Antibiotic - Clinical Pearls

Front 1

-Na+ content (ex. pipercillin/tazobactam = Na+ content of 1 gram = 2.35mEq)

-removal during dialysis/pregnancy category

-Pen G or ampicillin + gentamicin (Enterococcus endocarditis)

-ampicillin + gentamicin (Listeria sp)

Back 1

Penicillins

Front 2

Meningitis:
-(Haemophilus influenza) ceftriaxone, cefotaxime, cefuroxime
- (Neisseria meningitidis)ceftriaxone and cefotaxime

-MTT side chain – cefamandole, cefmetazole, cefoperazone, cefotetan

-Pseudomonas sp. – ceftazidime, cefepime

-CAP – ceftriaxone + macrolide

-Lyme’s disease (Borrelia burgdorferi) (Stage II and III) – ceftriaxone

-febrile neutropenia – cefepime, ceftazidime and ciprofloxacin + pipericillin

Back 2

Cephalosporins

Front 3

- avoid as empiric therapy unless patient is hemodynamically unstable and showing signs of sepsis/severe sepsis

- anaphylactic allergy to penicillins, -lactams or cephalosporins

– 10% cross-reactivity

- limit as last resort due to higher development of resistance

Back 3

Carbapenems

Front 4

- monocyclic b-lactam nucleus are structurally different from other b-lactams including penicillins,

- cephalosporins – cross reactivity is rare

- Hemodialysis patients – 25% of usual dose Q6-12 hours

- combination for synergy (e.g. aminoglycosides - P. aeruginosa)

Back 4

Monobactams

Front 5

- DOC in patients failed/allergic to penicillins and cephalosporins

- not dialyzable, new high flux filters may affect levels

- Draw levels two hours after end of dialysis (Vd equilibrium)

- evaluate levels for accuracy
serum concentrations monitoring necessary? Effect patient outcome?

- audiology testing may be required

- no serum levels!!!

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Glycopeptides

Front 6

- poor penetration into pulmonary secretions and inactivated by pulmonary surfactant– not indicated for pulmonary infections

-commonly used in home infusion therapy

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Lipopeptides

Front 7

- CAP – combo w/ 3rd gen cephalosporin

- Food: consider effects on absorption if oral admin

-clarithromycin – pharyngitis, sinusitis, AECB, pneumonia, skin (only PO)

- erythromycin – respiratory and skin structure PID (PO and IV)
azithromycin - pharyngitis, acute otitis media, gonococcal infections, PID
and skin structure, PID (PO and IV)
Microbacterium Avium Complex (MAC)

– combo with ethambutol, rifabutin or ciprofloxacin
photosensitivity reactions

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Macrolides

Front 8

- pregnancy category D – do not use during pregnancy

- doxycycline may be used as a sclerosing agent for pleural effusion

- doxycycline is DOC for Stage I Lyme disease

- permanent discoloration of teeth (during child development < 8)

- other uses – gonorrhea, syphilis, PID

Back 8

Tetracyclines

Front 9

- permanent discoloration of teeth (last trimester of pregnancy,
infancy up to 8 yrs of age)

- mixed success for MDR Acinetobacter baumannii infections

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Glycylcyclines

Front 10

- extensive drug interactions (weigh risk vs benefit)

Contraindications: Myasthenia gravis – respiratory failure and deaths have been reported

- contraindicated – cisapride, pimozide (increase QTc interval)

Back 10

Ketolides

Front 11

can be used for bacterial endocarditis prophylaxis, PID, PCP pneumonia, diabetic foot and intra-abdominal infections. Topical may cause “glowing of the skin” under black light

Back 11

Lincosamides

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traditionally used in synergy ( lactam, cephalosporin, etc…)

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Aminoglycosides

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treatment of 1st choice for C. difficile in clinical practice – should be given in oral form for maximum efficacy. May need to give higher doses IV due to enterohepatic circulation

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Metronidazole (Flagyl)

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- limited use in clinical practice due to severe side effect profile – used primarily for VRE if intolerant to other agents (oxalodinones)

- may be used for meningitis (very good CNS penetration)

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Chloramphenicol (Chloromycetin)

Front 15

- not indicated for Enterococcus faecalis/ limited spectrum of activity

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Streptogramin

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- Preferred over quinupristin/dalfopristin for VRE

- covers both Enterococcus faecium and faecalis

- has greater FDA approved indications

- limited drug interactions (No CYP metabolism)

- may be switched IV to PO – significant cost savings

- linezolid + MAO + serotonin agonist = hypertensive crisis

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Oxalodinones

Front 17

- may discolor body fluids – urine, tears, sweat to red-orange color. May -permanently stain soft contact lenses
monitor LFTs at baseline and every 2-4 weeks during therapy

- not altered by HD or peritoneal dialysis

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Rifampin (Rifadin)

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- AUIC for fluoroquinolones – major determinant of efficacy
may be used if penicillin or cephalosporin allergy

- switch from IV to PO after 72 hrs of IV or if patient can take PO and is afebrile for 48 – 72 hrs (cost savings)
100% bioavailability of IV and oral

- avoid in children < 18 years of age

- osteochondrosis/arthropathy

- affects ability to grow!

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Fluoroquinolones

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- Dosing must be adjusted for renal dysfunction

- Bactrim: DOC in clinical practice

- IV formulation (fluid overload)

- consider drug/drug interactions

- folic acid antagonist-folic acid anemia if on prophylaxis

- PCP pneumonia/sulfa allergy – desensitize patient

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Sulfonamides

Front 20

- Treat enterococcus faecalise (G+)

- poor drug: not much activity

- prophylaxis: microbial resistance

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Nitrofurantoin (Macrobid)