Pharmacotherapeutic group: Antibacterials for systemic use, carbapenems, ATC code: J01DH56
Mechanism of action
The bactericidal activity of imipenem results from the inhibition of penicillin binding proteins (PBPs) leading to inhibition of peptidoglycan cell wall synthesis.
Cilastatin limits the renal metabolism of imipenem and does not have antibacterial activity.
Relebactam is a non-beta lactam inhibitor of Ambler class A and class C beta-lactamases, including class A
Klebsiella pneumoniae
carbapenemase (KPC) and extended‑spectrum beta‑lactamases (ESBLs), and class C (AmpC-type) beta‑lactamases including Pseudomonas-Derived Cephalosporinase (PDC). Relebactam does not inhibit class B enzymes (metallo-beta-lactamases) or class D carbapenemases. Relebactam has no antibacterial activity.
Resistance
Mechanisms of resistance in Gram-negative bacteria that are known to affect imipenem/relebactam include the production of metallo-beta-lactamases or oxacillinases with carbapenemase activity.
Expression of certain alleles of the class A beta-lactamase Guiana extended-spectrum beta-lactamase (GES) and overexpression of PDC coupled with loss of imipenem entry porin OprD may confer resistance to imipenem/relebactam in
P. aeruginosa
. The expression of efflux pumps in
P. aeruginosa
does not affect activity of either imipenem or relebactam. Mechanisms of bacterial resistance that could decrease the antibacterial activity of imipenem/relebactam in Enterobacterales include porin mutations affecting outer membrane permeability.
Antibacterial activity in combination with other antibacterial agents
In vitro
studies have demonstrated no antagonism between imipenem/relebactam and amikacin, azithromycin, aztreonam, colistin, gentamicin, levofloxacin, linezolid, tigecycline, tobramycin, or vancomycin.
Susceptibility testing breakpoints
MIC (minimum inhibitory concentration) interpretive criteria for susceptibility testing have been established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) for imipenem-relebactam and are listed here: https://www.ema.europa.eu/documents/other/minimum-inhibitory-concentration-mic-breakpoints_en.xlsx.
Pharmacokinetic/pharmacodynamic relationship
Time that unbound plasma concentrations of imipenem exceed the imipenem/relebactam minimum inhibitory concentration (%
f
T > MIC) has been shown to best correlate with efficacy. The ratio of the 24 - hour unbound plasma relebactam AUC to imipenem/relebactam MIC (
f
AUC / MIC) has been determined to be the index that best predicts activity of relebactam.
Clinical efficacy against specific pathogens
Efficacy has been demonstrated in clinical studies against the pathogens listed under each indication that were susceptible to imipenem and relebactam
in vitro
:
Hospital-acquired pneumonia, including ventilator-associated pneumonia
Gram-negative micro-organisms
•
Escherichia coli
•
Haemophilus influenzae
•
Klebsiella pneumoniae
•
Pseudomonas aeruginosa
•
Serratia marcescens
In vitro
studies suggest that the following pathogens would be susceptible to imipenem and relebactam in the absence of acquired mechanisms of resistance:
Gram-negative aerobic micro-organisms
•
Acinetobacter calcoaceticus-baumannii
complex
•
Citrobacter
spp. (including
C. freundii
and
C. koseri
)
•
Enterobacter
spp. (including
E.
asburiae
and
E. cloacae)
•
Escherichia coli
•
Klebsiella
spp. (including
K. aerogenes, K. oxytoca
and
K. pneumoniae
)
•
Pseudomonas aeruginosa
•
Serratia marcescens
Gram-negative anaerobic micro-organisms
•
Bacteroides
spp. (including
B. fragilis
)
•
Fusobacterium
spp. (including
F. nucleatum
and
F. necrophorum
)
•
Prevotella
spp. (including
P.
melaninogenica, P. bivia,
and
P. buccae
)
Gram‑positive aerobic micro-organisms
•
Enterococcus faecalis
•
Staphylococcus aureus
(methicillin susceptible isolates only)
• Viridans group streptococci (including
S. anginosus
and
S. constellatus)
In vitro
studies indicate that the following species are not susceptible to imipenem and relebactam:
Gram-negative aerobic micro-organisms
•
Legionella
spp.
•
Stenotrophomonas
maltophilia
Paediatric population
The European Medicines Agency has deferred the obligation to submit the results of studies with Recarbrio in one or more subsets of the paediatric population in the treatment of Gram-negative bacterial infections (see section 4.2 for information on paediatric use).
⚠️ Warnings
Recarbrio is supplied as a dry powder in a single‑dose vial that must be constituted and further diluted using aseptic technique prior to intravenous infusion as outlined below:
• To prepare the infusion solution, contents of the vial must be transferred to 100 mL of an appropriate infusion solution (see sections 6.2 and 6.3): 9 mg/mL (0.9 %) sodium chloride. In exceptional circumstances where 9 mg/mL (0.9 %) sodium chloride cannot be used for clinical reasons 5 % glucose may be used instead.
• Withdraw 20 mL (10 mL times 2) of diluent from the appropriate infusion bag and constitute the vial with 10 mL of the diluent. The constituted suspension must not be administered by direct intravenous infusion.
• After constitution, shake vial well and transfer resulting suspension into the remaining 80 mL of the infusion bag.
• Add the additional 10 mL of infusion diluent to the vial and shake well to ensure complete transfer of vial contents; repeat transfer of the resulting suspension to the infusion solution before administering. Agitate the resulting mixture until clear.
• Constituted solutions of Recarbrio range from colorless to yellow. Variations of color within this range do not affect the potency of the product.
• For patients with renal insufficiency, a reduced dose of Recarbrio will be administered according to the patient's CrCl, as determined from Table 7. Prepare 100 mL of infusion solution as directed above. Select the volume (mL) of the final infusion solution needed for the appropriate dose of Recarbrio as shown in Table 7.
Parenteral medicinal products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Discard if discoloration or visible particles are observed.
Table 7: Preparation of Recarbrio doses
Creatinine Clearance (mL/min)
Dosage of Recarbrio (imipenem/cilastatin/relebactam) (mg)
Volume (mL) of Solution to be Removed and Discarded from Preparation
Volume (mL) of Final Infusion Solution Needed for Dosage
Greater than or equal to 90
500/500/250
N/A
100
Less than 90 to greater than or equal to 60
400/400/200
20
80
Less than 60 to greater than or equal to 30
300/300/150
40
60
Less than 30 to greater than or equal to 15 or ESRD on haemodialysis
200/200/100
60
40
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
Compatible medicinal products
The physical compatibility of Recarbrio with selected injectable medicinal products was evaluated in two commonly available diluents at a Y-infusion site. Compatible medicinal products with the corresponding compatible diluent (i.e., 5 % Dextrose Injection or 0.9 % Sodium chloride Injection) are listed below. Recarbrio should not be co‑administered through the same intravenous line (or cannula), with other medicinal products not listed below, as no compatibility data are available. Refer to the respective prescribing information of the co-administered medicinal product(s) to confirm compatibility of simultaneous co‑administration. This medicinal product must not be mixed with other medicinal products except those mentioned below.
List of Compatible Injectable Medicinal Products for use with 5 % Dextrose or 0.9 % Sodium chloride Injection as Diluents
• dexmedetomidine
• dopamine
• epinephrine
• fentanyl
• heparin
• midazolam
• norepinephrine
• phenylephrine
Compatible intravenous bags and infusion set materials
Recarbrio is compatible with the following intravenous container bags and infusion set materials. Any intravenous bags or infusion set materials not listed below should not be used.
Intravenous Container Bag Materials
Polyvinyl chloride (PVC) and polyolefin (polypropylene and polyethylene)
Intravenous Infusion Set Materials (with tubing)
PVC + Di‑(2-ethylhexyl)phthalate (DEHP) and polyethylene (PE)‑lined PVC
Incompatible medicinal products
Recarbrio for solution for infusion is physically incompatible with propofol in 5 % Dextrose (also named Glucose) or 0.9 % Sodium chloride.