Antibiotics

Front 1

abx known

Back 1

1. spectrum of activity: abx coverage of bacteris
2. MOA
3. Adverse effects and toxicities
4. Tissue penetration

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abx

Back 2

-kill bacteria without harming the host (selective toxicity)
-empiric therapy (best guess) broad spectrum to cover most likely infecting agents (choose based on site, gram stain)
-narrow focused therapy is begun ASAP after getting results of C&S from infected site (minimize resistance to broad spectrum agents)

Front 3

bactericidal vs. bacteriostatic

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1. kills bacteria
2. abx inhibit growth of actively replicating; ok with a mild infx in an immunocompetent host- not good for immunocompromised

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gram positive cocci

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1. Streptococci
-pneumococci
2. Staphylococci
-normally inhibit skin and cause: abscesses
3. Empiric tx is:
-Nafcillin, dicloxacillin
-cephalexin, cefazolin
4. Enteroccoci- (usually in colon or perianal) innately resistant to many abx

Front 5

penicilins and cephalosporins

Back 5

-inhibit formation of peptide bridges in petidoglycan of gram + and gram - bacteria

Front 6

gram negatives

Back 6

-encased by an outer membrane with LPS and protein channels
1. Enterics: E.coli, shigella, salmonella, serratia (inhospitalized pts cause pneumonia), proteus, enterbacter, klesiella
2, Haemophilus influenzae
3. **Pseudomonas- resistance so requires specific therapy-veryy difficult to treat

Front 7

neisseria

Back 7

-gram neg dipploccus
-gonorrhea and meningitis

Front 8

anaerobes

Back 8

-no O2, foul-smelling deep tissue infections
1. Bacteriodes fragilis- most common (internal abcesses)
2. Clostridia spp. (gangrene)
3. Prevotella (gingival pockets)
4. Peptostretococcus
5. need special abx: Clindamycin, Metronidazole

Front 9

common syndromes of anaerobic infxs

Back 9

1. bite infxs
2. oral or dental infx
3. aspiration penumonia, lung abscess
4. appendicitis

Front 10

probiotics

Back 10

-live, friendly organisms in intestine which may balance pathogenic organisms that cause diarrhea and yeast infections
(Bifidobacteria, lactobacillus, saccaromyces)-avail as cultures in yogurts, capsules, tables, packets
-may help IBS, IBD, certain diarrhea and recurrent yeast infxs
-abx can hurt these

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Beta- lactam Abxs

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-Transpeptidase and penicillin binding proteins (PBPs) crosslink units of petidoglycan cell wall
-PCNs and cephalosporins are beta-lactam abx that bind and inactivate transpeptidases and PBPs and trigger autolysis--> destroy cell wall
-PCN nucleus and side chains = R

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Natural penicillins (PCN G (iv) and VK (po)

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-susceptible to beta lactamases produced by resistant bacteria
-Coverage- gram POSITIVE (best), gram negative, few anaerobes, treponema, streptococci, pneumococci, meningococci, listeria monocytogenes
-PCN VK oral form for strep throat (TID)

Front 13

Benzathine PCN

Back 13

IM formulation version of natural PCN
-depot --> deposited slowly in muscle
-used for strep throat and syphillis

Front 14

beta lactamases

Back 14

-variety of different enzymes that make bacteria--> destroy beta-lactam ring

Front 15

PCNs- Anti-staphylococcal

Back 15

-resistant to hydrolysis by staphylococcal beta lactamases
-MOND:
1. Methicillin (nephrotoxic- not used anymore)
2. Oxacillin
3. Nafcillin (IV, IM)
4. Dicloxacillin (po)- for mild skin infx, mastidis
-Used for beta lactamase + staph infections!
-Problem: Methicillin resistant staph aureus (MRSA)

Front 16

Extended-spectrum PCNs

Back 16

-greater gram - coverage
1. Ampicillin po/IV
2. Amoxicillin po
3. Ticarcillin- pseudomonas
4. Piperacillin – pseudomonas
-extended spectrum into gram - realm (also cover gram positives)

Front 17

Extended-spectrum PCNs uses

Back 17

1. susceptible sinusitis
2. respiratory infx
3. otitis media
4. pseudomonas infxs

Front 18

beta-lactamase inhibitors

Back 18

-chemicals given with beta lactam abx to inhibit beta lactamases
1. Clavulanic acid + amoxicillin = augmenten (PO)- sinusitis, recurrent otitis media; diarrhea common AE
2. Sulbactam + ampicilin = Unasyn (IV, IM): for bite
3. Tazobactam + piperacilin --> Zosyn (IV)- pseudomondas infxs
-Ticaricillin + clavulinic acid- severe pesudomonas infxs

Front 19

pharmacology of the PCNs

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-poor CNS penetration except when meninges are inflammed (combined with something else)
-Category B

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PCNs AE

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1. hypersensitivity rxns: rash
2. Interstitial nephritis
3. GI intolerance & diarrhea
4. rash with EBV mononucleosis (amox and amp)

Front 21

Beta lactams- Cephalosporins and Cephamycins (10-15% x-reactivity with PCNs)

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-more stable than PCNs to B-lactamases produced by several bacteria
-1st gen: better G+ activity
-2nd gen: inc activity against G -
-3rd gen: G- rod, some pseudomona; less G+
-4th gen: inc stability to B lactamases and more extended spectrum than 3rd gen

Front 22

1st generation cephalosporins

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1. Po Cephalexin (Keflex)
2. IV Cefazolin (ancef) (used for most surgical prophylaxis unless it is GI/ pelvic procedure then use Cefotetan-esp orthopedics)
-Used for staph skin infections, soft tissue infections such as furuncle and to prevent infection
-MRSA is resistant to these

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Second generation cephalosporins and cephamycins

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1. IV: cefotetan, cefuroxime, cefoxitin (PID)
2. Po: cefaclor, cefuroxime axetil (Ceftin)**, cefmetazole, cefprozil
-Cefoxitin, cefotetan are active against anaerobes (cephamycins)
uses: Po OM, sinusitis, lower resp. tract infxs, communit. aquired pneumonia
IV: gyn, surgical prophylaxis

Front 24

3rd Generation Cephalosporins

Back 24

1. PO: cefixime (gone now), ceftibuten, cefpodoxime, CEFdinir
2. IV: Ceftriaxone, cefotaxime --> meningitis cross BBB!!
3. Pseudomonas coverage: Ceftazidime*, cefoperazone
4. Moxalactam and ceftizoxime cover B. fragilis

Front 25

Fourth Generation Cephalosporins

Back 25

1. Cefepime IV only
-More resistant to hydrolysis by enterobacter’s beta lactamases but otherwise similar role to 3rd generation
-

Front 26

Cephalosporins- Basic Pharmacology

Back 26

-renal excretion
-variable CNA penetration
-pregnancy category B

Front 27

cephalosporins AE

Back 27

1. Hypersensitivity reactions
2. Renal nephritis
3. Platelet dysfunction
4. Superinfection esp. with broad spectrum agents (infx caused by abx)

Front 28

Monobactam --> aztreonam

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-type of beta lactam
-only for gram neg rods
-IV only
-gram - sepsis
AE: skin rash and increased LFTs

Front 29

Carbapenems*

Back 29

-all IV
-Imipenem (+Cilistatin)
-also meropenem and ertapenam (Invanz)
-Doripenam (best against peudomonas of this group)
-BROAD SPECTRUM BIG GUN
-used for complicated infxs
-covers gram +, - and anerobes
AE: N/V and rarely seizures

Front 30

Vancomycin

Back 30

-BIG GUN-use prudently; IV and PO (C.diff)
-MOA:cell wall inhibitor
-use: fro gram + positive
-MRSA, sepsis and endocarditis
-enterococcus infxs (issues: VRE and VISA resistance to vanco)
-resistant pneumococcal meningitis

Front 31

vancomycin AE

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1. Local reactions
2. Fever, chills
3. Oto and nephrotoxicity
4. RED MAN syndrome (red neck and head after infusion)*

Front 32

Fosfomycin

Back 32

-cell wall inhibitor
-used for uncomplicated UTI
-3 g oral sachet
-category B
AE: Gi intolerance (diarrhea, nausease and dyspepsia)

Front 33

Inhibitors of protein synthesis

Back 33

1. Tetracyclines
2. Chloramphenicol (rarely used)
3. Macrolides (z-pack)
4. Clindamycin
5. Streptogramins
-Quinupristin-dalfopristin
6. linezolid

Front 34

Chloramphenicol

Back 34

MOA: binds to 50S of bacterial ribosome & inhibits protein synthesis
-broad spectrum
Clinical: Rarely used except in kids < 8 with severe rickettsial infections (RMSF) and pneumococcal PCN resistant meningitis with major hypersensitivity to PCNs
AE: Toxic- GRAY BABY SYNDROME; Bone Marrow suppression & aplastic anemia

Front 35

Tetracyclines

Back 35

MOA: bind to 30s unit
-Broad spectrum and includes G+(more) and G-, anaerobes, rickettsia, Borrelia, [Legionella, chlamydia, mycoplasma] --> (walking PNA)

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types of tetracyclines

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1. Demeclocycline (not used)
2. Tetracycline
3. Doxycycline (IV and PO) (impt)
4. Minocycline (impt)

Front 37

AE of tetracyclines

Back 37

1. GI symptoms
2. Photosenitivity (stay out of sun!)
3. Preg category D
4. Hepatotoxicity (more common in preg)
5. Nephrotoxicity (less w/doxy) (more when expired)
6. NOT to be used in kids <8
7. discoloration of teeth and abnl bone growth in young kids
8. Vestibular rxns: dizzy, vertigo (mino)

Front 38

Tetracyclines pharmacokinetics

Back 38

-best PO absorption w/doxy and mino
-do not take w/antacids, dairy or metal
Clinical:
1. Chlamydia infxs, 2. Mycoplasm, 3. Acne vulgaria, 4. Lyme disease (doxy), 5. RMSF

Front 39

Tygacil (tigecyclines)

Back 39

-IV
-similar to tetras but designed to overcome resistance problems
-approved for complicated intra-abd and skin infxs that need broad empirical coverage
-covers many gram + and gram - bacteria and anaerobes. good for MRSA

Front 40

Macrolides

Back 40

-erythromycin is prototype
-MOA: binds to 50s and prevents movement of tRNA alon ribosome
-erythromycin, azithromcyin, clarithromycin
-spectrum: primary gram +, also mycoplasma, legionella, chlamydia, H. pylori and Listeria (atypical PNAs); bordatella

Front 41

Macrolides pharm

Back 41

-Azithromycin has high concentrations and penetration with prolonged half life of 40-68 hours (z pack- 5 day course of abx)
-Clarithromycin and erythromycin potential for drug interactions

Front 42

Macrolides- clinical

Back 42

-Azithromycin used to treat chlamydia, mild and uncomplicated CAP, acute OM, pharyngitis in PCN allergic
-Clarithromycin --> CAP, MAC (mycobacterium avium complex-assoc with AIDS)
-Emcyin various forms

Front 43

Macrolides: AE and DI

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1. Epigastric distress
2. metallic taste
3. cholestatic hepatitis
4. E-mycin and clarithromycin can potentiate the effects of many drugs such as: Digoxin, Terfenabine, Warfarin

Front 44

Ketek (telithromycin)

Back 44

-Ketolide class of abx (similar to macrolides)
-PO
-MOA: binds to 2 diff sites on ribosome
-Used for: Community-acquired PNA due to Streptococcus PNA and other usual suspects in CAP
-AE: N/D, visual disturbances, drug interactions due to liver metabolism

Front 45

Clindamycin

Back 45

-MOA: binds to 50s
-PO and IV (short half life)
-Gram + anaerobics; staph, strep (esp is PCN allergic) and pneumococcus
-Tx of anaerobic and mixed infections (severe)
-Pelvic and abd. Abscesses, peritonitis, lung abscesses, aspiration pneumonia in combination with other agents such as aminoglycosides

Front 46

Clindamycin Pharm and AE

Back 46

-excellent penetration into abscesses and intracellularly
AE: DIARRHEA - pseudomembranous colitis

Front 47

Quinupristin-dalfopristin (Synecid)

Back 47

-IV
-binds to 50s
-tx for VRE and complicated infxs caused by highly resistant staph and strep
-$$ needs to be admin thru central line
-AE: infusion related to pan and phlebitis, drug interactions and arthralgias

Front 48

Linezolid (Zyvox)

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-last resort for VRE and severe infxs caused by resistant staph and strep
-MOA: prevents formation ribosome complex
-slightly more cost-effective than synecid; avail IV and PO
-AE: minor ARs, monitor plts

Front 49

Aminoglycosides

Back 49

-IV only
-MOA: binds to 30s
-Gentamycin, streptomycin tobramycin; amikacin
-SOA: GRAM - AEROBES
Tobromycin --> pseudomonas
Amikacin has broadest spectrum BIG GUN and may be used for infections resistant to gentamycin and tobramycin

Front 50

aminoglycosides pharm

Back 50

-IV, IM only
-fair penetration into brain
-excellent penetration in renal cortex
-synergy with beta lactams (do not mix in same tubing)
-postabx effect-work when the abx is no longer in system
-clinical: for severe gram - infxs (sepsis, PNA, UTIs) in combo with PCN

Front 51

Aminoglycosides AE

Back 51

1. ototoxicity (tinnitus, hearing loss;vertigo)
2. Nephrotoxicity- more common with gentamycin > 5 days (pts must be well hydrated!)
-serum drug concen monitored (high trough levels assoc with nephrotoxicity)

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Sulfonamides and trimethoprim (TMP)

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-Sulfonamides are used with TriMethoPrim (TMP) to produce synergistic blocking of folic acid synthesis (diagram)
Forms: oral absorbable, oral nonabsorbable (acts locally in GI), IV (cross into CSF), topical

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Sulfa and TMP drugs spectrum

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-some G+ and many G-, some protozoa like pneumocycstis (PNA in HIC pts) and toxoplasma

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Sulfa and TMP drugs spectrum clinical utility

Back 54

-topical agents for bacterial conjunctivitis and prevention of infx in burns
-PO and IV absorbable agents (sulfamethoxazole/Trimethoprim combination-Bactrum)
1. UTI and prostate infxs
2. PCP
3. Salmonella and shigella
4 chronic sinusitis

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sulfa drugs and TMP other agents

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-nonabsorbable --> sulfazalazine (local action on gut) (used for IBD)

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sulfa and TMP AE

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1. allergic rxns: rash, fever, SJS
2. N/V/D
3. photosensitive
4. granulocytopenia and thrombocytopenia
5. avoid G6PD pts
6. category C and contraindicated near end of pregnancy

Front 57

Fluoroquinolones

Back 57

MOA: inhibits DNA gyrase interfering with transcription and DNA synthesis
SOA: broad and varies b/t 4 generations; gram - > gram + aerobics incl peudomonas

Front 58

Fluoroquinolones 2nd gen

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-Ciprofloxacin with mostly G- including pseudomonas and little G+

Front 59

Fluoroquinolones 3rd gen

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-Levofloxacin, IV and oral
-gram neg and some gram post (strep and staph)

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Fluoroquinolones 4th gen

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-Gemifloxacin (factive)- strep, staphs and atypicals
-Moxifloxacin (avelox) IV, PO- broad w/anaerobic coverage

Front 61

clinical use of Fluoroquinolones

Back 61

1. UTI esp. Ciprofloxacin
2. Gonococcal infxs (inc resistance)
3. Community acquired PNA esp Levaquin
4. Bacillus anthracis
5. Intrabdominal infxs

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Fluoroquinolones pharm

Back 62

-PO = IV dosing
-mostly BID or qd
-renal elimination

Front 63

Fluoroquinolones AE

Back 63

1. C/in kids <18 due to possible damage to growing cartilage
2. C/I in preg
3. Tendonitis

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Metronidazole (Flagyl)

Back 64

-useful for parasitic and anaerobic infxs
-Gold standard PO, IV, for anaerobic
-amebae, Giardiasis, trichomoniasis, c.diff infxs
SE: disulfiram-like rxn w/alcohol, metallic taste, dark urine (harmless)

Front 65

Nitrofurantoin

Back 65

-for UTIs, PO
-MOA: broad activity against urinary pathogens
-? in preg
-AE: avoided in G6PD pts, pulmonary fibrosis in pts taking it everyday