Imipenem

Imipenem and Cilastatin for Injection (I.V.) is a combination of imipenem and cilastatin. Imipenem is a penem antibacterial drug [see Microbiology ( 12.4 )] .

• Imipenem and Cilastatin for Injection, USP 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.ICD-10: N39.0

• Imipenem and Cilastatin for Injection (I.V.) is contraindicated in patients who have shown hypersensitivity to any component of this product.contraindicated

The dosage of Imipenem and Cilastatin for Injection (I.V.) in adult patients should be based on suspected or confirmed pathogen susceptibility ( 2.1 ). For adult patients with normal renal function (creatinine clearance of greater than or equal to 90 mL/min), the recommended dosage regimens are: 500 mg every 6 hours OR 1,000 mg every 8 hours OR 1,000 mg every 6 hours ( 2.1 ). See full prescribing information for dosage recommendations in pediatric patients ( 2.2 ). A reduction in dose must be made for a patient with a creatinine clearance of less than 90 mL/min ( 2.3 ). Patients with creatinine clearances of less than 15 mL/min should not receive Imipenem and Cilastatin for Injection (I.V.) unless hemodialysis is instituted within 48 hours ( 2.4 ). Reconstitute Imipenem and Cilastatin for Injection, USP (I.V.) vial with appropriate diluent and dilute the reconstituted suspension with an appropriate infusion solution before administering by intravenous infusion ( 2.5 ). 2.1 Dosage in Adults For Intravenous Injection Only The dosage of Imipenem and Cilastatin for Injection (I.V.) in adult patients should be based on suspected or confirmed pathogen susceptibility as shown in Table 1 below. The dosage recommendations for Imipenem and Cilastatin for Injection (I.V.) represent the quantity of imipenem to be administered. An equivalent amount of cilastatin is also present in the solution. These doses should be used for patients with creatinine clearance of greater than or equal to 90 mL/min.

Hypersensitivity Reactions: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving therapy with beta-lactams. If an allergic reaction to Imipenem and Cilastatin for Injection (I.V.) occurs, discontinue the drug immediately ( 5.1 ). Seizure Potential: Seizures and other CNS adverse reactions, such as confusional states and myoclonic activity, have been reported during treatment with Imipenem and Cilastatin for Injection (I.V.). If focal tremors, myoclonus, or seizures occur, patients should be evaluated neurologically, placed on anticonvulsant therapy if not already instituted, and the dosage of Imipenem and Cilastatin for Injection (I.V.) re-examined to determine whether it should be decreased, or the antibacterial drug discontinued ( 5.2 ). Increased Seizure Potential Due to Interaction with Valproic Acid: Co-administration of Imipenem and Cilastatin for Injection (I.V.), to patients receiving valproic acid or divalproex sodium results in a reduction in valproic acid concentrations. The valproic acid concentrations may drop below the therapeutic range as a result of this interaction, therefore increasing the risk of breakthrough seizures. The concomitant use of Imipenem and Cilastatin for Injection (I.V.) and valproic acid/divalproex sodium is generally not recommended ( 5.3 , 7.3 ). Clostridioides difficile-Associated Diarrhea (CDAD): has been reported with use of Imipenem and Cilastatin for Injection (I.V.) and may range in severity from mild diarrhea to fatal colitis. Evaluate if diarrhea occurs ( 5.4 ).

The following serious adverse reactions are described in greater detail in the Warnings and Precautions section. Hypersensitivity Reactions [see Warnings and Precautions ( 5.1 )] Seizure Potential [see Warnings and Precautions ( 5.2 )] Increased Seizure Potential Due to Interaction with Valproic Acid [see Warnings and Precautions ( 5.3 )] Clostridioides difficile -Associated Diarrhea (CDAD) [see Warnings and Precautions ( 5.4 )] Development of Drug-Resistant Bacteria [see Warnings and Precautions ( 5.5 )] The most frequently occurring adverse reactions (≥ 0.2%) in adults were phlebitis, nausea, diarrhea, vomiting, rash, pain injection site, fever, hypotension, seizures, erythema at injection site, dizziness, pruritus, vein induration, urticaria, somnolence ( 6.1 ). The most frequently occurring adverse reactions (> 1%) in pediatric patients greater than or equal to 3 months of age were diarrhea, rash, phlebitis, gastroenteritis, vomiting, IV site irritation, urine discoloration ( 6.1 ). The most frequently occurring adverse reactions (> 1%) in neonates to 3 months of age were convulsions, diarrhea, oliguria/anuria, oral candidiasis, rash, tachycardia ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Renal Impairment: Dosage adjustment is necessary in patients with renal impairment ( 2.3 ). Adult patients with creatinine clearances of less than or equal to 30 mL/min, whether or not undergoing hemodialysis, had a higher risk of seizure activity than those without impairment of renal function ( 5.2 ). Therefore, close adherence to the dosing guidelines and regular monitoring of creatinine clearance for these patients is recommended ( 8.6 ). 8.1 Pregnancy Risk Summary Available data from a small number of postmarketing cases with Imipenem and Cilastatin for Injection (I.V.) use in pregnancy are not sufficient to identify any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes. Developmental toxicity studies with imipenem and cilastatin sodium (alone or in combination) administered to mice, rats, rabbits, and monkeys at doses 0.4 to 2.9 times the recommended human dose (RHD), (based on body surface area), showed no drug-induced fetal malformations. Embryofetal development studies with imipenem/cilastatin administered to cynomolgus monkeys at doses similar to the RHD (based on body surface area) showed an increase in embryonic loss (see Data ) . The background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

Metabolism

Intravenous infusion of Imipenem and Cilastatin for Injection (I.V.) over 20 minutes results in peak plasma levels of imipenem antimicrobial activity that range from 21 to 58 mcg/mL for the 500 mg dose, and from 41 to 83 mcg/mL for the 1,000 mg dose. At these doses, plasma levels of imipenem antimicrobial activity decline to below 1 mcg/mL or less in 4 to 6 hours.

In the case of overdosage, discontinue Imipenem and Cilastatin for Injection (I.V.), treat symptomatically, and institute supportive measures as required. Imipenem and Cilastatin for Injection (I.V.) is hemodialyzable.

• Nov 26, 1985NDANDA050587Merck
• Dec 21, 2011ANDAANDA090577Acs Dobfar
• Jul 16, 2019NDANDA212819Msd Merck Co
• Dec 12, 2019ANDAANDA207594Hq Spclt Pharma

Reference statistics from the openFDA drug-shortage dataset. For a live view, consult the FDA database directly. Not clinical guidance.

• Primaxin, Injection, 500mg (NDC 0006-3516-59)To be discontinued
  Sponsor: Merck Sharp & Dohme Corp.
  Updated Jan 8, 2026

1. 1Drug Ineffective3538.6%
2. 2Product Use In Unapproved Indication3037.4%
3. 3Off Label Use2616.4%
4. 4Pyrexia2115.1%
5. 5Convulsion1914.7%
6. 6Pneumonia1603.9%
7. 7Sepsis1543.8%
8. 8Thrombocytopenia1453.5%
9. 9Death1373.3%
10. 10Septic Shock1293.1%
11. 11Nausea1233.0%
12. 12Pathogen Resistance1223.0%
13. 13Vomiting1142.8%
14. 14Respiratory Failure1132.8%
15. 15Anaemia1112.7%

Recent PubMed references pinned to Imipenem as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Antimicrobial activity of ceftolozane/tazobactam, imipenem/relebactam, and comparators against Gram-negative pathogens collected in Arabian Gulf countries: SMART 2020-2024.
  Frontiers in cellular and infection microbiology · 2026 · Wise MG, Alekseeva I, Siddiqui F, et al.
  PMID 42205475DOI 10.3389/fcimb.2026.1827575
• Physiologically based pharmacokinetic modeling and dose adjustment of imipenem in pediatric patients with renal impairment.
  Frontiers in cellular and infection microbiology · 2026 · Feng C, Xiao P, Qu Y, et al.
  PMID 42180250DOI 10.3389/fcimb.2026.1798911
• Comparative Outcomes of Meropenem and Imipenem in Multidrug-Resistant Pulmonary Infections: A Prospective Cohort Study.
  Journal of visualized experiments : JoVE · 2026 · Jin XM, Qiao J, Wang F, et al.
  PMID 42149844DOI 10.3791/70596
• Efficacy and safety of cefepime-nacubactam and aztreonam-nacubactam compared with imipenem-cilastatin for complicated urinary tract infection or acute uncomplicated pyelonephritis (Integral-1): a double-blind, randomised phase 3 trial.
  Lancet (London, England) · 2026 · Takahashi S, Tateda K, Yanagihara K, et al.
  PMID 42134354DOI 10.1016/S0140-6736(26)00596-9
• Hydrogen-Bonding Changes Cause Differences in Imipenem Breakdown Activity in OXA-48 Variants.
  Journal of chemical information and modeling · 2026 · Wang D, Mulholland AJ, Spencer J, et al.
  PMID 42018524DOI 10.1021/acs.jcim.6c00223
• A multicenter, randomized, double-blind, imipenem/cilastatin-controlled clinical study of cefiderocol for the treatment of complicated urinary tract infections caused by gram-negative pathogens in chinese adults.
  International journal of antimicrobial agents · 2026 · Yuan J, Fan D, Wu H, et al.
  PMID 41997432DOI 10.1016/j.ijantimicag.2026.107812
• Emergence of KPC-producing Pseudomonas aeruginosa in Spain: insights into an outbreak and resistance to the novel carbapenem/β-lactamase inhibitor combinations imipenem/relebactam and meropenem/vaborbactam.
  Antimicrobial agents and chemotherapy · 2026 · Pérez-Rodríguez G, Aja-Macaya P, González-Pinto L, et al.
  PMID 41891864DOI 10.1128/aac.01657-25
• Molecular insights into the oxidative perturbation of VIM-2 metallo-β-lactamase: Active site remodeling restores imipenem susceptibility in Pseudomonas aeruginosa.
  Microbial pathogenesis · 2026 · Ibrahim B, Ghafil JA, Abdullah ZA, et al.
  PMID 41771381DOI 10.1016/j.micpath.2026.108411

The 10 most recently updated of 114 ClinicalTrials.gov registrations naming Imipenem as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• The Effect of Rifabutin in Mycobacterium Abscessus With Inducible Clarithromycin Resistance
  Recruiting · Phase 4 · Interventional · 60 enrolled · National Taiwan University Hospital
  NCT07514364updated 2026-06-10
• Bacteriophage Therapy for Mycobacterium Abscessus Pulmonary Infection
  Enrolling by invitation · Phase 1 · Interventional · 1 enrolled · Vancouver Coastal Health
  NCT07228702updated 2026-06-03
• Preventive Effect of Prophylactic Oral Antibiotics Against Cholangitis After Kasai Portoenterostomy
  Recruiting · Interventional · 356 enrolled · Children's Hospital of Fudan University
  NCT05925309updated 2026-05-15
• Finding the Optimal Regimen for Mycobacterium Abscessus Treatment
  Recruiting · Phase 2 · Phase 3 · Interventional · 300 enrolled · The University of Queensland
  NCT04310930updated 2026-05-11
• Comparing Efficacy and Safety of (Meropenem + Colistin) Versus (Imipenem/Cilastatin + Tigecycline) on Eradication of Multi-Drug Resistance Bacteria
  Not yet recruiting · Phase 2 · Interventional · 60 enrolled · Ain Shams University
  NCT07524920updated 2026-04-13
• PHASE II SINGLE-CENTER, RANDOMIZED, OPEN-LABEL, PROSPECTIVE, STUDY TO DETERMINE THE IMPACT OF SERIAL PROCALCITONIN
  Completed · Phase 2 · Interventional · 100 enrolled · M.D. Anderson Cancer Center
  NCT04983901updated 2026-04-06
• Testing a Novel Combination Treatment (Arm D) Versus Standard of Care for Intensive Phase Treatment for Mycobacterium Abscessus Pulmonary Disease in People With or Without Cystic Fibrosis in the Finding the Optimal Regimen for Mycobacterium Abscessus Treatment (FORMaT) Adaptive Platform Trial
  Not yet recruiting · Phase 2 · Interventional · 300 enrolled · The University of Queensland
  NCT07485010updated 2026-03-20
• A Study of Oral Tebipenem Pivoxil Hydrobromide (TBP-PI-HBr) Compared to Intravenous Imipenem-cilastatin in Participants With Complicated Urinary Tract Infection (cUTI) or Acute Pyelonephritis (AP)
  Completed · Phase 3 · Interventional · 1,690 enrolled · Spero Therapeutics
  NCT06059846updated 2026-03-10
• Safety, Tolerability, Efficacy and Pharmacokinetics of Imipenem/Cilastatin/Relebactam (MK-7655A) in Pediatric Participants With Gram-negative Bacterial Infection (MK-7655A-021)
  Completed · Phase 2 · Phase 3 · Interventional · 115 enrolled · Merck Sharp & Dohme LLC
  NCT03969901updated 2026-02-05
• Percutaneous Transcatheter Genicular Embolization in Osteoarthritis
  Recruiting · Interventional · 20 enrolled · Masarykova Nemocnice v Usti nad Labem, Krajska Zdravotni a.s.
  NCT07361198updated 2026-02-04

Frequently asked questions

How does Imipenem work?

Imipenem and Cilastatin for Injection (I.V.) is a combination of imipenem and cilastatin. Imipenem is a penem antibacterial drug [see Microbiology ( 12.4 )] .

What is Imipenem used for?

According to FDA labeling, Imipenem carries indications including: Imipenem and Cilastatin for Injection, USP 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.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Imipenem?

Imipenem is classified as Transpeptidase Inhibitors, Decreased Cell Wall Synthesis & Repair.

What are the brand names for Imipenem?

Imipenem is marketed under brand names including Primaxin, Recarbrio.

What are the contraindications for Imipenem?

Imipenem labeling lists contraindications including: Imipenem and Cilastatin for Injection (I.V.) is contraindicated in patients who have shown hypersensitivity to any component of this product.. Always consult the full prescribing information and a clinician.