Infectious Disease Compendium

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Heres how we do it at Good Sam (special thanks to Janet Perry our intrepid pharmacist for putting this together).

Patients excluded from these guidelines:

1. Patients with ESRD or CrCl <30 (Dose these patients with 15mg/kg (TBW) and check serum trough level 3-7 days later to ensure trough remains 15-20 for MRSA).

2. Adult patients with actual body weight <50kg or >130kg.

3. Adult patients in a hypermetabolic state e.g. burn and trauma cases and IVDA, may need increased dose.

4. Pediatric patients.

Dosing

Best way? Order "Pharmacy to dose". They know better than you.

1. Calculate Creatinine Clearance (Creatinine Clearance Formula).

2. Select dose from chart using

CrCl and patients weight in KG (use total body weight).

Monitoring guidelines:

1. Order serum trough concentration if necessary once patient at steady state per recommendations below. (no peak level required. Usually).

2. Interpret Serum trough level (Desired target range 5-16; 15-20 for MRSA).

a. If level within target range and renal function stable-continue present dose.

b. If level <5, increase dose or decrease dosing interval.

c. If level >16, increase dosing interval.

d. Order an additional trough concentrations) at steady state if dose adjustment made and therapy is continued.

Patients NOT requiring trough level

1. Empirical therapy lasting <5 days.

2. Therapy lasting >5 days but patient clearly improving using monitoring parameters in above and patient has stable renal function.

3. Postoperative prophylactic therapy (no documented infection).

There are few things as stupid as getting a level on day 2 and then stopping the drug on day 3. Lets use the brain in our skull, OK people?

Patients that may require trough vancomycin levels

1. On concomitant potentially nephrotoxic therapy (aminoglycoside, amphotericin B, cyclosporin, ACE, NSAID'S, Loop Diuretic, Contrast Agent).

2. Unstable / deteriorating renal function.

3. Patients requiring doses higher than those on the guideline table.

4. Patients on vancomycin >5 days and not improving.

5. Critically ill patients.

6. Burn patients.

7. Patients expected to be on long-term therapy (e.g. endocarditis, osteomyelitis- aim for trough level of 10-16 in these patients).

8. Patients being treated for a serious enterococcal or MRSA infection.

Total Patient Weight //

CrCl

30
40
50
60
70
80
90
100
110
50 kg
500mg q24H (28/14)
750mg q24h (35/15)
750m q24h (31/11)
1000mg q24h (38/11)
500mg q12h (26/13)
500mg q12h (24/11)
750mg q12h (34/14)
750mg q12h (32/12)
750mg q12h(31/10)
55 kg
500mg q24h (25/13)
750mg q24h (32/14)
1000mg q24h (38/13)
1000mg q24h (35/10)
500mg q12h (24/12)
750mg q12h (33/15)
750mg q12h (31/13)
1000mg q12h (38/15)
1000mg q12h (36/13)
60 kg
500mg q24h (23/12)
750mg q24h (29/12)
1000mg q24h (35/12)
1000mg q24h (32/9)
750mg q12h (33/16)
750mg q12h (30/14)
750mg q12h (28/12)
1000mg q12h (35/13)
1000mg q12h (33/12)
65 kg
750mg q24h (32/16)
1000mg q24h (36/15)
1000mg q24h (32/11)
1500mg q24h (44/13)
750mg q12h (30/15)
750mg q12h (28/13)
1000mg q12h (34/14)
1000mg q12h (32/12)
1000mg q12h (31/11)
70 kg
750mg q24h (30/15)
1000mg q24h (34/14)
1000mg q24h (30/10)
1500mg q24h (41/12)
750mg q12h (28/14)
1000mg q12h (34/16)
1000mg q12h (32/13)
1000mg q12h (30/12)
1000mg q12h (29/10)
75 kg
750mg q24h (28/14)
1000mg q24h (31/13)
1000mg q24h (28/10)
1500mg q24h (38/11)
750mg q12h (26/13)
1000mg q12h (32/15)
1000mg q12h (30/13)
1000mg q12h (28/11)
1000mg q12h (27/9)
80 kg
750mg q24h (26/13)
1000mg q24h (29/12)
1500mg q24h (39/14)
1500mg q24h (36/10)
1000mg q12h (33/16)
1000mg q12h (30/14)
1000mg q12h (28/12)
1000mg q12h (26/10)
1000mg q12h (25/9)
85 kg
750mg q24h (25/13)
1000mg q24h (28/12)
1500mg q24h (37/13)
1500mg q24h (34/10)
1000mg q12h (31/16)
1000mg q12h (28/13)
1000mg q12h (26/11)
1500mg q12h (37/14)
1000mg q8h (30/15)
90 kg
1000mg q24h (31/16)
1000mg q24h (26/11)
1500mg q24h (35/12)
1500mg q24h (32/9)
1000mg q12h (29/15)
1000mg q12h (27/12)
1000mg q12h (25/10)
1500mg q12h (35/13)
1000mg q8h (28/14)
95 kg
1000mg q24h (29/15)
1000mg q24h (25/10)
1500mg q24h (33/11)
1500mg q24h (30/9)
1000mg q12h (28/14)
1000mg q12h (25/12)
1000mg q12h (24/10)
1500mg q12h (33/13/)
1000mg q8h (27/14)
100 kg
1000mg q24h (28/14)
1000mg q24h (24/10)
1500mg q24h (31/11)
1000mg q12h (29/16)
1000mg q12h (26/13)
1000mg q12h (24/11)
1500mg q12h (34/14)
1000mg q8h (27/15)
1000mg q8h (25/13)
105 kg
1000mg q24h (27/14)
1500mg q24h (34/14)
1500mg q24h (30/10)
1000mg q12h (28/15)
1000mg q12h (25/13)
1000mg q12h (23/11)
1500mg q12h (32/13)
1000mg q8h (26/14)
1000mg q8h (24/12)
110-130 kg
1000mg q24h (25/13)
1500mg q24h (32/14)
1500mg q24h (29/10)
1000mg q12h (26/15)
1000mg q12h (24/12)
1500mg q12h (33/15)
1000mg q8h (27/15)
1000mg q8h (25/13)
1000mg q8h (23/12)

Numbers in parentheses are the estimated peak/trough

Important side effects

Oto and nephro toxicity. Too rapid an infusion will cause a release of histamine and the patient will get and itchy red head/neck and chest. This is NOT an allergic reaction. Can be managed with a histamine blocker or slowing down the infusion.

Can cause an immune mediated thrombocytopenia (PubMed).

As we push the troughs to treat MRSA, the risk of ototoxicity increases, especially in those over 53 (PubMed) where it approaches 20%.

The IDSA guidelines for using Vancomycin against MRSA (PubMed):

Even for obese patients, initial vancomycin dosages should be calculated based on actual body weight.

A). The most accurate to monitor vancomycin effectiveness is trough serum vancomycin concentrations, measured just before the fourth dose.

B). Trough serum vancomycin concentrations should be greater than 10 mg/L. Trough serum vancomycin concentrations of 15 to 20 mg/L are recommended.

C) For seriously ill patients, give a loading dose of 25 to 30 mg/kg (based on actual body weight).

D) Most patients with normal renal function should receive vancomycin dosages of 15 to 20 mg/kg (based on actual body weight) given every 8 to 12 hours.

E) In the absence of an alternative explanation, a patient should be considered to have vancomycin-induced nephrotoxicity if there are at least 2 or 3 consecutive high serum creatinine concentrations (increase of 0.5 mg/dL or 150% increase from baseline, whichever is greater) after several days of vancomycin therapy

F) All patients treated with vancomycin for 5 days or more should have at least 1 steady-state trough serum concentration measured just before the fourth dose. Frequent monitoring is not recommended for treatment lasting less than 5 days or for lower-intensity dosing targeted to achieve trough serum vancomycin concentrations of less than 15 mg/L.

G) Check trough concentrations once a week in stable patients, more often if GFR is fluctuating.

Important drug interactions

Amikacin, gentamicin, metformin, rapacuronium, succinylcholine, tobramycin, warfarin.

When added to piperacillin-tazobactam it is associated with acute kidney injury (PubMed)(PubMed).

.

A meta-analysis suggests an odds ratio of 3 for AKI (PubMed) when combined with zosin.

Rants and Screeds

It is a shitty drug: mostly static, toxic, lousy pharmacokinetics, penetrates poorly into all tissues. When compared to beta lactams, it is always worse. Don't use it unless you have NO choice. Never ever opt for Vancomycin just because its easier to give (PubMed). Outcomes are worse.

Pearls

It has zero po absorption. That is zero as in nothing. And even in 2011 I see the occasional patient put on po vancomycin for some sort of MRSA infection, seriously dude, it you are that clueless, time to pack it in. It is ONLY used po for C. difficile

Here is some weirdness: vancomycin and gentamicin can make you fat. "A major and significant weight gain can occur after a six-week intravenous treatment by vancomycin plus gentamicin for IE with a risk of obesity, especially in males older than 65 who have not undergone surgery. We speculate on the role of the gut colonization by Lactobacillus sp, a microorganism intrinsically resistant to vancomycin, used as a growth promoter in animals, and found at a high concentration in the feces of obese patients (Plos)."

Treatment of choice

Gram positive organisms, Staphylococcus aureus (methicillin resistant), Clostridium difficile.

Use for

Anthrax, atypical Mycobacterium infection, Bacilluss, Catheter Infections, Corynebacterium infections, Empyema, Endocarditis, intraocular infections, Prosthetic Joint Infection, Listeria monocytogenes, Meningitis, Staphylococcus aureus (methicillin resistant)i, Neutropenic fever, Peritonitis, Pseudomembranous Colitis, staphylococcal enterocolitis, staphylococcal infections, Streptococci, surgical prophylaxis.

Don't use for

Anything if you have the choice of a beta-lactam.

Class

Glycopeptide.