Antibiotic Prophylaxis in Surgery - Drug Dosing, Administration and Redosing

ANTIBIOTIC

DOSE

ADMINISTRATION

REDOSE IN PROLONGED PROCEDURE

REDOSE AFTER >1.5L BLOOD LOSS - (REDOSE AFTER FLUID REPLACEMENT)

Amoxicillin

1g IV

Bolus over 3-4 minutes

After 4 hours: 1g IV

After 8 hours: 1g IV

1g IV 

Cefuroxime 1.5g IV Bolus over 3-4 minutes After 4 hours: 1.5g IV 

After 8 hours: 1.5g IV 

1.5g IV 
Ciprofloxacin 1000mg PO 1hr pre-procedure N/A N/A
Co-amoxiclav 1.2g IV Bolus over 3-4 minutes

After 4 hours: 1.2g IV 

After 8 hours: 1.2g IV 

1.2g IV
Clindamycin 600mg IV Infuse over 10-60 mins

After 4 hours: 600mg IV

After 8 hours: 600mg IV 

600mg IV 
Flucloxacillin 1g IV Bolus over 3-4 minutes

After 4 hours: 1g IV dose

After 8 hours: 1g IV dose

1g IV 

Gentamicin

 

3mg/kg IV

Use ideal body weight (IBW) if >20% overweight - see below

 

Do not repeat dose unless >1.5L blood loss or surgery > 8 hours (half dose)

 

Bolus over 2-3 minutes. Can also be given as short infusion

 

After 4 hours: NOT REQUIRED

After 8 hours: Half original pre-op dose if no renal impairment (i.e. CrCl > 60mL/min)

 

 

Half original pre-op dose

Metronidazole 500mg IV Infuse over 20 minutes

After 4 hours: NOT REQUIRED

After 8 hours: 500mg IV 

500mg IV 
Teicoplanin

<65kg:         400mg

66-99kg:      600mg

100-130kg:  800mg

131-166kg:  1000mg

Infuse over 3-4 minutes

After 4 hours: NOT REQUIRED

After 8 hours: NOT REQUIRED

Half original pre-op dose if ≥ 1.5 litre blood loss occurs in 1st hour of procedure

*IBW= Male: 50kg / Female 45.5kg +0.9kg for every cm>150cm

WEIGHT-BASED DOSING:

  Weight >100kg
Co-Amoxiclav

Add Amoxicillin 1g IV to Co-amoxiclav 1.2g IV

(i.e. total dose = 2g Amoxicillin and 200mg clavulanic acid) 

NB:-

Redosing antibiotics for surgical prophylaxis to maintain antibiotic concentrations during prolonged surgical
procedures can significantly reduce the rate of surgical site infections (SSI).

For procedures lasting more than 4 hours, redosing (where indicated) after 4 or 8 hours promotes safe and
effective surgical prophylaxis. Decisions around redosing should be made on an individual patient basis
taking account of the risks and benefits of repeat dosing. Patients with complex management requirements
should be discussed with microbiology colleagues in advance to ensure redosing is safe and appropriate.
These recommendations include redosing advice where there is intraoperative blood loss of 1,500 mL or
more.

It is not recommended to give a repeat dose of antibiotics after every subsequent 1,500 mL blood
loss and specialist advice is needed where blood loss exceeds 3,000 mL.

(Reference: Good practice recommendations for redosing antibiotics for surgical prophylaxis in adults Oct 22)