Meropenem, sold under the brand name Merrem among others, is an intravenous carbapenem antibiotic used to treat a variety of bacterial infections.

[3] Common side effects include nausea, diarrhea, constipation, headache, rash, and pain at the site of injection.

This mechanism helps bacteria resist the effects of antibiotics like penicillins, cephalosporins, and carbapenems, making treatment more challenging.

[19] In 2017, the U.S. Food and Drug Administration (FDA) granted approval for the combination of meropenem and vaborbactam to treat adults with complicated urinary tract infections.

[32] Upon reconstitution, the meropenem infusion solution, prepared with 0.9% sodium chloride, exhibits both chemical and physical stability for a duration of 3 hours at a temperature up to 25°C.

[40] This means that while meropenem is designed to resist bacterial enzymes, it can still be broken down by water, which is a bit ironic.

[41] That's why meropenem requires frequent or prolonged slow administration to supply new drug to the bloodstream to replace what was hydrolyzed by the water component of blood.

[47][48] Meropenem exhibits poor permeability across the gut and low oral bioavailability because of its hydrophilic properties, which inhibit its passive diffusion across the intestinal epithelium.

Besides that, meropenem is unstable in the acidic environment of the stomach, leading to extensive degradation and loss of the drug after oral administration.

Nonetheless, there have been sporadic reports of disturbances in the gastrointestinal flora of the infant, manifesting as diarrhea or oral candidiasis (thrush), associated with the use of β-lactam antibiotics, however, these potential side effects have not been thoroughly investigated specifically in the context of meropenem use, therefore, the safety profile of meropenem in breastfeeding mothers and their infants is unknown.

[52] There was also a small study on local tolerance of meropenem intramuscular administration in humans, and it was reported as generally good.

[4][46] The most common adverse effects are diarrhea (4.8%), nausea and vomiting (3.6%), injection-site inflammation (2.4%), headache (2.3%), rash (1.9%) and thrombophlebitis (0.9%).

[55] Many of these adverse effects were observed in severely ill individuals already taking many medications including vancomycin.

[61] In 2016, a synthetic peptide-conjugated PMO (PPMO) was found to inhibit the expression of New Delhi metallo-beta-lactamase 1, an enzyme that many drug-resistant bacteria use to destroy carbapenems.