Meropenem and Azithromycin Dosage and Duration Recommendations

Meropenem Dosing

The World Journal of Emergency Surgery recommends meropenem 1 gram IV every 8 hours for intra-abdominal infections in adults with normal renal function 1
Extended infusion over 3 hours may be considered if treating resistant organisms with MIC ≥ 8 mg/L 2

The World Journal of Emergency Surgery and the Journal of Microbiology, Immunology and Infection recommend 5-7 days as the duration of therapy for complicated intra-abdominal infections 1, 2
Treatment duration should be individualized based on infection severity, source control, and clinical response 2

The MMWR Recommendations and Reports recommend azithromycin 500 mg on day 1, followed by 250 mg per day on days 2-5 for adults 3
The total treatment course for azithromycin is 5 days 3
Azithromycin should not be taken simultaneously with aluminum- or magnesium-containing antacids as they reduce absorption 3
Use with caution in patients with impaired hepatic function 3
Monitor patients when azithromycin is used with drugs metabolized by the cytochrome P450 enzyme system 3

For carbapenem-resistant Enterobacterales causing intra-abdominal infections, alternative regimens may include ceftazidime/avibactam plus metronidazole or tigecycline 2, 4
Extended-infusion of meropenem (over 3 hours) is suggested for organisms with elevated MICs 2

For post-operative intra-abdominal infections, the American College of Surgeons recommends a dosage of 1 gram IV every 8 hours as an infusion over 15-30 minutes, with a strength of evidence based on clinical guidelines 5

For patients with colonization of extended-spectrum cephalosporin-resistant Enterobacterales (ESCR-E), the Infectious Diseases Society of America suggests avoiding carbapenems if alternatives are available, and ertapenem is preferred over meropenem for prophylaxis due to single-dose administration and antimicrobial stewardship considerations 6
The European Society of Clinical Microbiology and Infectious Diseases recommends a post-operative dosage of meropenem every 6-8 hours if used 6