Pharmacy Errors – Avoid Prescription Dispensing Mistakes

Reading time: 8 – 14 minutes

Recently, an undercover pharmacy investigation conducted by 20/20 and reported on by Chief Investigative Correspondent Brian Ross evaluated prescription dispensing at some of the best known U.S. chain drug stores.

The results are surprising and the suggestions at the end of this article really could save your life or that of someone you love.

Pharmacy errors and prescription drugs

Prescription error

With the exception of a few states, pharmacies in the U.S. are not required to report errors that involve serious injury or death. There are no federal requirements, so no one knows just how many errors occur [1]. The industry says that errors represent only a small percentage of the billions of prescriptions filled every year. In 2003, a study of dispensing accuracy rates in 50 pharmacies located in 6 cities across the U.S. found an overall dispensing accuracy rate of 98.3% (77 errors among 4,481 prescriptions) [2]. Of the 77 errors identified, 5 (6.5%) were judged to be clinically important. The authors of the study concluded that pharmacy dispensing errors are a problem on a national level, at a rate of about 4 errors per day in a pharmacy filling 250 prescriptions daily. Each year, an estimated 51.5 million errors occur during the filling of 3 billion prescriptions.

Similarly, a study of pharmacy dispensing errors in the UK identified on average, for every 10,000 items dispensed, 22 near misses and 4 dispensing errors [3].

To investigate pharmacy errors, a team of 20/20 producers conducted an undercover four month investigation. The ABC field test was designed and supervised by Dr. Ken Barker, Director of the Center for Pharmacy Operations Design and Dr. Betsy Flynn, Associate Research Professor in the Department of Pharmacy Care Systems at Auburn University’s School of Pharmacy as part of their ongoing research on how to help pharmacists overcome errors.

In three major U.S. metropolitan areas, 100 big-chain drugstores were tested for pharmacy errors using first-time prescriptions, which under most state laws require pharmacists to counsel patients about potential dangerous interactions or problems unless patients decline. The ABC-Auburn study evaluated the following:

  1. Did the pharmacy dispense what was prescribed?
  2. Was a pharmacist present to counsel customers?
  3. Did the pharmacy identify a potentially dangerous drug interaction?

Producers were instructed to select a large bottle of aspirin and take it to the counter at the same time they picked up a prescription for the blood thinner coumadin. The intention was to cause pharmacy personnel to tell patients there was a serious drug interaction between coumadin and aspirin.


In just over 30% of cases (8 out of 25), pharmacists identified the potentially dangerous combination of drugs and warned patients. The other 70% were never told about the deadly drug interaction between aspirin and coumadin. Counseling was only offered in 27 of 100 cases. In 73% of cases, no counseling was given without prompting by producers.

Lack of patient counseling in community pharmacies has been shown to be a problem in the past. In a recent study in eight states, 306 community pharmacies were evaluated for pharmacist consultation on new prescriptions [4]. Counseling varied significantly according to intensity of state regulation, pharmacy busyness and age of responsible pharmacist.

In addition, 20/20 discovered something that may come as a surprise to many drug store customers, that they were being misled into signing away the right to counseling. In what may be a serious deception on the part of most pharmacies, they never explained that patient signatures to “show that the medication was picked up” were also being used to waive the legal right to counseling with a pharmacist [5].

That’s right, when you sign that you received your prescription, what you’re really doing is signing away your legal right to pharmacist counsel.

I have mixed feelings regarding this result. The 20/20 report doesn’t indicate whether patients were asked if they had any questions, only that counseling was offered in 27 of 100 cases. In my experience, whenever I’ve picked up medication from a pharmacy, I’m asked if I have any questions for the pharmacist about the medication or it’s effects. Thus, my signature would not waive my right to counseling if I was asked if I had any questions for the pharmacist and declined.

Of the 100 prescriptions, there were no cases of the wrong medication being dispensed. The overall error rate was 22% and included too many or too few pills, faulty and missing instructions on the labeling, and failure to put a childproof cap on one prescription.

Nonetheless, the results are better than a recent study evaluating medication errors in health care facilities. In 2002, a study to identify the prevalence of medication errors (meaning doses administered differently than ordered) was conducted on a stratified random sample of 36 institutions in Georgia and Colorado, including hospitals accredited by the Joint Commission on Accreditation of Healthcare Organizations, non-accredited hospitals and skilled nursing facilities [6].

In the 36 institutions, 19% of the doses (605/3216) were in error. The most frequent errors were:

  • Wrong time of administration (43%)
  • Omission (30%)
  • Wrong dose (17%)
  • Unauthorized drug (4%)

Seven percent of the errors were judged potential adverse drug events. The authors found that medication errors occurred in nearly 1 of every 5 doses in the typical hospital and skilled nursing facility. The percentage of errors rated potentially harmful was 7%, or more than 40 per day in a typical 300-patient facility.

Another study found similar results during a seven-month period at an academic tertiary care hospital, with the hospital pharmacist failing to detect 21% of medication dispensing errors [5].

The drug stores involved in the 20/20 investigation have responded to the study stating that that pharmacy errors are unacceptable.

It’s About the Bottom line

According to Bill Kennedy, former senior pharmacist for Walgreens, overworked pharmacists are pushed to fill prescriptions at a very high pace [8].

Kennedy’s job was threatened because he would not work as fast as Walgreens wanted [1].

Walgreens has always had a problem with me that I don’t “keep up” getting the prescriptions out in a timely manner.
I’m slow […] because I take the time to do what I think is the way to do the job properly.

Indeed, pharmacies are so busy they rely heavily on pharmacy technicians, often high school students, that are allowed to fill prescriptions.

Did you get that? Some pharmacies allow pharmacy technicians, often high school students, to fill prescriptions.

Comments regarding the study

A number of comments at the 20/20 site in response to the study are worth noting.

Demanding and distracting work conditions, understaffing and illegible prescriber hand writing are frequently cited as daily issues pharmacists must face. Indeed, one reader asked why there isn’t a law requiring that prescriptions be typewritten rather than handwritten.

Several readers indicated that numerous prescription mistakes made by doctors, physician’s assistants or nurses are identified and corrected by pharmacists, suggesting that pharmacists have helped more than harmed patients.

The issue of wait time and patient demand for immediate service was repeatedly discussed.

A registered practicing retail pharmacist writes:

… I think that everyone needs to understand what it is exactly that the pharmacist does behind the counter in between being griped at by angry patients concerning insurance claims or longer than 15 minute wait times or just someone coming up that wants nothing from the pharmacy other than to be rung up. I think that the general public and evidently 20/20 does not understand that it is the pharmacist’s ultimate responsibility to make sure that your prescription is accurate (this includes multiple aspects of checking – right patient, right drug, right drug strength, right quantity, right directions, right refills, right doctor just to name a few). AND NOT ONLY IS IT ACCURATE, we check to make sure that there are no drug interactions or allergies. We also check that the dose is reasonable and will not harm the patient. This is our ultimate responsibility – our reason for being. Not to count by 5’s or explain why insurance/drugs cost so much. I think that it’s quite funny that 20/20 is trying to rile people up because a pharmacist is not counting your prescription. That is not our responsibility, simply put. However, it is our responsibility when something goes out wrong. Technicians are to be prudent and fill responsibility, but everything they do is to be double checked by the pharmacist.

Final thoughts

Both the 20/20 study and previously published research studies [2,3,6,7] show that pharmacy errors do exist. Even with the introduction of technology and process improvements, errors may still occur. Take an active part in managing your health. When you get a prescription from your doctor, ask questions:

  • What is the name of the medication?
  • What affects does the medication have?
  • What is the proper dosage?
  • What side effects should you watch for?
  • Are there any drug interactions that you should be aware of?

Ask these same questions with the pharmacist when you pick up the medication. Make sure you pop the lid and check the medication before you leave the pharmacy counter – this provides both the patient and the pharmacist an opportunity to do a final visual check together and opens up dialogue. Personally, I even make it a point to look up prescription medications online when I get home.

Take the time and educate yourself so that you can protect you and the ones you love.


  1. ABC News Webcast – Brian Ross Investigates Prescription Errors, March 30, 2007.
  2. Flynn et al. National observational study of prescription dispensing accuracy and safety in 50 pharmacies. J Am Pharm Assoc (Wash). 2003 Mar-Apr;43(2):191-200.
    View abstract
  3. Ashcroft et al. Prospective study of the incidence, nature and causes of dispensing errors in community pharmacies. Pharmacoepidemiol Drug Saf. 2005 May;14(5):327-32.
    View abstract
  4. Svarstad et al. Patient counseling provided in community pharmacies: effects of state regulation, pharmacist age, and busyness. J Am Pharm Assoc (Wash DC). 2004 Jan-Feb;44(1):22-9.
    View abstract
  5. ABC News Webcast – What Your Pharmacist Doesn’t Tell You, March 30, 2007.
  6. Barker et al. Medication errors observed in 36 health care facilities. Arch Intern Med. 2002 Sep 9;162(16):1897-903.
    View abstract
  7. Cina et al. How many hospital pharmacy medication dispensing errors go undetected? Jt Comm J Qual Patient Saf. 2006 Feb;32(2):73-80.
    View abstract
  8. 20/20 In Touch Webcast. Tragic Mistakes.
About the Author

Walter Jessen, Ph.D. is a Data Scientist, Digital Biologist, and Knowledge Engineer. His primary focus is to build and support expert systems, including AI (artificial intelligence) and user-generated platforms, and to identify and develop methods to capture, organize, integrate, and make accessible company knowledge. His research interests include disease biology modeling and biomarker identification. He is also a Principal at Highlight Health Media, which publishes Highlight HEALTH, and lead writer at Highlight HEALTH.