Penicillins & cephalosporins
The beta-lactams
Common bacterial infections — ear, throat, sinus, skin, urinary and respiratory.
Breaks the bacterial cell wall so the cell can't hold together.
The 4 penicillins & cephalosporins in the PTCB Top 200
| Generic | Brand | Common use |
|---|---|---|
| Amoxicillin | Amoxil | bacterial infections |
| Amoxicillin / Clavulanate | Augmentin | bacterial infections |
| Cephalexin | Keflex | skin, UTI infections |
| Cefdinir | Omnicef | bacterial infections |
Tap any generic name for its full drug guide — brand↔generic, side effects, interactions and the exam tip.
What to know for the exam
- check_circleAmoxicillin and cephalexin are among the most-dispensed antibiotics.
- check_circleClavulanate is added to amoxicillin to defeat bacterial resistance.
- check_circleMany oral suspensions in this group are reconstituted with water and then refrigerated.
- check_circleFinish the full course even once symptoms improve.
A documented penicillin allergy has to be checked before dispensing — some patients also react to cephalosporins.
Reconstituted suspensions have a limited beyond-use date, commonly 10 to 14 days depending on the product.
Drill penicillins & cephalosporins the way the PTCE asks them
RxReflex groups the Top 200 drugs into classes like this one, then quizzes you on brand↔generic, class, side effects and interactions. Plus a guided Learn path, pharmacy math and 40+ cheat sheets. Free to start.
Frequently asked
What drugs are in the penicillins & cephalosporins class? add
Amoxicillin, Amoxicillin / Clavulanate, Cephalexin, Cefdinir. All are in the PTCB Top 200.
What are penicillins & cephalosporins used for? add
Common bacterial infections — ear, throat, sinus, skin, urinary and respiratory.
How do penicillins & cephalosporins work? add
Breaks the bacterial cell wall so the cell can't hold together.
Last reviewed August 7, 2026. For education only — not medical advice. Not affiliated with or endorsed by the PTCB.