Dosing Weights
Dosing: Adult Antimicrobial Dosing, Non-dialysis
For UCSF pharmacists, access the pharmacy guidance manual click here
Do not use high-dose extended interval dosing strategy (using Hartford nomogram) in the following populations:
- Cr Cl ≤ 20 ml/min - Aminoglycoside t ½ > 4.5 hours - Patients with burns > 20% total burn surface area (TBSA) | - Ascites - Cystic Fibrosis (CF) patients - Pregnancy (outside of surgical prophylaxis) - Spinal cord injury |
High-dose extended dosing strategy (Hartford nomogram):
| Indication | CrCl > = 60 mL/min | 40-59 mL/min | 21-39 mL/min | CrCl < = 20 mL/min | Comments |
|---|---|---|---|---|---|
| Cystitis | 5 mg/kg x 1 | 5 mg/kg x 1 | 5 mg/kg x 1 | Use conventional/traditional dosing | No nomogram or levels needed |
| Other infecions (exclude CF) | 7 mg/kg IV q24h | 7 mg/kg IV q 36h | 7 mg/kg IV q 48h | Use conventional/traditional dosing | Obtain 6-14 hour random gentamicin level after first dose to inform future dosing interval Consider consulting pharmacy to assist with suggested dosing and monitoring Use Harford dosing nomogram Do not use this dosing in CF patients |
Hartford dosing nomogram (gentamicin/tobramycin 7 mg/kg)
Urban Craig (5 mg/kg) dosing nomogram:
Conventional/traditional dosing:
Please consult pharmacy to help with dosing and monitoring plan. Below are suggested peak and trough goals based upon infection:
| Conventional/traditional dosing | ||
| Gentamicin/Tobramycin | ||
| Infection | Extrapolated Peak Goal | Extrapolated Trough Goal |
| Abdominal Infections (including peritonitis) | 6-8 | < 1 (0.5) |
| Bacteremia | 6-8 | < 1 (0.5) |
| Empiric therapy for Cystic Fibrosis (if cannot do high-dose extended interval dosing) | Extended interval preferred but if impaired renal function consider 8-12 for peak and < 1 (0.5) for trough | |
Endocarditis Gram positive (‘synergy in divided doses’) * Gram negative |
3-4 8-10 |
< 1 (0.5) < 1 (0.5) |
| Neutropenic Fever | 6-10 | < 1 (0.5) |
| Pneumonia | 8-10 | < 1 (0.5) |
Skin and soft tissue infections | 6-8 | < 1 (0.5) |
| Urinary tract infections (including pyelonephritis) | 4-6 | < 1 (0.5)
|
Cystic fibrosis (CF) patients:
Prior to choosing a dosing regimen the clinical pharmacist should review the patient’s previous aminoglycoside regimen(s) to determine if information from previous courses of therapy can aid n selecting dosing for a new course of treatment. Please contact pharmacy for assistance. If no history of previous doses and levels, then follow the below:
| Indication | CrCl > = 60 mL/min | 40-59 mL/min | 21-39 mL/min | CrCl < = 20 mL/min | Comments |
|---|---|---|---|---|---|
| CF exacerbation | 10 mg/kg IV q 24h | 10 mg/kg IV q 36h | 10 mg/kg IV q 48h | Use conventional/traditional dosing | Do not use Hartford nomogram With first dose, obtain two serum concentrations 2 hours and 6 hours (10 hours in impaired renal function, elderly), counting from the start of the infusion. This typically allows for 2 half-lives to pass between levels. Periodically, it may help to have a third level (trough) if needed for additional calculations. Consult pharmacy to assist. |
| Aminoglycoside for CF | Target peak | Target trough |
|---|---|---|
| Tobramycin | 20-35 mcg/mL* | < 1 mcg/mL |
*There may be instances (e.g., elevated MIC) where the targeted peak may need to go up to 40- 60 mcg/mL - contact adult ID pharmacist.
Dosing: Antimicrobial Dosing in Intermittent & Continuous Hemodialysis
| Indication | Intermittent Hemodialysis | Continuous Hemodialysis |
|---|---|---|
| All indications | Use conventional/traditional dosing Consult pharmacy to assist | Consult pharmacy to assist with dosing strategy |