ADJUNCTIVE ONCE-DAILY GENTAMICIN (3MG / KG) FOR INFECTIVE ENDOCARDITIS
| The European Society of Cardiology guidelines for the treatment of infective endocarditis have been updated with new dosage advice for the use of adjunctive gentamicin for Staphylococcal, Streptococcal and Enterococcal infective endocarditis. | ||
| Specimen |
Each blood culture sample should be drawn at intervals > 1 hr by separate venepuncture and not from an indwelling catheter If patient is acutely ill, take at least three sets of blood cultures within first 24 hr before commencement of antimicrobial therapy with at least one hour interval between each set. Do not delay antimicrobial therapy in acutely ill patients. If patient not acutely unwell take at least three sets of blood cultures and wait for results. If patient is injecting drug user, or has prosthetic heart valve or central venous catheter, consider fungal cultures. |
|
| Likely Organisms |
Staphylococcus spp Streptococcus spp Enterococcus spp |
|
| Treatment: |
In endocarditis the valve may be damaged at an early stage. In an ill patient do not wait for blood culture report or echocardiographic confirmation Gentamicin requires careful monitoring, especially in patients with renal impairment. Gentamicin carries an increased risk of ototoxicity and nephrotoxicity. Monitor for signs of deafness and balance problems which may occur at normal levels.
|
|
| Gentamicin 3mg/kg IV 24 hrly as a slow bolus over 5 minutes (see table below) in combination with an appropriate beta-lactam or glycopeptide antibiotic. Use lowest weight (see below). If there are concerns about nephrotoxicity, seek advice from Consultant Microbiologist/ID | Note: See Infective Endocarditis guideline for further information of antimicrobial regimes, including gentamicin, where appropriate. | |
| Duration | Discuss with microbiology / ID consultant. | |
- Weigh patient to obtain actual body weight.
- If unfit to be weighed or obese (i.e. 20% over IBW), use ideal body weight (see Ideal Body Weight (IBW) guideline).
- Use lowest weight (from actual or ideal body weight) to select gentamicin dose.
- Check patient is not currently receiving, nor has recently received, therapeutic gentamicin doses as this could lead to toxicity.
Table 1: Dose banding for gentamicin 3 mg/kg IV for adjunctive therapy in IE. Give as a slow bolus over 5 minutes.
| Weight (kg) | Dose of gentamicin (mg) |
|---|---|
| <43 | 120 |
| 43-50 | 140 |
| 51-57 | 160 |
| 58-63 | 180 |
| 64-70 | 200 |
| 71-77 | 220 |
| >77 | 240 |
| Serum Levels | Action |
|---|---|
| Pre dose (trough) level <1 mg/L |
Continue current regimen Re-check levels after a further 2-3 doses |
| Pre dose (trough) level ≥1mg/L | Repeat level check 12 hrly and omit further doses until pre dose (trough) level <1mg /L |
| Peak (one hour post-dose) levels do not require monitoring for this regime | |
Check iPortal for IC alert under patient alerts: if CARB present then discuss with microbiologist for empirical treatment