Prescription medication · Carbapenem Antibiotic Combination

imipenem/cilastatin

Also sold as Primaxin. Primaxin treats serious infections like lung infections and urinary tract infections.

Data updated 2026-05-15

630
FDA reports
2
InteractionsFew interactions
In shortage
FDA status

What the data shows

imipenem/cilastatin (Primaxin) is a prescription Carbapenem Antibiotic Combination, with 630 FDA adverse-event reports on file, with 2 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

imipenem/cilastatin (Primaxin) is a prescription Carbapenem Antibiotic Combination. Primaxin treats serious infections like lung infections and urinary tract infections.

Primaxin is a strong antibiotic medicine. It fights serious infections in your body caused by certain bacteria.

Verify with FDA → · CMS NADAC pricing →

Drug Shortage Alert

imipenem/cilastatin is currently listed as to be discontinued by the FDA. Affected manufacturer: Merck Sharp & Dohme Corp..

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What it does

Primaxin treats serious infections like lung infections and urinary tract infections.

Common side effects

Phlebitis (vein irritation), Nausea, Diarrhea

Key warnings

Primaxin can cause serious allergic reactions.

The sections below are summarized in plain English from imipenem/cilastatin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Primaxin has two medicines: imipenem and cilastatin. Imipenem kills bacteria by stopping them from building cell walls. Cilastatin helps imipenem work better by preventing its breakdown in your kidneys.

Side Effects (from patient reports)

Based on 630 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for imipenem/cilastatin, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS)

Serious Warnings

Primaxin can cause serious allergic reactions. Tell your doctor if you are allergic to any beta-lactam antibiotics like penicillins or cephalosporins. Primaxin can also cause seizures, especially if you have a brain problem or kidney problems. It can also cause severe diarrhea from C. difficile. Using Primaxin with valproic acid may cause seizures.

Known Drug Interactions

moderate probenecid

Probenecid: Concomitant administration of PRIMAXIN and probenecid results in increases in the plasma level and half-life of imipenem. 7.2 Probenecid Concomitant administration of PRIMAXIN and probenecid results in increases in the plasma level and half-life of imipenem. Therefore, it is not recommended that probenecid be given concomitantly with PRIMAXIN.

Mechanism: Probenecid keeps imipenem in your blood for a longer time and at higher levels than usual.

minor ganciclovir

7 DRUG INTERACTIONS Ganciclovir: Generalized seizures have been reported in patients who received ganciclovir. 7.1 Ganciclovir Generalized seizures have been reported in patients who received ganciclovir and PRIMAXIN.

Mechanism: Using these two drugs at the same time can increase the chance of having a seizure.

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What should I tell my doctor before taking Primaxin?
Tell your doctor if you are allergic to any medicines, especially penicillins or cephalosporins. Also, tell them if you have kidney problems, brain problems, or seizures.
Can Primaxin cause seizures?
Yes, Primaxin can cause seizures, especially in people with brain disorders or kidney problems.
What if I get diarrhea while taking Primaxin?
Tell your doctor right away if you get diarrhea, especially if it is watery or bloody. It could be a sign of a serious infection.
Can I take Primaxin if I am allergic to penicillin?
You should tell your doctor if you are allergic to penicillin before taking Primaxin. There is a chance you could also be allergic to Primaxin.
Does Primaxin interact with other medications?
Yes, Primaxin can interact with certain medicines, like ganciclovir, probenecid, and valproic acid. Tell your doctor about all the medicines you take.
How will I receive Primaxin?
Primaxin is given to you through an IV into your vein.
What if I feel nauseous during the IV infusion?
Tell the nurse if you feel sick to your stomach. They can slow down the infusion rate.
Is Primaxin safe for children?
Primaxin is not recommended for children with central nervous system infections or kidney problems.
How long will I need to take Primaxin?
Your doctor will decide how long you need to take Primaxin based on your infection.
What if my symptoms get worse while taking Primaxin?
Tell your doctor right away if your symptoms get worse or if you develop new symptoms.
What are the common side effects of imipenem/cilastatin?
The registry lists Phlebitis (vein irritation), Nausea, Diarrhea, Vomiting, Rash among the most-reported FAERS reaction terms for imipenem/cilastatin. The compiled record contains 630 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does imipenem/cilastatin interact with other medications?
The registry has 2 documented interaction rows for imipenem/cilastatin. Notable source-record pairings include probenecid, ganciclovir. These rows are not a complete medication review.
What drug class is imipenem/cilastatin?
imipenem/cilastatin belongs to the Carbapenem Antibiotic Combination drug class. It requires a prescription (Rx). Primaxin treats serious infections like lung infections and urinary tract infections.
What pregnancy or breastfeeding source fields are listed for imipenem/cilastatin?
The FDA label for imipenem/cilastatin contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.
Is imipenem/cilastatin currently in shortage?
Yes, imipenem/cilastatin is currently listed as to be discontinued by the FDA. Affected manufacturer: Merck Sharp & Dohme Corp.. Visit the FDA Drug Shortages database for the latest updates.

Related Medications in Carbapenem Antibiotic Combination

Other drugs grouped near imipenem/cilastatin - same-class peers and common alternatives.

amikacin

Amikin

Amikacin is an antibiotic medicine.

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amoxicillin

Amoxil

Amoxicillin and Clavulanate Potassium is a combination medicine used to fight bacterial infections.

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amoxicillin/clavulanate

Augmentin

Augmentin is a combination of two medicines, amoxicillin and clavulanate.

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ampicillin/sulbactam

Unasyn

Unasyn is a combination of two antibiotics that fights bacteria in your body.

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azithromycin

Zithromax, Z-Pack

Azithromycin is an antibiotic that fights bacteria.

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What the FDA Data Shows for imipenem/cilastatin

The FDA label for imipenem/cilastatin (sold under brand names such as Primaxin) classifies it as a prescription-only medication in the Carbapenem Antibiotic Combination class. Primaxin treats serious infections like lung infections and urinary tract infections. Official labeling lists 15 commonly reported side effects, including Phlebitis (vein irritation), Nausea, Diarrhea.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 630 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. Acquisition-cost data is surveyed weekly by CMS and updated as manufacturers report changes.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Shortage status: FDA Drug Shortages Database.

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: July 5, 2024

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Read our methodology - how this data is sourced, computed, and verified.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page