Ertapenem Steriscience: Uses, Dosage & Side Effects

What Is Ertapenem Steriscience and What Is It Used For?

Ertapenem Steriscience contains the active substance ertapenem, which belongs to the carbapenem class of antibiotics. Carbapenems are beta-lactam antibiotics that are structurally related to penicillins and cephalosporins but possess a broader spectrum of antibacterial activity and greater stability against many bacterial resistance mechanisms. Ertapenem was developed to provide the clinical efficacy of a carbapenem with the convenience of once-daily dosing, making it particularly suitable for hospital use, outpatient parenteral antibiotic therapy (OPAT), and step-down treatment protocols.

Ertapenem exerts its bactericidal (bacteria-killing) effect by binding to penicillin-binding proteins (PBPs) within the bacterial cell wall. Specifically, ertapenem has high affinity for PBP 2, 3, 4, and 5 in Escherichia coli and PBP 1a, 2, 4, and 5 in Staphylococcus aureus. By inhibiting these enzymes, ertapenem blocks the final transpeptidation step of peptidoglycan biosynthesis, which is essential for maintaining the structural integrity of the bacterial cell wall. Without a functional cell wall, the bacterium undergoes osmotic lysis and dies. This mechanism is fundamentally similar to that of other beta-lactam antibiotics, but the carbapenem molecular structure confers exceptional stability against hydrolysis by most beta-lactamases, including the clinically important extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases.

The spectrum of activity of ertapenem encompasses a wide range of clinically relevant pathogens. It is active against many aerobic Gram-positive organisms (including methicillin-susceptible Staphylococcus aureus and Streptococcus pneumoniae), numerous aerobic Gram-negative organisms (including Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Haemophilus influenzae, and Moraxella catarrhalis), and many anaerobic bacteria (including Bacteroides fragilis, Clostridium species, and Peptostreptococcus species). This broad coverage against mixed aerobic-anaerobic flora makes ertapenem especially well-suited for treating polymicrobial infections such as complicated intra-abdominal infections and diabetic foot infections.

However, ertapenem has notable gaps in its spectrum that distinguish it from the broader carbapenems such as meropenem and imipenem. Ertapenem does not have clinically useful activity against Pseudomonas aeruginosa, Acinetobacter species, methicillin-resistant Staphylococcus aureus (MRSA), or Enterococcus species. This narrower spectrum compared to other carbapenems is actually considered an advantage in certain clinical scenarios, as it may exert less selective pressure for the emergence of carbapenem-resistant Pseudomonas and other multi-drug resistant organisms. Ertapenem is also susceptible to hydrolysis by metallo-beta-lactamases and certain serine carbapenemases (such as KPC enzymes), which are increasingly encountered in carbapenem-resistant Enterobacterales (CRE).

Ertapenem Steriscience is approved by the European Medicines Agency (EMA) and regulatory authorities in numerous countries for the following indications in adults and children aged 3 months and older:

• Complicated intra-abdominal infections: Including appendicitis complicated by perforation or abscess formation, peritonitis, biliary infections, and other polymicrobial abdominal infections typically involving a mix of Gram-negative aerobes and anaerobes.
• Community-acquired pneumonia: Moderate-to-severe cases requiring hospitalization and intravenous antibiotic therapy. Ertapenem provides excellent coverage against the most common causative pathogens including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and atypical pathogens (when used in combination with a macrolide).
• Complicated urinary tract infections: Including acute pyelonephritis (kidney infection) caused by susceptible organisms, particularly when ESBL-producing Enterobacterales are suspected or confirmed.
• Complicated skin and soft tissue infections: Including diabetic foot infections without osteomyelitis, where the infection involves deep soft tissues and/or is caused by polymicrobial flora. Clinical trials have demonstrated efficacy comparable to piperacillin/tazobactam in this setting.
• Acute gynaecological infections: Including post-partum endomyometritis, septic abortion, and post-surgical gynaecological infections, which are typically polymicrobial and involve both aerobic and anaerobic organisms.
• Prophylaxis of surgical site infection following elective colorectal surgery: Ertapenem is approved in adults for the prevention of wound infection and intra-abdominal abscess following planned colorectal procedures, administered as a single dose within 1 hour before surgical incision.

The once-daily dosing regimen of ertapenem is a significant practical advantage. Unlike meropenem and imipenem, which require multiple daily doses (typically every 6–8 hours), ertapenem achieves adequate pharmacokinetic exposure with a single daily infusion. This is due to its long plasma elimination half-life of approximately 4 hours and its very high plasma protein binding (approximately 92–95%), which creates a sustained free-drug concentration above the minimum inhibitory concentration (MIC) for susceptible organisms throughout the dosing interval. This property simplifies hospital workflows and makes ertapenem particularly suitable for outpatient parenteral antibiotic therapy (OPAT) programs, where patients receive intravenous antibiotics at home or in an ambulatory care setting.

What Should You Know Before Taking Ertapenem Steriscience?

Contraindications

Understanding the absolute contraindications for ertapenem is essential before treatment begins. Your doctor will assess these carefully before prescribing.

• Hypersensitivity to ertapenem or other carbapenems: Do not receive Ertapenem Steriscience if you have had an allergic reaction to ertapenem or any other carbapenem antibiotic (such as meropenem, imipenem, or doripenem). Allergic reactions can range from mild skin rashes to life-threatening anaphylaxis.
• Severe hypersensitivity to other beta-lactam antibiotics: If you have experienced a severe allergic reaction (anaphylaxis) to any penicillin or cephalosporin antibiotic, ertapenem should generally not be used due to the possibility of cross-reactivity between beta-lactam classes. The rate of cross-allergenicity between penicillins and carbapenems is estimated at approximately 1%, but in patients with a history of anaphylaxis, the risk is unacceptable.
• Hypersensitivity to excipients: Do not use if you are allergic to any of the other ingredients in the formulation, including lidocaine (if the intramuscular route is used) – patients with lidocaine allergy must receive the drug intravenously only.

Warnings and Precautions

Before and during treatment with Ertapenem Steriscience, inform your doctor if any of the following apply to you:

• Seizure disorders: If you have a history of epilepsy or other seizure disorders, your doctor will carefully weigh the benefits and risks. All carbapenems have the potential to lower the seizure threshold, and cases of seizures, myoclonus, and altered mental status have been reported during ertapenem treatment.
• Kidney impairment: If you have reduced kidney function, ertapenem may accumulate in your body because it is primarily eliminated by the kidneys. Patients on haemodialysis require a supplementary dose after each dialysis session. Your doctor will monitor kidney function throughout treatment.
• Liver impairment: While no dose adjustment is required for mild-to-moderate hepatic impairment, ertapenem has not been studied in patients with severe liver disease. Liver function tests may be monitored during treatment.
• Clostridioides difficile infection: Antibiotic-associated diarrhoea, including life-threatening pseudomembranous colitis caused by Clostridioides difficile (formerly Clostridium difficile), has been reported with virtually all antibiotics, including ertapenem. If you develop severe, persistent, or bloody diarrhoea during or after treatment, contact your doctor immediately. Do not take anti-diarrhoeal medications without medical advice.
• Superinfection: Prolonged use of any antibiotic may lead to overgrowth of non-susceptible organisms, including fungi (such as Candida). Your doctor will monitor for signs of superinfection and take appropriate action if needed.
• Infusion-related reactions: As with other intravenous medications, reactions at or near the infusion site (pain, swelling, redness) may occur. If you develop signs of phlebitis (inflammation of the vein), your infusion site may need to be changed.
• Antibacterial resistance: Ertapenem, like all antibiotics, should be used only when bacterial infection is proven or strongly suspected. Inappropriate use contributes to the development of antimicrobial resistance. Your doctor should base the choice of ertapenem on susceptibility testing results whenever possible.

Your doctor will perform regular assessments, including blood tests to monitor kidney function, liver function, and blood cell counts, throughout your treatment course.

Pregnancy and Breastfeeding

There are limited clinical data on the use of ertapenem in pregnant women. Animal reproductive toxicology studies have not demonstrated direct harmful effects at therapeutic doses; however, a decrease in fetal body weights and an increase in skeletal variations were observed at doses associated with maternal toxicity. Ertapenem should be used during pregnancy only if the potential clinical benefit justifies the potential risk to the fetus. Your doctor will carefully assess the severity of the infection and the availability of safer alternatives before prescribing ertapenem during pregnancy.

Ertapenem is excreted in human breast milk. Because of the potential for adverse effects in the breastfed infant (including diarrhoea, oral thrush, and disruption of gut flora), a decision should be made whether to discontinue breastfeeding or to discontinue the drug, taking into account the importance of the antibiotic treatment to the mother. If breastfeeding is continued during ertapenem treatment, the infant should be monitored for signs of gastrointestinal disturbance.

Driving and Operating Machinery

Ertapenem can cause dizziness, somnolence (drowsiness), and, rarely, hallucinations or altered mental status. If you experience any of these side effects, do not drive or operate machinery until the symptoms have fully resolved. This is particularly important during the first few days of treatment when the likelihood of CNS side effects may be highest.

Important Information About Ingredients

Each vial of Ertapenem Steriscience 1 g contains approximately 137 mg (approximately 6 mmol) of sodium. This is equivalent to approximately 6.9% of the WHO-recommended maximum daily dietary sodium intake for adults. Patients on a low-sodium diet or those receiving multiple daily doses of sodium-containing intravenous medications should be aware of this additional sodium load, as it may be clinically relevant in patients with heart failure, hypertension, or fluid overload.

How Does Ertapenem Steriscience Interact with Other Drugs?

Drug interactions with ertapenem are relatively limited compared to many other antibiotics, but several clinically significant interactions require careful attention. Ertapenem is not significantly metabolized by the cytochrome P450 enzyme system, and in vitro studies have shown that it does not inhibit the major CYP450 isoenzymes. However, certain pharmacokinetic and pharmacodynamic interactions are well-documented and can have serious clinical consequences.

Major Interactions

Minor Interactions

Ertapenem does not interact significantly with most commonly used medications. In clinical studies, ertapenem was safely co-administered with a wide range of drugs without significant pharmacokinetic alterations. However, as with all antibiotics, its effect on gut flora can indirectly influence the absorption or metabolism of orally administered drugs that depend on intestinal bacterial processes.

What Is the Correct Dosage of Ertapenem Steriscience?

Ertapenem Steriscience is always prepared and administered by a healthcare professional in a hospital or clinical setting. The powder must be reconstituted and diluted before intravenous administration. The dose and duration of treatment are determined by your doctor based on the type, severity, and location of your infection, as well as your kidney function and clinical response to therapy.

Adults (13 Years and Older)

Children (3 Months to 12 Years)

Elderly Patients

Renal Impairment and Haemodialysis

For patients with mild-to-moderate kidney impairment (creatinine clearance >30 mL/min), no dose adjustment is needed. For patients with severe renal impairment (creatinine clearance ≤30 mL/min) or those receiving haemodialysis, the recommended dose is 1 g once daily, but a supplementary dose of 150 mg is required following each haemodialysis session (if the daily dose was given within 6 hours before dialysis). This supplementary dose ensures that adequate drug levels are maintained, as ertapenem is partially removed by haemodialysis.

Missed Dose

Because Ertapenem Steriscience is administered by healthcare professionals in a controlled setting, missed doses are uncommon. If a dose is missed, it should be given as soon as possible. The next dose should then be administered at the next scheduled time. Do not double the dose to make up for a missed one.

Overdose

In clinical studies, inadvertent administration of up to 3 g of ertapenem per day did not result in clinically significant adverse effects. In the event of overdose, ertapenem should be discontinued and general supportive treatment given. Ertapenem can be removed by haemodialysis, but no specific information on the use of haemodialysis to treat overdosage is available. The most likely symptoms of significant overdose would be exaggerated known side effects, particularly nausea, diarrhoea, and CNS effects such as dizziness or seizures.

How Ertapenem Steriscience Is Given

Ertapenem Steriscience is supplied as a white to off-white powder in a glass vial. For intravenous administration, the powder is reconstituted with water for injection or sodium chloride 0.9% solution and then further diluted in sodium chloride 0.9% solution to a final volume suitable for infusion over 30 minutes. The reconstituted and diluted solution should be used within 6 hours at room temperature or within 24 hours if stored in a refrigerator (2–8°C). The solution must not be mixed with or physically added to solutions containing other medications. Glucose (dextrose) solutions must not be used as a diluent.

What Are the Side Effects of Ertapenem Steriscience?

Like all medicines, Ertapenem Steriscience can cause side effects, although not everyone gets them. The overall safety profile of ertapenem is well-established from extensive clinical trials involving over 2,000 adult patients and from post-marketing surveillance. The majority of reported side effects are mild to moderate in severity and self-limiting. Your medical team will monitor you throughout treatment and manage any side effects that arise.

CNS Side Effects

Central nervous system adverse reactions deserve special attention because they can be serious and may require treatment discontinuation. In clinical trials, seizures were reported in approximately 0.5% of patients receiving ertapenem. Risk factors for seizures include pre-existing CNS disorders (brain lesions, history of seizures), renal impairment (which leads to higher ertapenem levels), and advanced age. Other CNS effects such as headache, dizziness, and insomnia are more common but generally mild. Rarely, hallucinations, encephalopathy, and altered consciousness have been reported, primarily in elderly patients or those with impaired renal function.

Gastrointestinal Side Effects

Diarrhoea is the most commonly reported side effect and may range from mild, self-limiting loose stools to severe Clostridioides difficile-associated colitis. The disruption of normal gut flora by broad-spectrum antibiotics like ertapenem can allow C. difficile to proliferate and produce toxins that damage the intestinal lining. Symptoms of C. difficile infection include watery or bloody diarrhoea, abdominal cramping, and fever. This condition can occur during treatment or up to several weeks after the antibiotic has been stopped. If you develop severe diarrhoea during or after treatment, contact your doctor immediately.

How Should Ertapenem Steriscience Be Stored?

Keep this medicine out of the sight and reach of children. Do not use after the expiry date stated on the vial label and outer carton after EXP. The expiry date refers to the last day of that month.

• Unopened vials: Store below 25°C (77°F). Do not freeze.
• Reconstituted solution (before dilution): The reconstituted solution should be diluted in sodium chloride 0.9% immediately after preparation.
• Diluted solution (for infusion): Use within 6 hours at room temperature (up to 25°C), or store at 2°C to 8°C (refrigerator) and use within 24 hours. Once removed from the refrigerator, the diluted solution should be used within 6 hours. Do not re-freeze.
• Visual inspection: The reconstituted and diluted solution should be clear and colourless to pale yellow. Do not use if you observe particulate matter, cloudiness, or discolouration.
• Incompatibilities: Do not mix with glucose (dextrose)-containing solutions. Do not mix with or add to solutions containing other medications.

As Ertapenem Steriscience is prepared and administered in a hospital or clinic, storage will be handled by your healthcare team and pharmacy. Do not dispose of any medicines via wastewater or household waste. The healthcare professionals will ensure proper disposal of unused medicine to protect the environment.

What Does Ertapenem Steriscience Contain?

Active Substance

The active substance is ertapenem, present as ertapenem sodium. Each single-use vial contains ertapenem sodium equivalent to 1 g of ertapenem. After reconstitution with 10 mL of water for injection, each mL contains approximately 100 mg of ertapenem. The reconstituted concentrate must then be further diluted in sodium chloride 0.9% solution before intravenous infusion.

Ertapenem has the molecular formula C₂₂H₂₄N₃O₇SNa and a molecular weight of 497.50 g/mol (as the sodium salt). It is a synthetic 1-beta-methyl carbapenem that is structurally distinct from other carbapenems by having a benzoate group at the 2-position, which contributes to its high plasma protein binding and consequently its long half-life enabling once-daily dosing.

Inactive Ingredients (Excipients)

• Sodium hydroxide (E524) – used for pH adjustment to approximately 7.5

The formulation is notably simple, containing only the active substance and a pH adjuster. There are no preservatives, buffering agents, or other excipients in the formulation.

Appearance

Ertapenem Steriscience is a white to off-white lyophilized (freeze-dried) powder supplied in a Type I glass vial with a rubber stopper and aluminium flip-off cap. After reconstitution with water for injection, the solution is clear and colourless to pale yellow. Each package contains one or ten single-use vials.

Manufacturer

Ertapenem Steriscience is manufactured and marketed by Steriscience. The marketing authorisation applies to the European Union. Other brand names for ertapenem in other regions include Invanz (marketed by Merck & Co., Inc./MSD). The active substance and clinical profile are identical regardless of brand name.