What the FDA labels say about taking them together
Penicillin g and probenecid
Penicillin g's FDA label of September 16, 2020 names probenecid in its drug interactions section; the probenecid label PlainMeds reads does not name penicillin g. The penicillin g label: “Penicillin blood levels may be prolonged by concurrent administration of probenecid which blocks the renal tubular secretion of penicillins.”
Check it at the source: the penicillin g FDA label on DailyMed (effective September 16, 2020, Sandoz Inc); the probenecid FDA label on DailyMed (effective January 5, 2021, Lannett Company, Inc.).
What does the penicillin g label say about probenecid?
Penicillin g label, drug interactionsPenicillin blood levels may be prolonged by concurrent administration of probenecid which blocks the renal tubular secretion of penicillins.
Source: FDA drug label (Penicillin G Potassium), Sandoz Inc, effective September 16, 2020 (SPL set 91950983-4884-40d1-abd8-bcc953d61b7f), via openFDA; the full label on DailyMed
What does the probenecid label say about penicillin g?
Probenecid's label (effective January 5, 2021) does not name penicillin g in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Probenecid), Lannett Company, Inc., effective January 5, 2021 (SPL set ab497fd8-00c3-4364-b003-b39d21fbdf38), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Penicillin g | Probenecid | |
|---|---|---|
| Labeled for | Bacterial infections | Gout |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.636 per tablet 500 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once