Imipenem and Cilastatin Injection
Imipenem and cilastatin is a combination antibiotic given by IV infusion to treat serious bacterial infections including lung, urinary tract, abdominal, skin, bone, gynecologic infections, blood infections (bacterial septicemia), and endocarditis.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 5 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Imipenem and Cilastatin Injection: Patient Information Guide
A plain-language walkthrough of Imipenem and Cilastatin Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Imipenem and cilastatin for injection is a broad-spectrum antibiotic combination used intravenously to treat a wide range of serious bacterial infections. It is approved for the following conditions:
- Lower respiratory tract infections (e.g., pneumonia caused by susceptible bacteria)
- Urinary tract infections — both complicated and uncomplicated
- Intra-abdominal infections (infections inside the abdomen)
- Gynecologic infections
- Bacterial septicemia (serious bacterial bloodstream infection)
- Bone and joint infections
- Skin and skin structure infections
- Endocarditis (infection of the lining of the heart) caused by susceptible Staphylococcus aureus
- It is not approved for meningitis, and is not recommended for CNS infections in children (due to seizure risk) or in children under 30 kg with kidney impairment
⚙️How it works▾
Imipenem kills bacteria by blocking the construction of their outer cell walls — without an intact wall, bacteria cannot survive. Cilastatin does not fight bacteria directly; instead, it prevents the kidneys from breaking down imipenem too rapidly. This allows imipenem to reach and maintain effective levels throughout the body and in the urine, making the combination especially useful for urinary tract infections as well as infections in other tissues.
Because imipenem penetrates well into many body tissues — including the lungs, bone, peritoneal fluid, and skin — it can reach infections in a wide variety of locations. This broad reach is part of what makes it valuable for serious or complicated infections.
💊How it's taken▾
Imipenem and cilastatin is given by intravenous infusion only, administered by a healthcare professional — typically in a hospital or infusion setting. It is infused multiple times per day, commonly every 6 to 8 hours, depending on the type and severity of infection and the patient's kidney function.
- Doses are adjusted based on kidney function — lower kidney function requires a reduced dose
- Patients with very low kidney function (creatinine clearance below 15 mL/min) should not receive this medication unless they are on hemodialysis
- In pediatric patients, dosing is weight-based and age-specific; it is not used in children with CNS infections or in children under 30 kg with kidney problems
- Follow your prescriber's dosing schedule exactly — do not adjust the dose or frequency on your own
🤒Side effects — in detail▾
The most commonly reported side effects in adults include:
- Phlebitis (vein inflammation) or pain at the IV site
- Nausea, vomiting, or diarrhea
- Skin rash or itching
- Fever
- Low blood pressure (hypotension)
- Dizziness or drowsiness
- Redness or hardening of the vein at the infusion site
More serious reactions — including seizures, severe allergic reactions (anaphylaxis), and Clostridioides difficile-associated diarrhea (C. diff, a serious gut infection) — require immediate medical attention. Rare but serious liver effects (including liver failure) and severe skin reactions (such as Stevens-Johnson syndrome) have also been reported after the drug reached the market.
⚠️Warnings & precautions▾
- Seizure risk: Seizures, muscle twitching (myoclonus), and confusion have occurred — most often in people with existing brain or nervous system conditions, reduced kidney function, or doses that are too high. If any of these symptoms occur, the medical team will reassess treatment immediately.
- Severe allergic reactions: Serious and sometimes fatal allergic (anaphylactic) reactions have been reported, particularly in people with a history of allergy to penicillins, cephalosporins, or other beta-lactam antibiotics. If an allergic reaction occurs, the infusion must be stopped immediately.
- Valproic acid interaction: Using this medication with valproic acid or divalproex sodium (seizure medications) can cause those drug levels to fall dangerously low, increasing the risk of breakthrough seizures. This combination is generally not recommended.
- C. difficile diarrhea (CDAD): Like all antibiotics, this drug can disturb the normal gut bacteria and lead to a serious intestinal infection. Diarrhea during or after treatment — even up to two months later — should be evaluated by a doctor.
- Drug-resistant bacteria: Using antibiotics when not truly needed can lead to resistant bacteria. This medication should only be used for confirmed or strongly suspected bacterial infections.
🔀What it interacts with▾
Tell your healthcare team about all medications you take. Key interactions to know about:
- Valproic acid / divalproex sodium: Imipenem/cilastatin can significantly reduce the blood levels of these seizure medications, potentially causing breakthrough seizures — this combination is generally not recommended
- Ganciclovir (antiviral used for CMV infections): the combination raises the risk of generalized seizures and should be avoided unless the benefit clearly outweighs the risk
- Probenecid (used for gout): increases how much imipenem stays in the bloodstream and for how long — this combination is not recommended
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Tell your doctor if you have a known allergy to penicillins, cephalosporins, or any other beta-lactam antibiotic — serious cross-reactions can occur
- Tell your doctor if you have a history of seizures or any neurological condition — your risk of seizure-related side effects is higher
- Tell your doctor if you have kidney disease — your dose must be carefully adjusted, and kidney function should be monitored during treatment
- If you are pregnant, discuss the risks and benefits with your doctor; animal studies showed some embryo loss at doses close to the human dose
- If you are breastfeeding, discuss with your doctor — there is not enough data on whether the drug passes into breast milk
- In children under 30 kg with kidney impairment, this medication is not recommended
- In children with CNS (brain/nervous system) infections, this medication is not recommended due to seizure risk
- Older adults should be monitored carefully, as reduced kidney function (common with aging) increases the risk of toxic effects including seizures
- Patients with very low kidney function (creatinine clearance below 15 mL/min) should not receive this drug unless hemodialysis is in place
🚑If you take too much▾
If too much of this medication is given, the infusion should be stopped and supportive medical care provided. Imipenem and cilastatin can be removed from the body through hemodialysis (a kidney-filtering procedure), which may be used in an overdose situation.
📡Pharmacodynamics — effects in the body▾
Imipenem works by disrupting bacterial cell wall synthesis — the process bacteria need to build and maintain their outer structure. Without an intact cell wall, bacteria die. Cilastatin prevents the kidneys from inactivating imipenem before it can do its job, preserving effective antibiotic concentrations throughout the body. Together, they maintain antibacterial activity in both the blood and the urine.
🔬Pharmacokinetics — how your body processes it▾
When given as an IV infusion, imipenem reaches peak blood levels quickly — within minutes of the infusion completing — and then clears from the blood within 4 to 6 hours. Both imipenem and cilastatin have a plasma half-life (the time it takes the body to clear half the drug) of approximately 1 hour. About 70% of each drug is eliminated through the urine within 10 hours. Imipenem binds loosely to blood proteins (about 20%), while cilastatin binds somewhat more (about 40%), and imipenem distributes well into many body tissues including the lungs, bone, peritoneal fluid, and skin. Because both drugs are removed by the kidneys, patients with impaired kidney function need dose adjustments, and both can be cleared from the body by hemodialysis.
📦How to store it▾
stored at 20° to 25°C (68° to 77°F) .
📄 Written from Imipenem and Cilastatin Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Imipenem and Cilastatin Injection — the kind of thing our pharmacy team would talk through with you at the counter.
Why am I getting an antibiotic through an IV instead of just taking a pill? ▾
What side effects should I actually watch out for during my infusion? ▾
I take valproic acid for my seizures. Is that a problem with this antibiotic? ▾
I got diarrhea after my infusion — should I be worried? ▾
I have kidney problems — does that affect how I get this medication? ▾
How long will I need to be on this antibiotic? ▾
Is Imipenem and Cilastatin Injection available over the counter? ▾
When was Imipenem and Cilastatin Injection first available? ▾
Who makes Imipenem and Cilastatin Injection? ▾
💬 Answers drafted from Imipenem and Cilastatin Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Imipenem and Cilastatin Injection comes
Imipenem and Cilastatin Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Treats serious bacterial infections including lower respiratory tract, urinary tract, intra-abdominal, gynecologic, bone and joint, and skin infections
- Treats bacterial septicemia (serious bloodstream infection)
- Treats endocarditis (infection of the heart's inner lining) caused by susceptible Staphylococcus aureus
- Not approved for meningitis; not recommended for CNS infections in children due to seizure risk
- Primaxin is given only as an intravenous (IV) infusion — never injected directly without dilution
- The reconstituted vial must be diluted in an appropriate infusion solution before administration; the undiluted suspension must not be given by direct IV injection
- After mixing, the solution may be colorless to yellow — variation in color within this range does not affect potency
- Once prepared, the solution should be used within 4 hours at room temperature or within 24 hours if refrigerated; do not freeze
📊 Imipenem and Cilastatin Injection across the U.S. market
How Imipenem and Cilastatin Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Imipenem and Cilastatin Injection is used
A general measure of how commonly Imipenem and Cilastatin Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Imipenem and Cilastatin Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Imipenem and Cilastatin Injection prescribed? Of the 1,596 medications we measure, Imipenem and Cilastatin Injection ranks #1,218 by Medicaid prescriptions — more than 24% of them.
Utilization by Imipenem and Cilastatin Injection product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
cilastatin 500 MG / imipenem 500 MG Injection Most dispensed
Summed across the 5 of 10 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1726214
cilastatin 250 MG / imipenem 250 MG Injection
Summed across the 1 of 8 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1726204
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Imipenem and Cilastatin Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 6 of 18 listed Imipenem and Cilastatin Injection NDCs with Medicaid activity.
🔍 Compare Imipenem and Cilastatin Injection products
A representative set of FDA-listed product records for Imipenem and Cilastatin Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| IMIPENEM 250 mg/20 mL; CILASTATIN SODIUM 250 mg/20 mL | Intravenous | Fresenius Kabi USA, LLC × 3 listings | ANDA | View NDC → |
| IMIPENEM 500 mg/20 mL; CILASTATIN SODIUM 500 mg/20 mL | Intravenous | Fresenius Kabi USA, LLC × 3 listings | ANDA | View NDC → |
| IMIPENEM 500 mg/100 mL; CILASTATIN SODIUM 500 mg/100 mL | Intravenous | Merck Sharp & Dohme LLC | NDA | View NDC → |
| 500; 500 mg/100 mL; mg/100 mL | Intravenous | Merck Sharp & Dohme LLC × 2 listings | NDA | View NDC → |
| IMIPENEM ANHYDROUS 500 mg/1; CILASTATIN SODIUM 500 mg | Intravenous | WG Critical Care, LLC | ANDA | View NDC → |
| 500; 500 mg/1; mg | Intravenous | WG Critical Care, LLC × 2 listings | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| IMIPENEM 1 kg/kg; CILASTATIN 1 kg/kg | — | ACS Dobfar S.p.A | DRUG FOR FURTHER PROCESSING | View NDC → |
Showing 13 of 13 products — FDA National Drug Code Directory. See every product, package size and price: browse all 13 Imipenem and Cilastatin Injection NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Imipenem and Cilastatin Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Imipenem and Cilastatin Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Imipenem and Cilastatin Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one exact multiple-ingredient concept (MIN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). A product with a different ingredient combination belongs on a different page.
RxCUI 34482 1 dose form · 2 strengths
-
Dose form (SCDF) Injection RxCUI 1726203In current FDA listingsClinical drug / strength (SCD) cilastatin 250 MG / imipenem 250 MGRxCUI 1726204cilastatin 500 MG / imipenem 500 MGRxCUI 1726214
Look up RxCUI 34482 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Imipenem and Cilastatin Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Imipenem and Cilastatin Injection belongs to the Renal Dehydropeptidase Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 5 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Merck Sharp & Dohme LLC is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.