Meropenem is an antibiotic that belongs to the group of carbapenems. The drug is used primarily in the context of the therapy of bacterial infections. Among other things, the fact that meropenem is effective against both gram-negative and gram-positive germs and bacteria is exploited. In the majority of cases, the drug is administered by intravenous injection.
What is meropenem?
Meropenem is primarily used in the treatment of bacterial infections and is administered by injection or infusion solutions. The drug meropenem is one of the so-called carbapenems. This group of active substances includes drugs such as cephalosporins, penicillins and the monobactams. These substances are betalactam antibiotics. Of all the beta-lactam antibiotics, the carbapenems have the broadest spectrum of activity. In addition, these substances also have the strongest broad-spectrum effect with regard to bacterially caused infectious diseases. The only exceptions are Enterococcus faecium and methicillin-resistant Stenotrophomonas maltophilia and staphylococci, which in many cases cause serious infections. The active ingredient meropenem is also used in antibacterial chemotherapy in combination with the drug imipenem or cilastatin. Here it represents the second carbapenem derivative used for this purpose. In principle, meropenem is a derivative of the substance thienamycin, which makes it similar to imipenem. However, the latter has not been sufficiently developed to be sold on the pharmacological market. The shelf life of the active ingredient in a solution depends primarily on the solvent and also varies depending on the room temperature. Here, the shelf life ranges from two to eight hours when it has been dissolved in a ten percent glucose solution. In pharmacological use, meropenem occurs as a trihydrate. This is a whitish to yellowish powder of crystalline appearance. In water, the substance is virtually insoluble.
Pharmacological action
The mechanism of action of the drug meropenem is largely understood. The substance acts similarly to other beta-lactam antibiotics by restricting the synthesis of bacterial cell walls. As a result, the drug exerts a bactericidal effect. With regard to Listeria monocytogenes, meropenem exhibits a primarily bacteriostatic effect. In principle, the active ingredient shows high stability against beta-lactamases of a bacterial nature. The bactericidal effects of meropenem are mainly due to the impairment of the synthesis of cell walls. As a broad-spectrum antibiotic, meropenem is characterized by a wide spectrum of activity. In some cases, it is even called an ultra-broad spectrum antibiotic. Meropenem is effective against anaerobic and aerobic as well as gram-positive and gram-negative germs. The spectrum of action of meropenem is similar to that of imipenem. However, meropenem is more effective against enterobacteria, whereas it is less effective against Gram-positive germs. In some cases, resistance to meropenem is possible and can develop in a variety of ways. For example, the proteins of the germs that bind penicillin can change. This occurs, for example, with certain bacterial strains from the Enterococcus faecium group. Corresponding mechanisms are particularly evident with Gram-negative pathogens, such as Pseudomonas strains. As a result, the cell membrane of the bacteria is affected. The antibiotic is no longer able to accumulate sufficiently in the germ. The drug is primarily excreted renally. In this process, the concentration within the cerebrospinal fluid is relatively low, but in the case of meningitis it is greatly increased. The half-life of the drug is approximately one hour.
Medical application and use
Meropenem is a so-called reserve antibiotic. Thus, it is used to treat life-threatening infectious diseases and mixed infections caused by meropenem-sensitive germs. Possible areas of use include serious infections of the respiratory and urinary tracts. Meropenem can also be used in the context of sepsis. The drug is approved for the treatment of serious infections in adults and children older than three months.For this reason, the possible scope of application of meropenem ranges from nosocomial pneumonia, meningitis and intra-abdominal infectious diseases to serious gynecological infections. Meropenem can also be used in the treatment of infections of the kidney, urinary tract, soft tissues and skin. The drug can also be used in cystic fibrosis and to control febrile episodes in neutropenic adults when bacterial pathogens are suspected. Because meropenem is predominantly stable against so-called renal dehydropeptidase I, it does not need to be taken in combination with an inhibitory agent of the corresponding enzyme, such as cilastatin. The active ingredient meropenem is available in the form of a powder that is used to produce injection or infusion solutions.
Risks and side effects
Basically, the possible undesirable side effects of the drug meropenem are similar to those of other beta-lactam antibiotics, especially those of the active ingredient imipenem. One difference here is particularly with regard to the greatly reduced neurotoxicity. Common side effects include in particular local skin reactions at the site of injection, for example in the form of pain or inflammation, itching or rash. In addition, headache and nausea, diarrhea and vomiting are possible. Occasionally, thrombocythemia occurs. In some cases, epileptic seizures occur after taking meropenem.
