FDA pharmacologic class
Penicillins
8 medicines are in FDA's class of penicillin-class antibacterials (penicillins): amoxicillin (Amoxil), ampicillin, penicillin v, nafcillin, penicillin g (Pfizerpen), oxacillin, dicloxacillin and penicillin g benzathine (Bicillin); 5 combination products also contain one. 10 of the 13 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is amox-clav 600-42.9 mg/5 ml sus at $0.0693 per mL (NADAC).
Which medicines are penicillins?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Amoxicillin | Amoxil | 38 labelers | $0.0788 per capsule 500 mg capsule | No | No current entry | 12 |
| Amoxicillin and clavulanate | Augmentin | 31 labelers | $0.0693 per mL 600-42.9 mg/5 mL sus | No | No current entry | 5 |
| Piperacillin and tazobactam | Zosyn | 15 labelers | $3.49 per vial 3.375 g vial | No | A presentation being discontinued | 17 |
| Ampicillin | none listed | 17 labelers | $0.441 per capsule 500 mg capsule | No | A presentation being discontinued | 3 |
| Penicillin v | none listed | 17 labelers | $0.0985 per tablet 500 mg tablet | No | No current entry | 4 |
| Ampicillin and sulbactam | Unasyn | 12 labelers | n/a | No | No current entry | 17 |
| Nafcillin | none listed | 9 labelers | n/a | No | No current entry | 3 |
| Penicillin g | Pfizerpen | 8 labelers | n/a | No | No current entry | 1 |
| Oxacillin | none listed | 5 labelers | n/a | No | No current entry | 4 |
| Dicloxacillin | none listed | 6 labelers | $0.590 per capsule 250 mg capsule | No | No current entry | 2 |
| Penicillin g benzathine | Bicillin | none listed | n/a | Yes | In shortage | 2 |
| Penicillin g benzathine and penicillin g procaine | Bicillin | none listed | n/a | Yes | No current entry | 0 |
| Amoxicillin and omeprazole and rifabutin | Talicia | none listed | $4.88 per capsule 10-250-12.5 mg capsule | No | No current entry | 0 |
Source: FDA Established Pharmacologic Class (NDC Directory, openFDA); CMS NADAC of October 7, 2026; FDA shortages and recalls (FDA files October 8, 2026)
What do pharmacies pay?
Each medicine's most widely listed form, per unit, in the NADAC survey: what pharmacies paid, not what a patient pays; strengths differ, so compare like with like.
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price