Antibiotics for Family Physicians - PBworksunmfm.pbworks.com/w/file/fetch/62672811/2Final.Family.Medicine.Abx...Antibiotics for Family Physicians Sarah E. Allen, MD November 28, 2012

Antibiotics for Family Physicians

Sarah E. Allen, MD

November 28, 2012

“I just use imipenem for everything.”

--Anonymous Physician

Dr. Allen’s lecture was like…

“…like having the PDR read to me.”

Antibiotics 2012

• Penicillins

• Cephalosporins (23)

• Monobactam (Aztreonam)

• Carbapenems

• Aminoglycosides

• Clindamycin

• Daptomycin

• Linezolid

• Sulfa

• Metronidazole

• Fluoroquinolones

• Rifamycin

• Macrolides

• Fosfomycin

• Tetracyclines

• Colistin

• Nitrofurantoin

• Synercid

• Vancomycin

Staphylococci Streptococci Enterococci Gram positive anaerobes (Mouth, Peptostrep, Clostridium) Gram negative anaerobes (Below the belt, Bacteroides)

E. Coli Klebsiella Enterobacter

Pseudomonas

Montessori Microbiology

Staphylococci Streptococci Enterococci

Gram positive anaerobes (Mouth, Peptostrep, Clostridium) Gram negative anaerobes (Below the belt Bacteroides) E. Coli Klebsiella Enterobacter

Pseudomonas

Montessori Microbiology

Montessori Antibiotics* *Dr. Allen is still working on this

Gram Positives Gram Negatives Vancomycin----------------------- Nafcillin Daptomycin------------------- Linezolid----------------------- Cefazolin--------------------- ------------------- Penicillin----------------------------- Bactrim---------------------------- ----- Clinda- - - - - ------------------------------------------------ Minocycline- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > --------------Flagyl --------------------------------------------------------------------------ertepenem ----------------------------------- ------------------gentamicin ---------------------------------- ------------------tobramycin Moxiflox------------- - - - - - - - - - - ---------------------------------------- Cipro---- ---------------------Cipro-- ----------------------------- ------------------cefepime --------------------------------------------------------------------------------------------imipenem

+ Anaerobes -

M R

S A

For Today…

• Principles of antibiotic use

• Staph antibiotics

• Making sense of the #$*# beta-lactam class – Penicillins – Cephalosporins – Carbapenems

• 2 more classes – Macrolides – fluroquinolones

• Please invite me back for Parts 2-????!

– UTI – Respiratory Tract infections (sinus, ear, lungs) – Sepsis – Diabetic Feet – OPAT services

Principles of Antibiotic Use in the outpatient setting

• Try not to use antibiotics • Education

– Resistance – Superinfection (Yeast, C. Diff)

• Safety Net Antibiotic Prescription (SNAP) – Ear infections in children – Sinus infections – Bronchitis

• Prevention of infection – Immunization – Treat underlying disease

• Allergies

Principles of Antibiotics in the inpatient setting

• Guidelines can be helpful

• Stanford can be helpful

• Shotgun approach is often necessary – Vancomycin + Zosyn

– Await cultures, further evaluation, consultation

• Use “cidal” antibiotics rather than “static”

• Use complimentary mechanisms of action

• Narrow antibiotic spectrum if you can

Mechanisms of Action

• “Oh please, Dr. Allen, not that!” • Cell wall antibiotics

– Beta-lactams – Vanco – Daptomycin

• Protein synthesis antibiotics – Clindamycin – Macrolides

• Ribosomal antibiotics – aminoglycosides

• DNA gyrase (supercoiling) antibiotics – Cipro

• Folate synthesis antibiotics – Sulfa drugs

Staphylococcus (Catalase producers)

Coagulase Producing

• Staph aureus

Coagulase negative

• Coagulase Negative Staph

• CONS

• Staph epidermitis

• Staph saprophyticus

• Staph everythingelseicus

Staphylococcus Aureus

Staphylococcus aureus

Methicillin Sensitive

• Methicillin sensitive

• Oxacillin sensitive

• Nafcillin sensitive

• Dicloxacillin sensitive

• Cephalosporins sensitive

Methicillin Resistant

• Methicillin resistant

• Oxacillin resistant

• Nafcillin resistant

• Dicloxacillin resistant

• Cephalosporin resistant – Except Ceftaroline

Outpatient Staph Treatment

MSSA

• Keflex

• Augmentin

• Dicloxacillin

MRSA

• Minocycline (doxycycline)

• Bactrim

• Clindamycin

• Zyovx $$$$

Prevention of Staph Skin Infectious

• What is the underlying skin condition?

• The skin is the portal of entry

• Eczema, psoriasis, dry skin, contact dermatitis, acne, prurigo nodularis, shaving, deodorant, onychomycosis, athlete’s foot, excessive hand-washing

Very early home treatment for Staph

• Wet warm soaking – Heat brings blood to the area

– Must be wet heat

– Apply warm (almost hot) wash cloth repeatedly

– Soak in warm water in bath or bucket

• Apply topical anti-Staph ointment – Gentamicin (ophthalmic ointment)

– Mupiricin

Inpatient Staph Infections

MSSA

• Nafcillin

• Beta-lactamase inhibitor – Unasyn

– Zosyn

• Cefazolin

MRSA

• Vancomycin

• Bactrim

• Clindamycin

• Ceftaroline

• Tigecycline

• Zyvox

• Daptomycin

Beta-Lactams

• Penicillins

• Cephalosporins

• Carbapenems

• Monobactam

Penicillins

• Penicillins

• Ampicillins

• Pseudomonas Penicillins

• Beta-lactamase inhibitor antibiotics

Penicillin

• A drug for streptococcus

• No Staph coverage

• “Pssst!”

– A very few gram-negative organisms (Neisseria)

– Syphilis

– Mouth anaerobes (dentists use PCN all the time!)

– Human, dog, cat bite organisms

Ampicillin

• A drug for Streptococcus

• A drug for Enterococcus (usually with Gent)

• Some H. Flu (non-beta-lactamase producers)

• No Staph Coverage

• “Pssst!” – This has a little better gram negative coverage than

penicillin but is pretty weak.

– Few E. Coli for UTIs

Pseudomonas Penicillins

• Piperacillin

• Has beens: Ticarcillin

• Once in a while: carbenicillin (oral)

Piperacillin

• This is not the same as Zosyn=Pip/Tazo

• Piperacillin – This is a drug for Streptococcus

– A drug for Pseudomonas and other gram negatives

– No Staph coverage

• Pit falls – Not a drug for Staph

– Not for all H. Flu (only those without B-lactamase)

Beta-Lactamases and their inhibitors!!

• Beta-Lactamases – Many, many types

– Destroy all penicillins

• Enter the Beta-Lactamase inhibitors – Molecules that suck away beta-lactamases

– act as a decoy • Clavulanate

• Sulbactam

• Tazobactam

B-Lactams + B-Lactamase inhibitors

• Amoxicillin + Clavulanate (Augmentin)

• Ampicillin + Sulbactam (Unasyn)

• Piperacillin + Tazobactam (Zosyn)

B-Lactams + B-Lactamase inhibitors

• Amoxicillin + Clavulanate (Augmentin) • Ampicillin + Sulbactam (Unasyn)

• Parent drug (Amp/Amox)

– A drug for Streptococcus – Wimpy Gram negative coverage – Oral anaerobes, but not below the belt Bacteroides

• Parent drug + inhibitor – Saves the parent! – Allows “wow” broad spectrum coverage

• Staph (MSSA)* • E. Coli • Klebsiella • Bacteroides fragilis!!!!

• *Remember: MRSA=resistance to all B-lactams

B-Lactams + B-Lactamase inhibitors

• Piperacillin + tazobactam = Zosyn

• Parent drug: piperacillin • Strep + Anti-pseudomonal gram-negative coverage • No better than penicillin for anaerobes (mouth) • No Staph coverage

• Zosyn • “wow” coverage

• Staph (MSSA) coverage • Pseudomonas • Better gram-negative coverage for more B-lactamase producers • Below the belt anaerobic coverage (Bacteroides)

Why do we need broad spectrum drugs?

• In a perfect world, there would be one drug for each bug we want to kill – More drugs like nafcillin (just Staph/MSSA) – Fewer drugs like imipenem (everything except MRSA +

Stenotrophomonas)

• Broad spectrum drugs are used for

– Empiric treatment • Pneumonia • Neutropenic fever • Sepsis

– Polymicrobial treatment • Bite wounds • Abdominal sepsis • DM foot ulcers

ESBL: Extended Spectrum Beta Lactamase Producing Bacteria

• Patients with recurrent UTIs • Do not use Zosyn even if it’s listed as sensitive!! • Use a carbapenem • All carbapenems

– have great anaerobic coverage – Very broad spectrum (Staph to Pseudomonas)

• Unique mechanism (porin entry) – Ertepenem

• Once a day • No anti-Pseudomonal coverage

– Imipenem – Meropenem – Doripenem

Cephalosporins

• PDR time! • Stanford lists over 20 • Most of the “useful” Cephalosporins

– MSSA – Streptococcus/Pneumococcus – E. Coli – Klebsiella

• Cefazolin IV (Orthocillin) • Cephalexin PO (Orthocillin) • Ceftriaxone (Home-a-cillin): meningitis, SBP, PNA • Cefepime (anti-Pseudomonal)

Fluoroquinolones

• Unique mechanism – DNA gyrase inhibitor – Prevents supercoiling of DNA – The Cell is a mess of DNA strewn everywhere!

• Cipro – Staph/MSSA – Pseudomonas and other gram negatives

• Moxifloxacin – Better Strep (respiratory flora) – Anaerobic coverage – No Pseudomonas – No UTI!!!!

• Ask every patient if they take chalky antacids or “divalent cations” (Ca, Fe, Zn, Mg)

• Adverse reactions: CNS, sun-exposure, QT prolongation

Macrolides

• Zithromax for President! – “Respiratory” infections

• Sinus, ears, lungs

– “Recreation” infections • Chlamydia

• GC

• Remember Biaxin (Clarithromycin)? – MAC treatment

– H. Pylori

Take Home Points

• This is complicated stuff!

• Please call PALS anytime.

• Don’t you think there should be an antibiotic ECHO?

• We can decrease antibiotic use – immunizations

– hand-washing

– education

– safety net antibiotic prescriptions (SNAP)

What’s better than an antibiotic?

• Glycemic control • Intact skin • Good blood supply • Relieving an obstruction • Absence of nicotine • Immunizations • Clean water • Breast feeding • Hand washing • Preventive Health Care

Thank you