Adult Weight-Based Antimicrobial Dosing Protocol
Legacy Health Modified from original work by Lindsie M. Froehlich, PharmDADULT WEIGHT-BASED ANTImicROBIAL DOSAGE ADJUSTMENT TABLE | |||||||
WEIGHT (kg) |
CrCl > 50 |
CrCl 30 – 50 |
CrCl 10 – 30 |
CrCl <10 |
|||
PENICILLINS |
|||||||
<80 |
1gm q6hb |
1gm q8 |
1gm q12h |
1gm q24h |
|||
80-139 |
2gm q6ha |
2gm q8h |
2gm q12h |
2gm q24h |
|||
>140 |
3gm q6ha |
3gm q8h |
3gm q12h |
3gm q24h |
|||
< 100 |
2gm q4h |
No dosage adjustment necessary |
|||||
>100 |
3gm q4h |
||||||
< 100 |
3mU q4h |
2mU q4h |
2mU q8h |
1mU q8h |
|||
>100 |
4mU q4h |
3mU q4h |
3mU q8h |
2mU q8h |
|||
< 80 |
1.5gm q6h |
1.5gm q8h |
1.5gm q12h |
1.5gm q24h |
|||
80 – 139 |
3gm q6h |
3gm q8h |
3gm q12h |
3gm q24h |
|||
>140 |
4.5gm q6h |
4.5gm q8h |
4.5gm q12h |
4.5gm q24h |
|||
CrCl >40 |
CrCl 20 – 40 |
CrCl <20 |
|||||
< 100 PSE |
3.375gm q6 |
2.25gm q6h* |
2.25gm q8h* |
||||
4.5gm q6h |
3.375gm q6h* |
2.25gm q6h* |
|||||
100 - 139 PSE |
3.375gm q4h |
2.25gm q4h* |
2.25gm q6h* |
||||
4.5gm q4h |
3.375gm q4h* |
2.25gm q4h* |
|||||
>140 PSE |
4.5gm q6h |
3.375gm q6h* |
2.25gm q6h* |
||||
6gm q6h |
4.5gm q8h* |
3.375gm q8h* |
|||||
CEPHALOSPORINS |
|||||||
< 80 |
1gm q8h |
500mg q12h* |
500mg q24h* |
||||
80 – 149 |
2gm q8h |
1gm q12h* |
1gm q24h* |
||||
>150 |
3gm q8h |
2gm q12h* |
2gm q24h* |
||||
< 80 |
1gm q8h |
1gm q12h |
1gm q24h |
500mg q24h* |
|||
80 – 149 |
2gm q8h |
2gm q12h |
2gm q24h |
1gm q24h* |
|||
>150 |
3gm q8h |
3gm q12h |
3gm q24h |
1gm q24h* |
|||
< 80 |
1gm q24h |
No dosage adjustment necessary |
|||||
80 - 129 |
2gm q24h |
||||||
>130 |
3gm q24h |
||||||
< 80 |
1gm q12h |
Same dose |
1gm IV q24h |
1gm q48h |
|||
81 – 139 |
2gm q12h |
Same dose |
2gm q24h |
2gm q48h |
|||
>140 |
3gm q12h |
Same dose |
3gm q24h |
3gm q48h |
|||
< 100 |
1gm q8h |
1gm q12h |
1gm q24h |
500mg q24h* |
|||
>100 |
2gm q8h |
2gm q12h |
2gm q24h |
1gm q24h* |
|||
CARBAPENEMS |
|||||||
< 100 |
1gm q24h |
Same dose |
500mg q24h* |
Same dose* |
|||
>100 |
2gm q24h |
Same dose |
1gm q24h* |
500mg q24h* |
|||
< 100 |
1gm q8h |
1gm q12h |
500mg q12h* |
500mg q24h* |
|||
>100 |
2gm q8h |
2gm q12h |
1gm q12h* |
1gm q24h* |
|||
FLUOROQUINOLONES |
|||||||
< 100 |
400mg q12h |
400mg q24h |
200mg q24h* |
||||
101 - 139 |
600mg q12h |
600mg q24h |
300mg q24h* |
||||
>140 |
800mg q12h |
800mg q24h |
400mg q24h* |
||||
< 100 |
400mg q24h |
No dosage adjustment necessary |
|||||
101 – 139 |
600mg q24h |
||||||
>140 |
800mg q24h |
||||||
>150 |
750mg q24h |
||||||
WEIGHT (kg) |
CrCl > 50 |
CrCl 30 – 50 |
CrCl 10 – 30 |
CrCl <10 |
|||
MISCELLANEOUS |
|||||||
< 80 |
1gm q6h |
500mg q6h* |
250mg q6h* |
||||
>80 |
2gm q6h |
1gm q6h* |
500mg q6h* |
||||
< 80 |
600mg q8h |
No dosage adjustment necessary |
|||||
>80 |
900mg q8h |
||||||
Use TBW |
4-6 mg/kg q24h |
q48h |
|||||
<80 |
400mg q24h |
200mg q24h* |
|||||
80 - 149 |
800mg q24h |
400mg q24h* |
|||||
>150 |
1200mg q24h |
600mg q24h* |
|||||
< 150 |
600mg q12h |
No dosage adjustment necessary |
|||||
>150 |
600mg q8h |
||||||
a
Use same
dose q4h for endocarditis and meningitis
b
Use 2 gm q4h forendocarditis and meningitis PSE
= Pseudomonas infection (excluding urinary tract infection TBW:
Total body weight (kg)
1. Empiric dosing should be based off of an
adjusted body weight calculation using a correction factor of 40% ABW
= (TBW – IBW) x 0.4 + IBW 2. Use normal empiric dosing intervals
based on renal function. 3. DO NOT use extended interval dosing in
the obese population. 4. Follow peak and trough levels and
adjust dose accordingly. B. Vancomycin 1. Patients should receive an initial loading dose
of 15 mg/kg based on total body weight. Maximum single dose = 3gm 2. Empiric dosing should be continued using total
body weight for a total daily dose of 20 – 30 mg/kg/day with a single dose cap of 3gm. 3. Vancomycin is a time dependent antibiotic, so
shorten administration interval to q6h in patients with normal renal function
if necessary to maintain serum trough >10. 4. Check trough levels regularly and adjust dose
accordingly, see LHS protocol for specific trough recommendations Obesity Dosing
Quick Reference Sheet Drug IBW TBW DW Comments x No need to adjust fixed doses for obese patients x DW = 0.4 (TBW – IBW) + IBW x TBW for both conventional and liposomal x x No need to adjust fixed doses for obese patients x DW = 0.45 (TBW – IBW) + IBW x x x x x x DW = 0.4 (TBW – IBW) + IBW x No need to adjust fixed doses for obese patients x x x x No need to adjust fixed doses for obese patients x DW = 0.4 (TBW – IBW) + IBW x DW = 0.4 (TBW – IBW) + IBW x Monitor serum trough levels. Max of 3gms, increase
frequency Abbreviations: IBW= ideal body weight, TBW=total body weight, DW=Dosing
weight (use correction factor (CF)), MD=maintenance dose, LD=loading
dose BACKGROUND In general, the volume of distribution (Vd) of hydrophilic
drugs relates better to lean body mass because of poor penetration into adipose
tissue and the Vd of lipophilic drugs correlates better with total body weight
because of good penetration into adipose tissue8-10. HYDROPHILIC3 LIPOPHILIC > B-lactams
- Penicillins - Cephalosporins - Monobactams - Carbapenems > Daptomycin
> Glycopeptides
- Vancomycin > Aminoglycosides
> Polymyxins
> Aztreonam
> Fluoroquinolones
> Macrolides
> Lincosamides
> Linezolid
> Tetracyclines
> Tigecycline
> Sulfamethoxazole/trimethoprim
> Rifampin
CREATININE CLEARANCE IN OBESITY19-27 Obese patients tend to have a higher creatinine
clearance. Commonly used
equations to estimate creatinine clearance( CrCl) may not be accurate
predictors of clearance in the obese. The Cockcroft-Gault formula is less accurate when total body weight
(TBW) is used to estimate CrCl in obese patients21.
The Salazar-Corcoran formula appears to be the more accurate
of all the currently available renal function formulas9. When a lean body weight (LBW) estimate, based on TBW and
body mass index (BMI) was used in the Cockcroft-Gault equation, it provided an
accurate, relatively precise estimate of CrCl27. Salazar-Corcoran on line calculator19 Male: (137 – age) x ([0.285 x TBW] + [12.1 x height
in meters]2) 51 x SCr Female: (146
– age) x ([0.287 x TBW] + [9.74 x height in meters]2) 60 x SCr TBW = total body weight (kg) Cockcroft-Gault using Adjusted Body Weight (Adj. BW) on line calculator 22 Male: (140-age) x Adj. BW IBW
male: [2.3 + (height(in) –
60] + 50 72 x SCr
Female: (140 – age) x Adj. BW x 0.85 IBW
female: [2.3 + (height(in) –
60)] + 50 72
x SCr Adj. BW: (TBW
– IBW) x 0.4 + IBW Cockcroft-Gault using Lean Body Weight (LBW) on line calculator 27 Male: (140-age) x LBW LBW
male: 9270 x TBW 72 x SCr 6680 +216 x BMI Female: (140-age) x LBW x 0.85 LBW
female: 9270
x TBW 72 x SCr 8780 +244 x
BMI Body Mass Index (BMI) on line calculator BMI = Weight (lbs) x 703 Height2 (in2) References 1.
Overweight and obesity: home. Department of Health and Human Services: centers
for Disease Control and Prevention. Accessed
at:http://www.cdc.gov/nccdphp/dnpa/obesity/index.htm. Updated 2009 Aug 27.
Accessed September 13, 2009.
2.
Falagas ME, Karageorgopoulos DE. Adjustment of dosing of antimicrobial agents
for bodyweight in adults. Lancet. 2010; 375: 248-251. 3.
FalagasME, Athanasoulia AP, Peppas G, Karageorgopoulos DE. Effect of body mass
index on the outcome of infections: a systematic review. Obes Rev 2009; 10:
280-89. 4.
Falagas ME, Kompoti M. Obesity and infection. Lancet Infect Dis 2006; 6:
438-46. 5.
Bosma RJ, Krikken JA, HJoman van der Heide JJ, de Jong PE, Navis GJ. Obesity
and renal hemodynamic's. Contrib Nephrol 2006.; 151: 184-202. 6.
Wurtz R, Itokazu G, Rodvold K. Antimicrobial dosing in obese patients. Clin
Infect Dis 1997; 25 (1):112-8. 7.
Cheymol G. Effects of obesity on pharmacokinetics implications for drug
therapy. Clin Pharmacokinet 2000; 39 (3):215-31. 8.
Bearden DT, Rodvold KA. Dosage adjustments for antibacterials in obese patients
applying clinical pharmacokinetics. Clin Pharmacokinet 2000; 38 (5):415-26.
9. Pai
MP, Bearden DT. Antimicrobial dosing considerations in obese adult patients.
Pharmacotherapy 2007;27:1081..
10.
Blouin RA, Kolpek JH, Mann HJ. Influence of obesity on drug disposition. Clin
Pharm 1987; 6 (9):706-14. 11.
Vachharajani V, Vital S. Obesity and Sepsis. J Intens Care Med 2006;
21(5):288-95. 12.
Han PY, Duffull SB, Kirkpatrick CMJ, Green B. Dosing in obesity: a simple
solution to a big problem. Clin Pharm Ther 2007; 82(5):505-8. 13.
Dellit TH, Owens RC, McGowan JE et al. Infectious diseases society of America
and the society for healthcare epidemiology of America guidelines for
developing an institutional program to enhance antimicrobial stewardship. Clin
Infect Dis 2007; 44:159-77. 14.
Owens RC. Antimicrobial stewardship: application in the intensive care unit.
Infect Dis Clin North Am 2009; 23(3) 683-702. 15.
Owens R, Ambrose PG, Nightingale CH. Antibiotic Optimization. Taylor &
Francis Group 2005. Boca Raton, FL. Pg 261-326.
16. Bauer LA, Edwards WA, Dellinger EP et al. Influence of
weight on aminoglycoside pharmacokinetics in normal weight and morbidly obese
patients. Eur J Clin Pharmacol 1983; 24 (5):643-7. 43. Caldwell JB, Nilsen AK. Intravenous ciprofloxacin
dosing in a morbidly obese patient. Ann Pharmacother 1994; 28 (6):806. 44.
Hollenstein UM, Brunner M,
Schmid R, et al. Soft tissue concentrations of ciprofloxacin in obese and lean
subjects following weight-adjusted dosing. Int J Obes Relat Metab Disord
2001;25:354. 45.
Allard S, Kinzig M, Boivin G et al. Intravenous ciprofloxacin disposition in
obesity. Clin Pharmacol Ther 1993; 54 (4):368-73.
46. Boccazzi A, Langer M, Mandelli M, Ranzi AM, Urso R. The pharmacokinetics of
aztreonam and penetration into the bronchial secretions of critically ill
patients. J Antimicrob Chemother.
1989 Mar;23(3):401-7.
47.
Erstad BL. Dosing of medications in morbidly obese patients in the intensive
care unit setting. Intensive Care Med 2004; 30 (1):18-32. 48.
Honiden S, McArdle JR. Obesity in the intensive care unit. Clin Chest Med 2009;
30:581-599. 49.
Dvorchik BH, Damphousse D. The pharmacokinetics of daptomycin in moderately
obese, morbidly obese, and matched nonobese subjects. J Clin Pharmacol 2005; 45
(1):48-56. 50.
Pai MP, Mercier RC, Allen SE. Using vancomycin concentrations for dosing
daptomycin in a morbidly obese patient with renal insufficiency. Ann
Pharmacother 2006; 40:533-8. 51.
Pai MP, Norenberg JP, Anderson T et al. Influence of obesity on the single-dose
pharmacokinetics of daptomycin. Antimicrob Agent Chemo 2007; 51(8):2741-47. 52.
Cohen LG, DiBiasio A, Lisco SJ et al. Fluconazole serum concentrations and
pharmacokinetics in an obese patient. Pharmacotherapy 1997; 17 (5):1023-6. 53.
Penk PL. Special pharmacokinetics of fluconazole in septic, obese, and burn
patients. Mycoses 1999; 42(2):87-90. 54.
Stein GE, Schooley SL, Peloquin CA et al. Pharmacokinetics and pharmacodynamic's
of linezolid in obese patients with cellulitis. Ann Pharmacother 2005; 39
(3):427-32. 55.
Mersfelder TL, Smith CL. Linezolid pharmacokinetics in an obese patient. Am J
Health-Syst Pharm 2005;62:464, 467. 56.
Bauer LA, Black DJ, Lill JS. Vancomycin dosing in morbidly obese patients. Eur
J Clin Pharmacol 1998; 54 (8):621-5. 57.
Blouin RA, Bauer LA, Miller DD et al. Vancomycin pharmacokinetics in normal and
morbidly obese subjects. Antimicrob Agents Chemother 1982; 21 (4):575-80. 58.
Vance-Bryan K, Guay DR, Gilliland SS et al. Effect of obesity on vancomycin
pharmacokinetic parameters as determined by using a Bayesian forecasting
technique. Antimicrob Agents Chemother 1993; 37 (3):436-40. 59.
Hall RG, Payne KD, Bain AM. Multicenter evaluation of vancomycin dosing:
emphasis on obesity. Am J Med 2008; 121:515-18. 60.
Ducharnme MP, Slaughter RL, Edwards DJ. Vancomycin pharmacokinetics in a
patient population: effect of age, gender, and body weight. Ther Drug Monit
1994; 16:513-18. 61.
Lodise TP, Lomaestro B, Graves J, Drusano GL. Larger vancomycin doses (at least
4 grams per day) are associated with an increased incidence of nephrotoxicity.
Antimicro Agent Chemo 2008; 52:1330-36.
62.
Nasraway SA Jr, Albert M, Donnelly AM, Ruthazer R, Shikora SA, Saltzman E.
Morbid obesity is an independent determinant of death among surgical critically
ill patients. Crit Care Med 2006;34:964–70.