Imipenem - beta-laktam antibiotik keng spektrli ta'sir ko'rsatuvchi vosita bo'lib, tienamitsinning hosilasi hisoblanadi va karbapenemlar guruhiga kiradi. Bakteriyalarning hujayra devorining sintezini bostiradi va keng spektrdagi gram-musbat va gram-manfiy aerob hamda anaerob mikroorganizmlarga qarshi bakteritsid ta'sir ko'rsatadi. Tsilastatin natriy - bu imipenemni buyraklarda metabolizatsiya qiluvchi dehidropeptidaza fermentini inhibe qiluvchi moddadir, bu esa siydik yo'llaridagi o'zgarmagan imipenemning kontsentratsiyasini sezilarli darajada oshiradi. Tsilastatin o'zining antibakterial faolligi yo'q, bakteriyalarning beta-laktamazalarini bostirmaydi.
Grimipenem bakterial beta-laktamazalarga chidamlidir, bu uni beta-laktamaz ishlab chiqaruvchi ko'pchilik mikroorganizmlarga, masalan, Pseudomonas aerugenosa, Serratia spp. va Enterobacter spp. kabi penitsillin va tsefalosporinlarga chidamli turlarga qarshi samarali qiladi.
Grimipenem quyidagi mikroorganizmlarga qarshi faol:
Gram-manfiy aerob bakteriyalar: Achromobacter spp., Acinetobacter spp., Aeromonas hydrophila, Alcaligenes spp., Bordetella bronchicanis, Bordetella bronchiseptica, Bordetella pertussis, Brucella melitensis, Campylobacter spp., Capnocytophaga spp., Citrobacter spp., Citrobacter diversus, Citrobacter freundii, Eikenella corrodens, Enterobacter spp., Enterobacter aerogenes, Enterobacter agglomerans, Enterobacter cloacae, Escherichia coli, Gardnerella vaginalis, Haemophilus ducreyi, Haemophilus influenzae (beta-laktamaza ishlab chiqaruvchi shtramlarni o'z ichiga olgan), Haemophilus parainfluenzae, Hafnia alvei, Klebsiella spp. (Klebsiella oxytoca, Klebsiella ozaenae, Klebsiella pneumoniae), Moraxella spp., Morganella morganii, Neisseria gonorrhoeae (beta-laktamaza ishlab chiqaruvchi shtramlarni o'z ichiga olgan), Neisseria meningitidis, Pasteurella spp., Pasteurella multocida, Plesiomonas shigelloides, Proteus spp., Proteus mirabilis, Proteus vulgaris, Providencia spp., Providencia alcalifaciens, Providencia rettgeri, Providencia stuartii, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas pseudomallei, Pseudomonas putida, Pseudomonas stutzeri, Salmonella spp., jumladan Salmonella typhi, Serratia spp. (Serratia proteamaculans, Serratia marcescens), Shigella spp., Yersinia spp., Yersinia enterocolitica, Yersinia pseudotuberculosis;
Gram-musbat aerob bakteriyalar: Bacillus spp., Enterococcus faecalis, Erysipelothrix rhusiopathiae, Listeria monocytogenes, Nocardia spp., Pediococcus spp., Staphylococcus aureus (penitsillinaza ishlab chiqaruvchi shtramlarni o'z ichiga olgan), Staphylococcus epidermidis (penitsillinaza ishlab chiqaruvchi shtramlarni o'z ichiga olgan), Staphylococcus saprophyticus, Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, yashil rangli streptokokklar, jumladan alfa- va gamma-gemolitik shtramlar, C va G guruhi streptokokklar;
Gram-manfiy anaerob bakteriyalar: Bacteroides fragilis, Bacteroides spp. (Bacteroides distasonis, Bacteroides ovatus, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus), Bilophila wadsworthia, Fusobacterium spp. (Fusobacterium necrophorum, Fusobacterium nucleatum), Porphyromonas asaccharolytica, Prevotella bivia, Prevotella disiens, Prevotella intermedia, Prevotella melaninogenica, Veillonella spp.;
Gram-musbat anaerob bakteriyalar: Actinomyces spp., Bifidobacterium spp., Clostridium spp. (Clostridium perfringens), Eubacterium spp., Lactobacillus spp., Mobiluncus spp., mikroaerofil streptokokklar, Peptococcus spp., Peptostreptococcus spp., Propionibacterium spp. (Propionibacterium acnes);
Boshqa mikroorganizmlar: Mycobacterium fortuitum, Mycobacterium smegmatis.
In vitro sharoitida ba'zi Pseudomonas aeruginosa shtramlari bilan aminoglikozidlar bilan sinergid ta'sir ko'rsatadi. Metitsillin chidamli Staphylococcus spp. shtramlari, Stenotrophomonas maltophilia, Enterococcus faecium va ayrim Burkholderia cepacia shtramlari Grimipenemga sezgir emas.