Surgical Antibiotic Prophylaxis Dose and Redose Clock
The preoperative antibiotic dose by weight and when to redose it, from Table 1 of the 2013 ASHP/IDSA/SIS/SHEA guideline.
Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Antimicrobial
- Cefazolin
- Adult or child
- Adult
- Actual weight
- 85 kg
- Preoperative dose started
- 2026-10-18T07:30
- Incision time
- 2026-10-18T07:55
Result: Cefazolin (adult): 2 g; redose every 4 hours from the start of the dose.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Antimicrobial
- Adult or child
- Actual weight
- Ideal body weight (gentamicin only)
- Age band (piperacillin-tazobactam in a child)
- Preoperative dose started (YYYY-MM-DDTHH:MM)
- Incision time (YYYY-MM-DDTHH:MM)
How this is calculated
Citation
Bratzler DW et al. Clinical practice guidelines for antimicrobial prophylaxis in surgery. Am J Health Syst Pharm. 2013;70:195-283, Table 1 and the timing recommendation. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.