Prophylaxis for repair of obstetric anal sphincter injuries
Give a single preprocedural dose of antibiotic(s) before the repair of an obstetric anal sphincter injury (OASIS) (including third- or fourth-degree perineal tears). Use:
cefazolin 2 g intravenously, as early as possible; redosing may be required (see Duration of surgical antibiotic prophylaxis). Do not give additional intravenous doses once the procedure is completed cefazolin cefazolin
PLUS
metronidazole 500 mg intravenously, as early as possible; redosing may be required (see Duration of surgical antibiotic prophylaxis). Do not give additional intravenous doses once the procedure is completed. metronidazole metronidazole
As an alternative, cefoxitin may be used as a single drug; however, its activity against anaerobes is inferior to the regimen above and it requires frequent redosing (every 2 hours). Use:
cefoxitin 2 g intravenously, as early as possible; redosing may be required (see Duration of surgical antibiotic prophylaxis). Do not give additional intravenous doses once the procedure is completed. cefoxitin cefoxitin
For patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use either of the regimens above.
For patients who have had a severe immediate1 hypersensitivity reaction to a penicillin, cefazolin or cefoxitin (at the dosage above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).
For patients who have had a severe immediate1 hypersensitivity reaction to a penicillin in whom cefazolin or cefoxitin is not used, or for patients who have had a severe delayed2 hypersensitivity reaction to a penicillin, use:
clindamycin 600 mg intravenously, as early as possible; redosing may be required (see Duration of surgical antibiotic prophylaxis). Do not give additional intravenous doses once the procedure is completed. clindamycin clindamycin
The role of postoperative antibiotic therapy following anal sphincter repair is unclear, but is recommended because infection in this setting carries a high risk of anal incontinence and fistula formation. Use:
amoxicillin+clavulanate 875+125 mg orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate oral dosage adjustment. amoxicillin + clavulanic acid amoxicillin+clavulanate
For patients who have had a nonsevere (immediate or delayed) penicillin hypersensitivity or severe immediate1 penicillin hypersensitivity who tolerated cefazolin or cefoxitin, cefalexin can be used3; however, cefalexin must not be used if the patient has had a severe (immediate or delayed)4 hypersensitivity reaction to amoxicillin or ampicillin. If cefalexin is appropriate, use:
cefalexin 500 mg orally, 6-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see cefalexin dosage adjustment cefalexin cefalexin
PLUS
metronidazole 400 mg orally, 12-hourly for 5 days metronidazole metronidazole.
For patients with severe immediate1 penicillin hypersensitivity in whom cefazolin or cefoxitin was not used nor tolerated, or for patients with severe delayed2 penicillin hypersensitivity, use:
trimethoprim+sulfamethoxazole 160+800 mg orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustmenttrimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole
PLUS
metronidazole 400 mg orally, 12-hourly for 5 days.metronidazole metronidazole