Ptcb Quiz: Prescription Errors
20 questions · exam conditions
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Prescription ErrorsQuestion 1 of 20

A technician receives a handwritten prescription for "Lamictal 250 mg #30, 1 tab PO daily". The patient's profile indicates a diagnosis of onychomycosis (nail fungus) but no history of seizures or bipolar disorder.

Based on the patient's diagnosis, the technician should suspect an incorrect drug error. Which medication was most likely intended?

Lamisil
Lasix
Lantus
Lipitor
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Ptcb Quiz

Ptcb Quiz: Prescription Errors

Practice Prescription Errors in Ptcb with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Prescription Errors, giving you a quick way to practice the rules, question types, and explanations that matter most for Ptcb.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A technician receives a handwritten prescription for "Lamictal 250 mg #30, 1 tab PO daily". The patient's profile indicates a diagnosis of onychomycosis (nail fungus) but no history of seizures or bipolar disorder.

Based on the patient's diagnosis, the technician should suspect an incorrect drug error. Which medication was most likely intended?

  1. Lamisil (correct answer)
  2. Lasix
  3. Lantus
  4. Lipitor
Explanation: This is a potential look-alike/sound-alike (LASA) error. Lamictal (lamotrigine) is an anticonvulsant, whereas Lamisil (terbinafine) is an antifungal used to treat nail fungus. Given the patient's diagnosis, Lamisil is the intended medication. Lasix is a diuretic, Lantus is insulin, and Lipitor is a statin.

Question 2

A prescription for amoxicillin is presented for "Jane Smith, DOB 05/12/1985". The pharmacy system has two patients named Jane Smith. The profile for the Jane Smith with the matching DOB has a documented, severe penicillin allergy.

This situation presents a high risk for which two types of medication errors?

  1. Incorrect dose and incorrect quantity
  2. Incorrect patient and incorrect drug (correct answer)
  3. Incorrect route and incorrect frequency
  4. Incorrect time and incorrect dosage form
Explanation: There is a risk of selecting the wrong patient (the other Jane Smith). More critically, even if the correct patient is selected, amoxicillin is a penicillin antibiotic. Dispensing it to a patient with a known penicillin allergy would be a severe 'incorrect drug for this patient' error. The technician must alert the pharmacist immediately.

Question 3

A technician is preparing a prescription with the following sig: "Instill 2 gtts AU BID for 7 days."

If the technician incorrectly interprets "AU" and labels the medication for use in the eyes, what type of error has occurred?

  1. Incorrect route (correct answer)
  2. Incorrect dose
  3. Incorrect frequency
  4. Incorrect duration
Explanation: The abbreviation "AU" stands for auris uterque, which means "both ears." Labeling an otic (ear) medication for ophthalmic (eye) use is a critical incorrect route of administration error that could cause significant harm to the patient.

Question 4

A prescription for azithromycin 250 mg tablets reads: "Take 2 tablets by mouth on day 1, then 1 tablet by mouth daily on days 2-5. Dispense #30."

What type of error is present on this prescription?

  1. Incorrect dose
  2. Incorrect route
  3. Incorrect drug
  4. Incorrect quantity (correct answer)
Explanation: The prescribed course of therapy requires 2 tablets on day 1 and 1 tablet for the next 4 days, for a total of 6 tablets. This corresponds to a standard Z-Pak. The quantity of 30 is incorrect for the directions provided and should be clarified with the prescriber.

Question 5

A prescription is written for amoxicillin suspension for a child weighing 20 kg. The prescription calls for a dose of 750 mg twice daily. The recommended pediatric dose range for this indication is 25-45 mg/kg/day.

What type of error should the technician suspect?

  1. Incorrect dose (correct answer)
  2. Incorrect patient
  3. Incorrect route
  4. Incorrect quantity
Explanation: First, calculate the recommended daily dose range. Lower end: 20 kg * 25 mg/kg/day = 500 mg/day. Upper end: 20 kg * 45 mg/kg/day = 900 mg/day. The prescribed daily dose is 750 mg * 2 = 1500 mg/day. This prescribed dose is significantly higher than the recommended maximum, indicating a potential incorrect dose error that requires pharmacist intervention.

Question 6

A pharmacy receives an e-prescription for "Zoloft (levothyroxine) 100 mcg, 1 tab daily".

This prescription contains what type of error?

  1. An incorrect frequency
  2. A mismatched brand and generic name (correct answer)
  3. An incorrect strength
  4. An incorrect route of administration
Explanation: This is an incorrect drug error. Zoloft is the brand name for sertraline, an antidepressant. Levothyroxine (brand name Synthroid, among others) is a thyroid hormone. The brand and generic names on the prescription do not match, requiring immediate clarification with the prescriber.

Question 7

A patient brings in a prescription for "FML Forte ophthalmic suspension, instill 1 drop in right ear QID".

The technician should alert the pharmacist to a potential error regarding the:

  1. Drug strength
  2. Dosing frequency
  3. Route of administration (correct answer)
  4. Patient's name
Explanation: FML Forte (fluorometholone) is an ophthalmic (eye) preparation. The instructions are for otic (ear) use. Prescribing an eye drop for the ear is an incorrect route and requires clarification, as the formulation and delivery device are specific to the eye.

Question 8

An order for Keflex is entered for a patient whose profile has a listed allergy to ceftriaxone.

Alerting the pharmacist to this potential issue would help prevent what type of medication error?

  1. Incorrect drug (correct answer)
  2. Incorrect quantity
  3. Incorrect patient
  4. Incorrect route
Explanation: Keflex (cephalexin) and ceftriaxone are both cephalosporin antibiotics. Patients with an allergy to one cephalosporin may have a cross-sensitivity to others. Dispensing Keflex would be an 'incorrect drug' error for this specific patient due to the potential for an allergic reaction.

Question 9

A prescription reads: "Lisinopril 20 mg. Sig: 1 tab PO BID. Dispense: #30."

What type of error is present on this prescription?

  1. Incorrect drug
  2. Incorrect dose
  3. Incorrect quantity (correct answer)
  4. Incorrect route
Explanation: The instructions (Sig) call for 1 tablet twice a day (BID). For a 30-day supply, the patient would need 1 * 2 * 30 = 60 tablets. The quantity of 30 would only last for 15 days. This is an incorrect quantity because it does not match the days' supply indicated by the directions.

Question 10

A patient drops off a prescription for Ms. Anderson. The technician pulls up the profile for Ann Anderson, DOB 03/15/1960. The patient confirms this is her.

To best prevent an incorrect patient error, what is the next piece of information the technician should ask the patient to verify?

  1. Her preferred pharmacy
  2. Her home address (correct answer)
  3. Her prescribing doctor's name
  4. The name of the medication
Explanation: Using at least two patient identifiers is a critical safety check. After confirming the name and date of birth, verifying a third identifier like the home address or phone number is the best practice to ensure the correct patient record is being used, especially if there are multiple patients with similar names.

Question 11

A prescription is received for "MS Contin 15 mg, 1 tablet every 12 hours, crush and mix with applesauce."

The instruction to crush the tablet is a dangerous error related to the drug's:

  1. Dosage form (correct answer)
  2. Therapeutic class
  3. Expiration date
  4. Schedule class
Explanation: MS Contin is a long-acting, controlled-release formulation of morphine sulfate. Crushing the tablet destroys this mechanism, causing the entire 12-hour dose to be released at once (dose dumping). This can lead to a fatal overdose. This is an incorrect administration error related to the drug's specific dosage form.

Question 12

A new e-prescription arrives for "Digoxin 2.5 mg. Take one tablet daily."

This prescription most likely contains what kind of error?

  1. Incorrect drug
  2. Incorrect patient
  3. Incorrect dose (correct answer)
  4. Incorrect route
Explanation: Digoxin has a very narrow therapeutic index, and doses are typically in micrograms (mcg), not milligrams (mg). Common strengths are 125 mcg (0.125 mg) or 250 mcg (0.25 mg). A dose of 2.5 mg is 10 times the usual maximum dose and would be lethal. This is a critical incorrect dose error, likely caused by a misplaced decimal.

Question 13

A prescription reads "Debrox solution, apply 5 drops to right eye BID".

The technician should recognize this as a potentially harmful error in the:

  1. Drug strength
  2. Route of administration (correct answer)
  3. Dosing frequency
  4. Quantity dispensed
Explanation: Debrox (carbamide peroxide) is an otic solution used to remove earwax. It is not formulated for ophthalmic (eye) use and would cause severe irritation and chemical injury if instilled in the eye. This is a critical incorrect route of administration error.

Question 14

A prescriber writes a new prescription for Norco 5/325, "1-2 tabs Q4-6H PRN pain, #180 (one hundred eighty)" for a patient after a tooth extraction. State law limits the first fill of an opioid for acute pain to a 5-day supply.

The technician should identify an issue with the prescription's:

  1. Dosing interval
  2. Drug strength
  3. Route of administration
  4. Quantity (correct answer)
Explanation: A 5-day supply at the maximum dose would be (2 tabs * 6 times/day) * 5 days = 60 tablets. The prescribed quantity of 180 tablets far exceeds the legal limit for an initial prescription for acute pain in many states. This is an incorrect quantity error based on legal restrictions, which requires pharmacist intervention.

Question 15

A hospital order is written as "Regular Insulin 10 U sliding scale AC".

According to ISMP, the abbreviation "U" for units is on the "Do Not Use" list because it is frequently misread, leading to what type of error?

  1. Incorrect drug
  2. Incorrect patient
  3. Incorrect route
  4. Incorrect dose (correct answer)
Explanation: The abbreviation 'U' for units is easily mistaken for a zero ('0') or the number four ('4'), leading to a 10-fold overdose or a significant underdose, respectively. For safety, the word "units" must always be written out in full. Using 'U' is an error-prone practice that can cause a serious incorrect dose error.

Question 16

A technician receives a prescription for "Celebrex 100 mg daily for depression."

This prescription likely contains an incorrect drug error. Based on the indication, which look-alike/sound-alike drug was most likely intended?

  1. Celexa (correct answer)
  2. Cerebyx
  3. Cefzil
  4. Zyprexa
Explanation: Celebrex (celecoxib) is a nonsteroidal anti-inflammatory drug (NSAID) for pain and inflammation. Celexa (citalopram) is a selective serotonin reuptake inhibitor (SSRI) used to treat depression. This is a classic LASA pair, and the indication of depression points directly to Celexa as the intended medication.

Question 17

An electronic prescription is received for "Warfarin 5.0 mg, Take 1 tablet by mouth daily".

According to best practices from the Institute for Safe Medication Practices (ISMP), what type of error is present in the way this dose is written?

  1. Use of a leading zero
  2. Use of a trailing zero (correct answer)
  3. Unapproved abbreviation
  4. Incorrect route specified
Explanation: The use of a trailing zero (e.g., 5.0 mg) is an error-prone practice and should be avoided. The decimal point can be missed, leading to the dose being misread as 50 mg, a 10-fold overdose. The correct way to write this dose is "5 mg". A leading zero (e.g., 0.5 mg) is a safety practice used to prevent a dose from being misread.

Question 18

A prescription for methotrexate 2.5 mg tablets reads: "Take 4 tablets by mouth once weekly."

A common and potentially fatal error associated with this high-alert medication involves misinterpreting the frequency, resulting in an incorrect:

  1. Dose (correct answer)
  2. Route
  3. Patient
  4. Drug
Explanation: Methotrexate is often dosed weekly for conditions like rheumatoid arthritis. A frequent error is for the instructions to be entered or read as "daily" instead of "weekly." This leads to a massive overdose and severe toxicity. This is a critical incorrect dose error related to frequency.

Question 19

A patient presents a new prescription for Januvia. When the technician asks what the medication is for, the patient replies, "It's a new antibiotic for my sinus infection."

The technician should recognize this as a red flag for a potential:

  1. Incorrect drug error (correct answer)
  2. Incorrect dose error
  3. Incorrect patient error
  4. Incorrect quantity error
Explanation: Januvia (sitagliptin) is a medication used to treat Type 2 diabetes, not a sinus infection. The mismatch between the drug's actual indication and the patient's understanding of its purpose is a major red flag for an incorrect drug error and requires clarification with the prescriber.

Question 20

A prescription for Cipro (ciprofloxacin) is written for an 8-year-old child for a routine urinary tract infection.

The technician should flag this prescription for pharmacist review because Cipro is generally not recommended in children, representing a potential:

  1. Incorrect drug for the patient's age (correct answer)
  2. Incorrect quantity for a pediatric patient
  3. Incorrect route of administration
  4. Therapeutic duplication
Explanation: Fluoroquinolones like ciprofloxacin are generally avoided in pediatric patients due to the risk of cartilage and tendon damage. While there are specific exceptions, its use for a routine infection in a child is a red flag, representing a potential 'incorrect drug' error for this patient population.