What does LASA stand for in pharmacy?
Look-Alike / Sound-Alike — drug name pairs similar enough in spelling or sound to cause dispensing errors, like hydroxyzine and hydralazine.
Patient Safety
Look-Alike / Sound-Alike (LASA) Drugs: The Pairs the PTCE Tests
By the RxReflex Content Team
LASA (look-alike/sound-alike) drugs are name pairs so similar they cause real dispensing errors — like hydrOXYzine (an antihistamine) vs hydrALAZINE (a blood-pressure drug). The PTCE tests them inside Patient Safety (23.75% of the 2026 exam), and Tall Man lettering — capitalizing the differing letters — is the safety tool to know.
What are LASA drugs, and why does the exam care?
Two drugs qualify as LASA when their names look or sound close enough that a busy tech can grab the wrong one — on a shelf, on a screen, or over the phone. That's not a trivia category: name confusion is one of the most common real-world dispensing errors, which is why the Patient Safety domain keeps returning to it. The exam typically shows you a pair and asks which drug matches a use, or which safety practice prevents the mix-up.
The classic LASA pairs to know
| Pair (Tall Man) | Drug #1 is… | Drug #2 is… |
|---|---|---|
| hydrOXYzine / hydrALAZINE | Antihistamine — itching & anxiety (hydroxyzine) | Vasodilator — blood pressure (hydralazine) |
| cloNIDine / clonazePAM | Alpha-2 agonist — blood pressure (clonidine) | Benzodiazepine, C-IV — seizures/anxiety (clonazepam) |
| buPROPion / busPIRone | Atypical antidepressant / quit-smoking (bupropion) | Anti-anxiety, NOT a benzo (buspirone) |
| predniSONE / predniSOLONE | Oral corticosteroid — needs liver conversion (prednisone) | The already-active steroid, common in kids (prednisolone) |
| traMADol / traZODone | Opioid pain reliever, C-IV (tramadol) | Antidepressant used for sleep (trazodone) |
| glipiZIDE / glyBURIDE | Sulfonylurea — diabetes (glipizide) | Sulfonylurea — diabetes (older, longer-acting) |
| LaMICtal / LamISIL | Lamotrigine — seizures/bipolar | Terbinafine — antifungal |
| CeleXA / CeleBREX | Citalopram — SSRI antidepressant | Celecoxib — COX-2 NSAID (celecoxib) |
| ZyPREXa / ZyrTEC | Olanzapine — antipsychotic | Cetirizine — allergy antihistamine (cetirizine) |
| hydroCODONE / oxyCODONE | C-II opioid (in Norco/Vicodin combos) | C-II opioid, different potency (oxycodone) |
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Exam tip
Notice the pattern in what makes these dangerous: the two drugs usually treat completely different conditions. Swapping an antihistamine for a blood-pressure drug isn't a small error — that's exactly why the exam keeps testing these.
What is Tall Man lettering?
Tall Man lettering capitalizes the letters that differ between two confusable names — hydrOXYzine vs hydrALAzine — so the eye catches the difference on labels, shelves, and pharmacy software. It's promoted by ISMP and FDA as a standard error-prevention tool, and on the exam it's the go-to answer for “which practice reduces LASA errors?”
- arrow_rightOther tested LASA safeguards: separating look-alike stock on the shelf, barcode scanning at dispensing, and indication checks (“does this drug match the patient's condition?”).
- arrow_rightBrand↔generic knowledge is itself a LASA defense — knowing Celebrex is celecoxib (an NSAID) and Celexa is citalopram (an SSRI) makes the swap obvious.
How should I study LASA pairs?
- arrow_rightLearn each drug's job first. A pair only confuses you when both names are hollow. Once “hydralazine = blood pressure” is solid, the pair resolves itself.
- arrow_rightQuiz the pair in both directions — “which one is the antihistamine?” and “what does hydrOXYzine treat?”
- arrow_rightWrite the Tall Man version once by hand. Physically writing hydrOXYzine cements which letters differ.
- arrow_rightThen drill them as flashcards. get the app free — the Top 200 deck covers the LASA drugs with their classes, uses, and mnemonics.
LASA drugs — FAQ
What is Tall Man lettering?
A safety convention that capitalizes the differing letters in confusable drug names (hydrOXYzine vs hydrALAZINE) so the difference stands out on labels and screens. It's recommended by ISMP and FDA.
Is clonidine the same as clonazepam?
No. Clonidine is a blood-pressure medication (an alpha-2 agonist, also used for ADHD); clonazepam is a Schedule IV benzodiazepine for seizures and panic disorder. They're a classic LASA pair.
How does the PTCE test LASA drugs?
Usually inside the Patient Safety domain (23.75% of the 2026 exam): identifying which drug in a pair matches a use, or choosing the safety practice — like Tall Man lettering or separating stock — that prevents the mix-up.
Drill the pairs until you can't confuse them
RxReflex turns the Top 200 drugs into fast flashcard rounds, a guided Learn path, pharmacy math, and 40+ cheat sheets. Free to start.
Keep studying
Drug Suffix Cheat Sheet~25 name endings that unlock hundreds of drugs — the fastest shortcut on the exam.
Sig Codes Cheat SheetEvery abbreviation you'll see on a prescription — plus the ten you must never write.
High-Alert Medications ListThe six drug classes that cause the most harm when something goes wrong — and the safeguards that stop it.Prefer a printable version? Grab “The PTCB Pass Code” free PDF — the highest-yield facts, formulas & traps on 22 pages.
Written and reviewed by the RxReflex Content Team. Educational use only — not medical advice. Exam policies and fees are set by PTCB — always confirm details at ptcb.org. Verify clinical specifics with your pharmacist or a current label source such as DailyMed. RxReflex is not affiliated with or endorsed by the Pharmacy Technician Certification Board (PTCB).