Clinicians prescribing medications improperly
Medications being prepared or dispensed improperly
Information about a medication being entered into a computer system improperly
Patients taking a medication improperly

What are examples of medication errors?

Examples of medication errors include:

The wrong medication being given to someone
Not enough or too much of a medication being given to someone
Improper route of administration
Improper use of a medication by the consumer
Incorrectly making or storing prescription medications
A doctor or a pharmacist failing to administer a medication
Medications not arriving in the mail on time in order for someone to take them properly
Mixing up medications that look-alike
Drug names that sound very similar being switched up
Unclear labeling of a medication

Which classes of medications are typically connected to medication errors?

Intravenous antibiotics are the drugs most commonly involved in medication errors in hospitals, according to a 2009 study. Cardiovascular medications and gastrointestinal agents are also highly associated with medical errors in hospitals.

What are the consequences of medication errors?

Medication errors have many consequences that can affect patients, physicians, nurses, or anyone else involved in the medication-use system. Patients may experience side effects from adverse drug events like skin rashes or the emergence of new medical conditions if they’re given the wrong medication or too little or too much of a medication. Medication errors also cause many deaths around the world.

Physicians that make medication errors may face loss of patient trust, criminal charges, medical board termination, and even a loss of their job. Pharmacists, nurses, and other healthcare providers who make medication errors may also face legal charges or termination from their job.

What is the most counterfeited drug?

Many people in the medical industry believe that Viagra is the most counterfeited drug in the world. The company that makes Viagra, Pfizer, conducted an investigation in 2011 on the ingredients contained in counterfeit Viagra. Pfizer Global Security searched online for “Viagra” using two popular search engines and then ordered pills from the top 22 sites. They found that some pills had too much of the active ingredient or not enough of it, and they discovered ingredients like blue printer ink, amphetamines, metronidazole, and drywall ingredients in the pills.

Medication errors resources

The alarming reality of medication error, Journal of Community Hospital Internal Medicine Perspectives
Global effort to halve medication-related errors in five years, World Health Organization (WHO)
Medication errors. How common are they and what can be done to prevent them?, Drug Safety
Medication administration errors, Patient Safety Network
Systematic review and meta-analysis of community pharmacy error rates, BMJ Open Quality
Americans’ experiences with medication errors and views on patient safety, Institute for Healthcare Improvement/NORC at the University of Chicago
Medication error statistics, DataRay
Prescription drug use and misuse in the United States, SAMHSA
Misuse of prescription drugs research report, National Institute on Drug Abuse
Minimizing medication errors in pediatric patients, U.S. Pharmacist
Growing threat from counterfeit medicines, WHO
Counterfeit medicines: An update on estimates, WHO
Fake drugs are bad medicine, National Crime Prevention Council
Medication errors in hospitalized cardiovascular patients, Archives of Internal Medicine
Medication errors in the children and elderly, Upsala Journal of Medical Sciences
Wrong medication errors, Paul & Perkins
The most common forms of medical errors, HG.org