Sulfonamides

- SMX

-Sulfisoxazole

-Sulfadiazine

- Bactericidal

- Available in combination with TMP

- Spectrum of activity:

Gram (+) ; not Enterococci

Gram (-) ; limited to respiratory pathogens

Poor against atypicals or anaerobes

E.coli, Chlamydia, Nocardia, PCP, MRSA, Simple UTIs 

Toxicity: cross allergenicity, hyperkalemia, bone marrow suppression, Warfarin binding competition

Sulfonamides

Trimethoprim

- Bacteriostatic

- Often used in combination with sulfonamides as TMP-SMX

Spectrum of activity:

Only Staphylococcus and E.coli

Recurrent UTIs, Shigella, Salmonella, PCP, Ocular infections

Toxicity: Bone marrow suppression resulting in megaloblastic anemia, leukopenia, granulocytopenia

Clindamycin

Chloramphenicol

Linezolid

Aminoglycosides

Macrolides

Tetracyclines

Tigecycline

(CCLAMTT)

Mechanism of resistance:

Chloramphenicol

- Bacteriostatic

- Binds to 50s ribosomal subunit

- Excellent CNS penetration

Spectrum of activity:

Gram (+) ; MRSA and some VRE

Gram (-) ; common respiratory pathogens

Most anaerobes and atypicals

Meningitis (SHiN), Resistant Gram (+)

Toxicity: SEVERE, anemia, Grey Baby syndrome, aplastic anemia

Mechanism of resistance:

Aminoglycosides

Aminoglycosides

- Gentamicin

- Streptomycin

- Neomycin

- Bactericidal

- Bind to the 30s ribosomal subunit, misreading of genetic code

- Require OXYGEN for uptake

Spectrum of activity:

Gram (-)

Limited Gram (+) but synergistic when combined with β-lactam

Part of TB therapy

NO ANAEROBIC/ATYPICAL activity

GRAM (-) infections

Used in combination to treat Gram (+)

Toxicity: Nephrotoxicity, Ototoxicity, Teratogen (NOT)

Mechanism of resistance:

Tetracyclines

Production of efflux proteins(increased efflux)

Production of ribosomal protection proteins (decreased uptake)

Tetracyclines

- Tetracycline

- Doxycycline

- Bacteriostatic

- Doxycycline can be used in patients with renal failure

- DO NOT take with dairy produces, antacids, vitamins/mineral supplements because they prevent absorption in the gut 

Spectrum of activity:

Gram (+) ; some MRSA

Gram (-) ; common respiratory pathogens

Oral anaerobes and atypicals

Rickettsia, Chlamydia, Syphilis, Borrelia, H.pylori, M.pneumoniae, B.anthracis

Toxicity: Photosensitivity, do not take with chelating agents, GI distress, inhibition of bone growth in children

- Ribosomal 30s subunit inhibition

- Similar to tetracyclines

Spectrum of activity:

Gram (+)

Gram (-)

Anaerobes

SSTIs, Intra-abdominal infections

Toxicity: hyperemesis

Mechanism of resistance:

Clindamycin

- Bacteriostatic

- Binds to 50s ribosomal subunit

Spectrum of activity:

Anaerobes

Gram (+); some MRSA and enterococci

Anaerobes = Bacteroides fragilis, Clostridium perfringens

abscesses, acne, PID

Toxicity: can cause C.diff overgrowth

- Bacteriostatic against Staph, Entero

- Bactericidal against Strep

- Prevents tRNA binding to A site of ribosome

Spectrum of activity:

Gram (+)

Some Gram (-)

Gram (+) and VRE infections

Toxicity: hypertension, serotonin syndrome

Mechanism of resistance:

Macrolides

Macrolides

- Clarithromycin

-Azithromycin

- Erythromycin

- Bacteriostatic

- Binds to 50s ribosomal subunit

Spectrum of activity:

(SHAM)

Strep, Staph, Enterococci

H. pylori

Atypicals and anaerobes

Mycobacteria

Atypical pneumonias (Chlamydia, Legionella, Mycoplasma),

Gram (+) bacteria, Neisseria

Toxicity: GI upset, potency, hepatic clearance, CYP inhibitors, can prolong QTc interval

Ketolides

- Telithromycin

- 2nd generation macrolide

- Able to bind at more sites than macrolides

- Active against resistant strains

Spectrum of activity:

Respiratory tract infections

Atypical bacteria

Atypical bacteria, Macrolide resistant strains

Toxicity: highly toxic, same as macrolides

Penicillins

Cephalosporins

Carbapenems

Monobactams

General considerations:

Penicillins

- Bactericidal

- No Atypical Activity

- Inactivation of degrading enzymes (Penicillin-resistant)

- Alterations in PBP enzyme targets (MRSA)

- Well-tolerated

- May need dose reductions due to renal elimination

(exc. Nafcillin, Oxacillin)

Natural Penicillins

- Penicillin V

- Penicillin G

- Procaine

- Benzathine

- Beta-lactam

- Method of resistance is the production of Beta-Lactamases

Spectrum of activity:

Gram (+) aerobes ; Strep and Entero

Treponema pallidium

Strep and Syphilis, Meningitis, Endocarditis

Aminopenicillins

- Ampicillin

-Amoxicillin

- Unasyn

- Augmentin

- Combined with Beta-Lactamase inhibitors, they become more effective

Spectrum of activity:

Gram (+) ; Strep, Enterococci

Limited Gram (-)

Combined: Improved Gram (+), more Gram (-) and some anaerobic activity

SSTIs, Otitis, Lyme disease (2nd line tx)

Anti-Staphylococcal Penicillins

- Nafcillin, Oxacillin

- Cloxacillin, Dicloxacillin

Spectrum of Activity:

Limited to only Staph and Streptococci

Osteomyelitis, SSTIs

Toxicity: Some hepatic elimination, mild elevations in liver function enzymes

Anti-Pseudomonal Penicillins

- Piperacillin

- Piperacillin/Tazobactam

- Less Gram (+) activity

Spectrum of activity:

Gram (-)

Anaerobes

Addition of the beta-lactamase inhibitor improves activity

Broad-spectrum empiris or targeted therapy of nosocomial infections

Clinical considerations:

Cephalosporins

ALL cephalosporins have NO activity against enterococci

MOST cephalosporins have NO activity against anaerobes

MOST need to have doses reduced due to renal metabolism

Beta-lactam rash considerations

1st Generation Cephalosporins

- Cefazolin

- Cephalexin

Spectrum of activity:

Gram (+) ; no enterococci or MRSA

SSTIs, Tonsilitis, UTIs

2nd Generation Cephalosporins

- Cefuroxime

- Cefotetan

- Cefoxitin

Spectrum of activity:

Gram (+)

Some beta-lactamase Gram (-)

UTIs, sinusitis, Lyme Disease (2nd line tx)

3rd Generation Cephalosporins

- Ceftazidime

- Ceftriaxone

Spectrum of activity:

Gram (-) ; except Pseudomonas

Ceftazidime has Pseudomonal activity

less Gram (+) activity

All of the activity of other cephalosporins

+

Meningitis, UTIs, chronic Lyme disease