Relebactam

Relebactam is a novel antibiotic being studied in clinical trials for treating various bacterial infections, particularly those caused by resistant organisms. This article summarizes key findings from several clinical trials evaluating the safety, efficacy, and pharmacokinetics of relebactam, typically used in combination with imipenem and cilastatin, for conditions like complicated urinary tract infections, intra-abdominal infections, and pneumonia.

Table of Contents

What is Relebactam?

Relebactam is a new medication that belongs to a class of drugs called beta-lactamase inhibitors. It is not used alone but is combined with two other antibiotics, imipenem and cilastatin, to form a powerful combination antibiotic known as imipenem/cilastatin/relebactam. This combination is marketed under the brand name Recarbrio[1][2].

Relebactam is designed to enhance the effectiveness of imipenem, which is a broad-spectrum antibiotic. By inhibiting certain enzymes (beta-lactamases) produced by bacteria, relebactam helps prevent bacteria from becoming resistant to imipenem. This makes the combination more effective against a wider range of bacterial infections, including some that are resistant to other antibiotics[3].

How Relebactam Works

Relebactam works by blocking enzymes called beta-lactamases that some bacteria produce. These enzymes can break down certain antibiotics, making them ineffective. By inhibiting these enzymes, relebactam allows imipenem to work more effectively against bacteria that would otherwise be resistant to it[4].

The combination of imipenem/cilastatin/relebactam is particularly effective against a group of bacteria known as Gram-negative bacteria. These include difficult-to-treat organisms like Pseudomonas aeruginosa and carbapenem-resistant Enterobacteriaceae (CRE), which are becoming increasingly resistant to many available antibiotics[3].

Conditions Treated with Relebactam

Imipenem/cilastatin/relebactam is approved to treat several types of serious bacterial infections, including:

  • Hospital-acquired bacterial pneumonia (HABP): This is a lung infection that develops during a hospital stay, usually after being on a ventilator[5].
  • Ventilator-associated bacterial pneumonia (VABP): This is a type of pneumonia that occurs in people who are on mechanical ventilation[5].
  • Complicated intra-abdominal infections (cIAI): These are serious infections that extend beyond the hollow organ of origin into the peritoneal space and are associated with abscess formation or peritonitis[1].
  • Complicated urinary tract infections (cUTI): These are urinary tract infections that have additional complications or occur in patients with functional or structural abnormalities of the urinary tract[6].

It’s important to note that this antibiotic combination is typically used for serious infections caused by bacteria that are resistant to other antibiotics. It’s not used for common infections or those caused by viruses[3][3].

How Relebactam is Administered

Imipenem/cilastatin/relebactam is given as an intravenous (IV) infusion, which means it’s administered directly into a vein. It’s typically given every 6 hours, and each dose is usually infused over 30 minutes[7].

The exact dosage depends on several factors, including the type and severity of the infection, the patient’s kidney function, and their body weight. For most adults with normal kidney function, the typical dose is 1.25 grams (which includes 500 mg imipenem, 500 mg cilastatin, and 250 mg relebactam) every 6 hours[7][8].

The duration of treatment can vary depending on the type and severity of the infection, but it’s usually given for at least 4 days and up to 14 days[5].

Clinical Studies and Effectiveness

Several clinical trials have been conducted to evaluate the effectiveness and safety of imipenem/cilastatin/relebactam:

  • A study compared imipenem/cilastatin/relebactam to piperacillin/tazobactam (another antibiotic combination) in patients with hospital-acquired and ventilator-associated bacterial pneumonia. The results showed that imipenem/cilastatin/relebactam was at least as effective as piperacillin/tazobactam in treating these serious infections[5].
  • Another study looked at the effectiveness of imipenem/cilastatin/relebactam in treating complicated intra-abdominal infections and complicated urinary tract infections. The results showed that it was effective in treating these infections, including those caused by some antibiotic-resistant bacteria[1][6].
  • A study is currently ongoing to evaluate the effectiveness of imipenem/cilastatin/relebactam in treating infections caused by carbapenem-resistant Enterobacteriaceae (CRE), which are particularly difficult-to-treat bacteria[3].

Use in Special Populations

Research is ongoing to understand how imipenem/cilastatin/relebactam can be used in special patient populations:

  • Patients with cystic fibrosis: A study is being conducted to determine the appropriate dosing and effectiveness of imipenem/cilastatin/relebactam in patients with cystic fibrosis, who often have different antibiotic needs due to the nature of their disease[9].
  • Critically ill patients on ECMO: Another study is looking at how the drug behaves in critically ill patients receiving extracorporeal membrane oxygenation (ECMO), a life support machine that oxygenates blood outside the body[10].
  • Obese patients in intensive care: Researchers are also studying how obesity affects the way the drug is processed in the body in critically ill patients[2].

Safety and Side Effects

Like all medications, imipenem/cilastatin/relebactam can cause side effects. Common side effects reported in clinical trials include:

  • Nausea and vomiting
  • Diarrhea
  • Headache
  • Elevated liver enzymes (which may indicate liver stress)

More serious but less common side effects can include allergic reactions, seizures, and a type of diarrhea caused by a bacteria called Clostridioides difficile[5][7].

It’s important to note that this medication is generally reserved for serious infections and should be used under close medical supervision. Your healthcare provider will monitor you for side effects and adjust the treatment as necessary[7].

Aspect Details
Drug Combination Relebactam + Imipenem/Cilastatin
Main Indications Studied Complicated urinary tract infections, complicated intra-abdominal infections, bacterial pneumonia, carbapenem-resistant infections
Administration Intravenous infusion, typically every 6 hours
Key Efficacy Measures Clinical response, microbiological response
Safety Assessments Adverse events, liver enzyme elevations, discontinuations due to adverse events
Pharmacokinetic Parameters Clearance, volume of distribution, area under the curve
Special Populations Critically ill patients, ECMO patients, obese patients, cystic fibrosis patients
Comparator Treatments Imipenem/cilastatin alone, other antibiotics like meropenem/vaborbactam, ceftazidime/avibactam

Ongoing Clinical Trials on Relebactam

  • Study on the Effectiveness and Safety of Cefepime/Nacubactam and Aztreonam/Nacubactam for Adults with Resistant Bacterial Infections

    Not recruiting

    3 1 1 1
    Croatia Czechia France Greece Latvia Slovakia +1
  • Study on Avibactam and Drug Combination for Treating Severe Infections in Patients

    Not recruiting

    3 1 1 1
    Investigated diseases:
    Greece
  • Study on the Effectiveness and Safety of Imipenem, Cilastatin, and XNW4107 for Adults with Hospital-Acquired or Ventilator-Associated Bacterial Pneumonia

    Not recruiting

    3 1 1 1
    Investigated diseases:
    France Spain

Glossary

  • Pharmacokinetics: The study of how a drug moves through the body, including how it is absorbed, distributed, metabolized, and eliminated.
  • Carbapenem-Resistant Enterobacteriaceae (CRE): A group of bacteria that are resistant to carbapenem antibiotics, which are often considered drugs of last resort for treating severe infections.
  • Complicated Urinary Tract Infection (cUTI): A urinary tract infection that is associated with factors that increase the risk of failing therapy, such as structural or functional urinary tract abnormalities.
  • Complicated Intra-Abdominal Infection (cIAI): An infection that extends beyond the hollow organ of origin into the peritoneal space, and is associated with abscess formation or peritonitis.
  • Extracorporeal Membrane Oxygenation (ECMO): A life support technique that provides both cardiac and respiratory support to patients whose heart and lungs are unable to function adequately.
  • Minimum Inhibitory Concentration (MIC): The lowest concentration of an antibiotic that prevents visible growth of a bacterium.
  • Area Under the Curve (AUC): A measure of the total exposure to a drug over time, used in pharmacokinetic studies.
  • Clearance: The volume of blood cleared of a drug per unit time, indicating how quickly a drug is eliminated from the body.
  • Volume of Distribution: A theoretical volume that a drug would have to occupy to provide the same concentration as is currently in the blood, used to understand how widely a drug is distributed in the body.
  • Adverse Event (AE): Any unfavorable and unintended sign, symptom, or disease temporarily associated with the use of a medical treatment or procedure.

References

  1. https://clinicaltrials.gov/study/NCT01506271
  2. https://clinicaltrials.gov/study/NCT05146154
  3. https://clinicaltrials.gov/study/NCT04785924
  4. https://clinicaltrials.gov/study/NCT04196608
  5. https://clinicaltrials.gov/study/NCT02493764
  6. https://clinicaltrials.gov/study/NCT01505634
  7. https://clinicaltrials.gov/study/NCT03293485
  8. https://clinicaltrials.gov/study/NCT04147221
  9. https://clinicaltrials.gov/study/NCT05561764
  10. https://clinicaltrials.gov/study/NCT04493151