Prescription medicine
Cilastatin and imipenem Brand names: Primaxin
Cilastatin and imipenem (Primaxin) is a prescription medicine with an FDA approval on record since 1985. FDA's NDC Directory lists it from 2 generic labelers.
- Generic listed
- A presentation discontinued
Check it at the source: the cilastatin and imipenem FDA label on DailyMed (effective July 5, 2024, Merck Sharp & Dohme LLC); the NDA 50587 record on Drugs@FDA; every cilastatin and imipenem label on DailyMed.
Highlights of the record
FDA label of July 5, 2024; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
Used for
From the label: indications and usagePRIMAXIN for intravenous use is a combination of imipenem, a penem antibacterial, and cilastatin, a renal dehydropeptidase inhibitor, indicated for the treatment of the following serious infections caused by designated susceptible bacteria: Lower respiratory tract infections.
Forms and strengths
- 250 mg/20ml / 250 mg/20ml
- 500 mg/20ml / 500 mg/20ml
- 500 mg/100ml / 500 mg/100ml
- 500 mg / 500 mg
Injection (powder) for solution.
On the market
- Earliest approval on file
- November 26, 1985 Primaxin, Merck; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 5 first January 8, 1987; 2 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 3 of which 2 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- None current 1 past records
- Recalls by its makers (FDA)
- 0 since 2022 0 Class I among all firms' recalls; 1 more by firms not listed as its makers
- FAERS reports
- 4,053 through July 30, 2026
What is cilastatin and imipenem used for?
From the label: indications and usagePRIMAXIN for intravenous use is a combination of imipenem, a penem antibacterial, and cilastatin, a renal dehydropeptidase inhibitor, indicated for the treatment of the following serious infections caused by designated susceptible bacteria: Lower respiratory tract infections. ( 1.1 ) Urinary tract infections. ( 1.2 ) Intra-abdominal infections. ( 1.3 ) Gynecologic infections. ( 1.4 ) Bacterial septicemia. ( 1.5 ) Bone and joint infections. ( 1.6 ) Skin and skin structure infections. ( 1.7 ) Endocarditis. ( 1.8 ) Limitations of Use: PRIMAXIN is not indicated in patients with meningitis because safety and efficacy have not been established ( 1.9 ). […]
Conditions named in the indications of cilastatin and imipenem's FDA labels, with every medicine labeled for each:
From other cilastatin and imipenem labelsBacterial infections: Lower Respiratory Tract Infections PRIMAXIN for intravenous use is indicated for the treatment of lower respiratory tract infections caused by susceptible strains of Staphylococcus aureus (penicillinase-producing isolates), Acinetobacter …
Urinary tract infections: Infections (complicated and uncomplicated) PRIMAXIN is indicated for the treatment of urinary tract infections (complicated and uncomplicated) caused by susceptible strains of Enterococcus faecalis, Staphylococcus aureus …
FDA pharmacologic class: Penem Antibacterial and Renal Dehydropeptidase Inhibitor.
Source: FDA drug label (PRIMAXIN IV), Merck Sharp & Dohme LLC, effective July 5, 2024 (SPL set f41d8abd-7792-4918-1b93-bd83ea01955e), via openFDA; the full label on DailyMed
Is there a generic for cilastatin and imipenem (Primaxin)?
The FDA approved the first generic cilastatin and imipenem on January 8, 1987. 5 generic applications are approved; 2 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists cilastatin and imipenem from 2 labelers under a generic (ANDA) application and from 1 brand labeler. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1985 earliest approval on file
- 1987 first generic approved
- red ticks recalls
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
Is cilastatin and imipenem in shortage?
No cilastatin and imipenem presentation is listed as in shortage in the FDA Drug Shortage Database (read October 8, 2026); its 1 record is all marked to be discontinued, the latest updated January 8, 2026. ASHP keeps a separate shortage list, which can differ.
| Presentation | Company | Status | Updated |
|---|---|---|---|
| Primaxin, Injection, 500mg (NDC 0006-3516-59) | Merck Sharp & Dohme Corp. | To Be Discontinued | January 8, 2026 |
Every cilastatin and imipenem presentation in the FDA shortage database
Source: FDA Drug Shortage Database via openFDA, updated October 8, 2026
Has cilastatin and imipenem been recalled?
The FDA's Enforcement Report lists 1 recall naming cilastatin and imipenem since 2022: 0 Class I (the most serious), 1 Class II, 0 Class III; 0 still ongoing. 1 of them is by a firm that FDA's NDC Directory does not list as a maker of cilastatin and imipenem and that holds no application for it in Drugs@FDA, such as compounding pharmacies or bulk-ingredient suppliers; the recall notice names the product recalled. A recall names products and lots, not every product of the medicine.
| Started | Class | Company | Reason |
|---|---|---|---|
| December 27, 2022 | Class II | Sentara Infusion Services not a listed maker | Lack of sterility assurance |
Source: FDA Enforcement Report (drug recalls) via openFDA, through October 8, 2026
What does the cilastatin and imipenem label say about other medicines?
The cilastatin and imipenem label names 4 other medicines in its interaction, contraindication or warning sections. The labels of 1 other medicine name cilastatin and imipenem. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Divalproex | drug interactions | Valproic acid/divalproex sodium: Concomitant use with PRIMAXIN is generally not recommended. |
| Ganciclovir | drug interactions | DRUG INTERACTIONS Ganciclovir: Generalized seizures have been reported in patients who received ganciclovir. |
| Probenecid | drug interactions | Concomitant administration of PRIMAXIN and probenecid results in increases in the plasma level and half-life of imipenem. |
| Valproic acid | drug interactions | Valproic acid/divalproex sodium: Concomitant use with PRIMAXIN is generally not recommended. |
Source: FDA drug label (PRIMAXIN IV), Merck Sharp & Dohme LLC, effective July 5, 2024 (SPL set f41d8abd-7792-4918-1b93-bd83ea01955e), via openFDA; the full label on DailyMed
What do FAERS reports show for cilastatin and imipenem?
The FDA Adverse Event Reporting System holds 4,053 reports that list cilastatin and imipenem among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 954 are coded as a death and 1,832 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as cilastatin and imipenem?
22 other medicines are given the same way (intravenous) and in the same FDA class as cilastatin and imipenem or labeled mainly for the same use (bacterial infections), the same class first. Bacterial infections lists all 51 medicines labeled for it, by any route. The first 8 are below. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (intravenous) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Meropenem and vaborbactam | Urinary tract infections | none listed | n/a | No current entry |
| Vancomycin | Bacterial infections | 21 labelers | $2.31 per vial 500 mg vial | A presentation being discontinued |
| Piperacillin and tazobactam | Bacterial infections | 15 labelers | $3.49 per vial 3.375 g vial | A presentation being discontinued |
| Levofloxacin | Bacterial infections, Urinary tract infections | 8 labelers | n/a | No current entry |
| Clindamycin | Bacterial infections | 6 labelers | n/a | In shortage |
| Ampicillin | Bacterial infections, Urinary tract infections | 11 labelers | n/a | A presentation being discontinued |
| Linezolid | Bacterial infections | 9 labelers | n/a | No current entry |
| Cefoxitin | Bacterial infections, Urinary tract infections | 5 labelers | n/a | No current entry |
Every medicine labeled for the same conditions as cilastatin and imipenem
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
What next?
- Alternatives to cilastatin and imipenem
- 22 medicines for the same use
- Other penem antibacterials
- the pharmacologic class, with prices and generics
- Cilastatin and imipenem side effects
- the label's list beside FAERS reports
- Cilastatin and imipenem shortage record
- every presentation, company and date
- Check an interaction
- what two or more labels say about each other