7.1 Types of Prescribing Errors
Key Takeaways
- Prescribing errors include abnormal doses, incorrect strength, wrong drug, wrong route, wrong directions, wrong timing, and missing dose or omitted therapy
- Technicians screen profiles, new prescriptions, and CMR/TMR documents for numeric and naming red flags before the pharmacist finalizes clinical judgment
- Look-alike/sound-alike names, decimal-point mistakes, and incomplete sigs are classic sources of wrong-drug and wrong-dose prescribing errors
- Escalate any suspected prescribing error to the pharmacist—never change the prescribed regimen yourself or release a questionable order as “probably fine”
- Document what you observed (drug, strength, sig, source document) so the pharmacist can clarify with the prescriber and update the MAP or PMR
Types of Prescribing Errors
Quick Answer: Prescribing errors are mistakes in what was ordered—abnormal or unsafe doses, incorrect strength, wrong drug, wrong route, wrong or incomplete directions/timing, or a missing dose/omitted therapy. In MTM, technicians screen new prescriptions, refill patterns, PMRs, and CMR notes for these signals and escalate to the pharmacist; they do not independently redesign therapy.
Domain 2 of the PTCB Medication Therapy Management Certificate (Patient Safety and Quality Assurance Strategies) expects you to recognize types of prescribing errors. These errors start with the order itself. They are different from dispensing mistakes (wrong NDC pulled) and from adherence problems (patient skips doses). If the written or electronic order is wrong, every later step can look “correct” while the patient still receives unsafe therapy.
Your role is a systematic screen: compare the order to usual ranges, the patient’s other meds, allergies, and age/weight clues when available. When something looks abnormal, flag and escalate. The pharmacist assesses clinical appropriateness and contacts the prescriber when clarification or a change is needed.
Why Prescribing Errors Matter in MTM Workflows
MTM visits (CMRs and TMRs) and day-to-day profile reviews often surface orders that were never clinically safe—even if they have been filled for months. A patient may have been discharged on an inpatient dose that is too high for outpatient use, or a refill may continue an antibiotic course that should have stopped. Catching these during documentation accuracy reviews and medication therapy reviews protects patients and improves Star Ratings and quality metrics that depend on safe, effective regimens.
Exam cue: when a stem describes an order that “doesn’t look right” before the patient even takes it, think prescribing error, then choose the action that alerts the pharmacist—not silent override, not technician dose adjustment.
Core Prescribing-Error Types (Technician Screen Table)
| Error type | What it looks like | High-yield example | Technician action |
|---|---|---|---|
| Abnormal dose | Quantity/strength × frequency produces an unusually high or low daily amount | Digoxin 0.25 mg BID for a frail older adult (often too aggressive) | Flag total daily dose; escalate |
| Incorrect strength | Right drug name, wrong concentration or tablet strength | Metoprolol succinate 200 mg daily ordered when patient was stable on 50 mg | Flag vs prior dose; escalate |
| Incorrect drug | Wrong molecule or wrong product for the indication | Hydralazine ordered when hydrochlorothiazide was intended (look-alike) | Flag LASA risk; escalate |
| Incorrect route | Route does not match dosage form or indication | Oral vancomycin ordered for systemic MRSA when IV was intended | Flag route/form mismatch; escalate |
| Incorrect directions | Sig incomplete, contradictory, or clinically implausible | “Take as directed” for warfarin with no INR plan on file | Flag vague/unsafe sig; escalate |
| Incorrect timing | Frequency or clock-time conflicts with food, other drugs, or pharmacology | Levothyroxine with breakfast and a calcium tablet at the same time | Flag timing conflict; escalate |
| Missing dose / omitted therapy | Needed strength, frequency, duration, or indicated drug absent | Statin omitted after ACS; antibiotic with no duration | Flag gap or incomplete order; escalate |
Use this table as a mental checklist when you open a new e-prescription, a hospital discharge list, or a draft PMR.
Abnormal Doses and Incorrect Strength
Abnormal dose means the prescribed amount falls outside usual adult or pediatric ranges, or is unsafe for age, renal function, or indication—even if the drug name is correct. Clues include extreme tablet counts per day, pediatric-looking doses in adults (or the reverse), and sudden jumps from a prior stable dose without explanation.
Incorrect strength is a close cousin: the drug is right, but the product strength is wrong (e.g., glipizide 10 mg vs 2.5 mg; insulin U-100 vs U-500). Decimal-point errors (0.5 mg written as 5 mg) and trailing zeros (1.0 mg misread as 10 mg in legacy handwriting workflows) are classic mechanisms. In e-prescribing, wrong selection from a drop-down can produce the same result.
Scenario: A CMR intake shows “methotrexate 2.5 mg tablets — take 10 tablets daily.” Weekly dosing is standard for many rheumatoid arthritis regimens; daily dosing at that quantity is a life-threatening prescribing pattern. Do not “fix” the schedule yourself. Document the sig, stop any release if you control the queue, and escalate immediately to the pharmacist for prescriber clarification.
Incorrect Drug, Route, Directions, and Timing
Incorrect drug includes wrong molecule (clonidine vs clonazepam), wrong salt/product when clinically different (metoprolol tartrate vs succinate dosing schedules), and wrong formulation (extended-release ordered as immediate-release instructions). Look-alike/sound-alike (LASA) pairs and similar proprietary names drive many of these errors.
Incorrect route appears when the ordered route cannot achieve the intended effect (oral vancomycin for bloodstream infection) or when the dosage form does not support the route (crushing and tubing a non-crushable long-acting tablet as if it were an oral solution).
Incorrect directions cover missing frequency, “UD” without a clear patient-facing plan, conflicting lines (“one tablet daily” and “one tablet twice daily” on the same drug), and directions that ignore boxed warnings (e.g., abrupt stop language missing for certain agents when relevant to counseling).
Incorrect timing includes wrong frequency (BID vs daily), wrong relation to meals, and schedules that guarantee interaction (quinolone with polyvalent cations at the same clock time). Timing errors blur into interaction problems; still classify the order defect as a prescribing/timing error when the sig itself creates the conflict.
Missing Dose and Incomplete Orders
A missing dose error can mean the strength or frequency field is blank, the duration is absent for an acute therapy, or a clinically indicated medication is omitted from a discharge or chronic regimen (gap in therapy that began as a prescribing omission). Incomplete pediatric orders that lack weight-based context, or opioid orders without clear quantity/day limits when required by policy, also fit this bucket for screening purposes.
Scenario: Discharge med list includes “apixaban ___ mg BID” with a blank strength after a new atrial fibrillation diagnosis. Filling cannot safely proceed on a blank field. Escalate for pharmacist–prescriber clarification before the patient leaves without anticoagulation or with a guessed dose.
Technician Boundaries (Hard Rule)
| Allowed | Not allowed |
|---|---|
| Screen orders and profiles for the error types above | Change dose, drug, route, or schedule on your own |
| Document exact findings and source (eRx, discharge list, patient report) | Tell the patient “it’s probably a typo—just take half” |
| Escalate to the pharmacist promptly | Override clinical decision support without pharmacist review |
| Support pharmacist clarification workflow (hold, note, follow-up) | Assume chronic refill history proves the order is safe |
Prescribing-error recognition is a patient-safety skill. On the exam and in practice, the correct next step is almost always escalate to the pharmacist with clear documentation—not independent clinical redesign.
Linking Errors to MTM Documents
When you find a prescribing error during PMR, MAP, or CMR preparation, record it so the pharmacist can address it in the Medication Therapy Review and, if needed, communicate with the prescriber. The MAP may later include patient-friendly steps once therapy is corrected. Until then, your job is accurate detection and escalation—not improvising a temporary regimen.
A new e-prescription reads “methotrexate 2.5 mg — take 10 tablets by mouth daily” for rheumatoid arthritis. What is the technician’s best immediate action?
Which situation best illustrates an incorrect-route prescribing error?
During PMR preparation, the strength field for newly prescribed apixaban is blank on a discharge list. What type of prescribing problem is this, and what should the technician do?
A technician notices “Take as directed” as the only sig on a new warfarin prescription with no accompanying patient instructions on file. Which prescribing-error category does this primarily represent?