Author: Brian Holtry

Erythromycin ethylsuccinate is administered orally. Erythromycin ethylsuccinate oral suspensions, chewable tablets, and film-coated tablets may be administered without regard to meals. Chewable tablets should not be swallowed whole. The fixed-combination preparation containing erythromycin ethylsuccinate and sulfisoxazole acetyl is administered orally and may be given without regard to meals.

Dosage of erythromycin estolate is expressed in terms of erythromycin. The usual adult oral dosage of erythromycin as the estolate is 250 mg every 6 hours. In severe infections, dosage may be increased to 4 g or more daily.

Chloramphenicol should be used only for the treatment of serious infections caused by susceptible bacteria or Rickettsia when potentially less toxic drugs are ineffective or contraindicated. The drug must not be used for the treatment of trivial infections, as a prophylactic agent to prevent bacterial infections, or when it is not indicated as in the treatment of colds, influenza, or throat infections.

The drug should not be used alone for empiric therapy in seriously ill patients if there is a possibility that the infection may be caused by gram-positive bacteria or if a mixed aerobic-anaerobic bacterial infection is suspected. In such infections, another anti-infective agent effective against the suspected, potentially aztreonam-resistant organism should initially be used concomitantly. Aztreonam has been used safely and effectively in conjunction with an aminoglycoside, clindamycin, erythromycin, metronidazole, a penicillin, or vancomycin.

Cefoxitin is used in the treatment of serious infections of the lower respiratory tract, skin and skin structure, bone and joint, and urinary tract; septicemia; gynecologic infections (including endometritis, pelvic cellulitis, and pelvic inflammatory disease); and intra-abdominal infections (including peritonitis and intra-abdominal abscess) caused by susceptible bacteria. Cefoxitin also has been used in the treatment of uncomplicated gonorrhea and is used for perioperative prophylaxis. Prior to and during cefoxitin therapy, the causative organism should be cultured and in vitro susceptibility tests conducted. In serious infections, therapy may be initiated pending results of in vitro tests.

Cefotetan should not be used in the treatment of meningitis or other CNS infections. Prior to initiation of cefotetan therapy, appropriate specimens should be obtained for identification of the causative organism and in vitro susceptibility tests. Cefotetan therapy may be started pending results of susceptibility tests, but should be discontinued if the organism is found to be resistant to the drug.

Imipenem and cilastatin sodium is a fixed combination of imipenem monohydrate (a semisynthetic carbapenem b-lactam antibiotic) and cilastatin sodium, 1, 35 which prevents renal metabolism of imipenem by dehydropeptidase I (DHP I).

Ertapenem is a synthetic carbapenem b-lactam antibiotic that is structurally and pharmacologically related to imipenem and meropenem. Like meropenem but unlike imipenem, ertapenem has a methyl group at position 1 of the 5-membered ring, which confers stability against hydrolysis by dehydropeptidase 1 (DHP 1) present on the brush border of proximal renal tubular cells, and therefore does not require concomitant administration with a DHP-1 inhibitor such as cilastatin. Ertapenem is almost completely absorbed following IM administration, having a mean bioavailability of 90%.