Meropenem Trihydrate

White or slight-yellow crystalline powder LOD ≤0.5% Heavy Metals ≤20 ppm

Meropenem trihydrate is a carbapenem antibiotic with wide spectrum of antibacterial. It is an ultra-broad spectrum beta-lactam antibiotic and has antibacterial activity against Gram-negative and Gram-positive bacteria as well as anaerobic microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Enterobacter species, Serratia marcescens, Streptococcus pyogenes, Streptococcus agalactiae and Citrobacter sp. Meropenem trihydrate is indicated for the treatment of serious bacterial infection including complicated skin infections, complicated intra-abdominal infections, urinary tract infections, severe pneumonia, broncho-pulmonary infections and bacterial meningitis.

Meropenem trihydrate is a thienamycin derivative antibacterial agent that is more stable to renal dehydropeptidase I than IMIPENEM, but does not need to be given with an enzyme inhibitor such as CILASTATIN. It is used in the treatment of bacterial infections, including infections in immunocompromised patients.
Meropenem trihydrate has also been used in the
antibiotic susceptibility testing of E coli isolates from harbor estuary sediment samples.
in the bacterial killing assay and for screening antibiotic resistance of cystic fibrosis patient′s sputum based Staphylococcus aureus transformed macrophages in phagocyte infection.
for screening Enterococcus faecalis from human bile.

The unique side chain at C-2 is associated with increased activity against Gram-negative bacteria, including H. influenzae. It is slightly less active than imipenem against Gram-positive organisms. It is active against anaerobes and more active against some strains that are less susceptible to imipenem. Its excellent activity against Gram-negative organisms is due to high affinity for multiple penicillin-binding proteins. Activity is little affected by inoculum size or the presence of serum. It is bactericidal at concentrations close to the MIC.
Stability to β-lactamases is similar to that of other carbapenems: it is highly resistant to most serine β-lactamases, including extended-spectrum enzymes, but can be hydrolyzed by metallo-β-lactamases and by serine carbapenemases.

Meropenem trihydrate (MRP) belongs to the carbapenem group of compounds. It is susceptible to degradation at high temperature and humidity. It is soluble in methanol-water or acetone-water combinations. It is used as an antibacterial agent for treating meningitis and pneumonia.

C_max 500 mg intravenous (30-min infusion): 23 mg/L end infusion
1 g intravenous (30-min infusion): 49 mg/L end infusion
Plasma half-life: 1 h
Volume of distribution: c. 0.3 L/kg
Plasma protein binding: 2%
Absorption and distribution
Meropenem is not absorbed after oral administration. It penetrates well into most body fluids and tissues, including CSF, achieving concentrations matching or exceeding those required to inhibit most susceptible bacteria. In pediatric patients (1 month to 15 years) with inflamed meninges it achieves CSF levels of 0.9–6.5 mg/L after a single intravenous infusion (40 mg/kg) over 30 min. After a single intravenous dose, the highest mean concentrations of meropenem were found in tissues and fluids at 1 h (0.5–1.5 h) after the start of infusion.
Metabolism and excretion
The mean recovery of unchanged meropenem is approximately 70%. The remainder consists of the microbiologically inactive open-ring form. Renal excretion is greater than 70% of unchanged drug over 12 h. Co-administration with probenecid prolongs the half-life 38%, but peak concentrations are not greatly affected. In patients with renal impairment the dose should be adjusted. Parent drug and metabolite are removed by hemodialysis.

Meropenem is a second-generation carbapenem that, todate, has undergone the most extensive clinical evaluation.It has recently been approved as Merrem for the treatmentof infections caused by multiply-resistant bacteria and forempirical therapy for serious infections, such as bacterialmeningitis, septicemia, pneumonia, and peritonitis.Meropenem exhibits greater potency against Gram-negativeand anaerobic bacteria than does imipenem, but it is slightlyless active against most Gram-positive species. It is not effectiveagainst MRSA. Meropenem is not hydrolyzed byDHP-I and is resistant to most β-lactamases, including a fewcarbapenemases that hydrolyze carbapenem.

Intra-abdominal infections
Bacterial meningitis (pediatric patients >3 months)
Complicated skin and skin structure infections

Seizures and other CNS adverse experiences have been reported in 0.7% of all adult patients, most commonly those with pre-existing CNS disorders. Pseudomembranous colitis has been reported. Other reactions include diarrhea (4.8%), nausea and vomiting (3.6%), inflammation at the site of injection (2.4%) and headache (2.3%). Moniliasis occurs in 1.9–3.1% of pediatric patients.
Patients with a history of hypersensitivity reactions to other β-lactam agents should be treated cautiously.