Class

5

ClassDrugDiseaseBiological Target / MechanismRoute of Admin.Side EffectsContraindicationsDrug Resistance

PenicillinsPenicillin G Gram (+) cocci

Gram (-) cocci (meningococci)

Gram (+) rods (Anthrax, Diphtheria)

Gram (-) rods (Bacteriodes)

Syphilis (prophylaxis & treatment)

Prophylax recurrent rheumatic fever

H. flu

enterococcal endocarditis

Leptospirosisinhibits transpepdidation that results in cross-linking of cell wall;

activates autolytic enzymes ( cell lysis (bactericidal)IV

(acid labile)

oral for newborns & elderly procaine syndrome, if given IV instead of IM

convulsions with massive dosesallergy & hypersensitivity inactivated by *-lactamases

MRSA: mutation of penicillin-binding protein

Penicillin V[same as Pen G]oral

Amoxicillin

(+ clavulanic acid = augmentin) Hemophilus

Gonorrheaoral (acid stable) Nausea

Vomiting

Diarrhea

Ampicillin Gram (+) rods (Listeria)

Gram (-) rods

(H. pylori)oral (acid stable) Nausea

Vomiting

Diarrhea

skin rashes

Ticarcillin Gram (-) rods, esp. pseudomonasno oral absorpion

Nafcillin staphIV (acid labile)penicillinase-resistant

*-lactamase InhibitorsClavulanic Acid Use with amoxicillin = augmentin

Sulbactam

Tazobactam

AntibioticsAntibiotics cont.ClassDrugDiseasesBiological Target / MechanismRoute of Admin.Side EffectsContraindicationsDrug Resistance

Sulfonamides and TrimethoprimSulfamethoxazole

UTIs (crystalluria not likely)

Nocordia infections (sulfa + minocycline)

Drug-resistant malaria & toxoplasmosis (sulfa + pyrimethamine)

Prevent recurrence of rheumatic fever if Pen G cannont be givencompetes with PABA for enzyme dihydropteroate synthetase and blocks folate synthesisoral route preferred

slow IV preferable to IM (irritates muscle tissue)Toxicity:

bone marrow depression crystalluria agranulocytosis & aplastic anemia in high-risk pts. Kernicterus in neonates Stevens-Johnson syndrome Pregnancy

Increases anticoagulant effect of oral anticoagulants (displaces them from albumin)

Synergistic effect with sulfonyl urea ( hypoglycemia

G6DP-deficient pts.: causes acute hemolytic anemia form of dihydropteroate with low affinity for sulfonamides

increased PABA production to overcome sulfa drugs

alternate pathways for nucleic acid synthesis

Trimethoprim acute UTIinhibits folate reduction (inhibits DHFR)oral route preferredbacteriostatic agents negated by pus, which contains thymidine & purines, so no need for folate

Co-Trimoxazole (Sulfamethoxazole

+ Trimethoprim) Pneumocystic carinii

Shigella & Salmonella (Quinolones are DOC)

UTI

Otitis media in children

Respiratory tract infection due to H. flu or strep

Gonococcal urethritis

Oralpharyngeal gonorrheasynergistic effectCombination reduces individual side effects

In AIDS pts.:

Fever

Rash

Leukoplakia

Folate deficiency

Hepatitispregnancy

Antibiotics cont.ClassDrugDiseasesBiological Target / MechanismRoute of Admin.Side EffectsDrug Resistance

Cephalosporins1st genCefalexin Gram (+) cocciinhibits transpepdidation that results in cross-linking (same as penicillins)

inactive against MRSA & enterococci (Strep Group D)oralsame as penicillininactivated by *-lactamases (same as penicillins)

Cefazolin Gram (+) cocci

E. coli

Klebsiella

Proteus

2nd genCefuroxime Gram (-)

Meningitis

Cefotetan Gram (-)

B. fragillis

3rd gen

(longest duration)Ceftriaxone Huge Gram (-) coverage

Meningitis

Haemophilus

Neisseria

Cefotaxime

Ceftazidime Huge Gram (-) coverage

Meningitis

Pseudomonas

4th gen

(more resistant to *-lactamases)Cefepime

P. aeruginosa

Enterobacteri a

S. aureus

S. pneumoniae

Haemophilus

Neisseria

Antibiotics cont.ClassDrugDiseasesBiological Target / MechanismRoute of Admin.Side EffectsContraindicationsDrug Resistance

Penems & MonobactamsAztreonam Substitute for amino-glycosides

DO2ndC:

Klebsiella

P. aeruginosa

Serratiabinds to PBP & inhibits cell wall synthesis;

synergistic with aminoglycosidesIM / IVNO renal toxicity (unlike amino-glycosides)Penicillin allergic pts. CAN tolerate this drugresistant to *-lactamases

ImipenemDOC:

Enterobacter

DO2ndC:

Staph infection

B. fragillis

P. aeruginosa Nausea

Vomiting

Diarrhea

Skin rash

Toxicity:

Seizures in pts. with renal failureallergy to penicillinresistant to most *-lactamases but not metallo-*-lactamases

Cilastatinuse with imipenemNOT an antibiotic;

inhibits renal dihydropeptidase I and thus prevents penem degredation

Tetracyclines, Chloramphenicol and AminoglycosidesTetracycline Rickettsia Chlamydia

Vibrio cholera

Plague

Lyme disease

Protozoa

Prophylax meningococcal meningitisbinds to 30S subunit and blocks binding of tRNA to A site on ribosome;bacteriostatic;bacteria have TC-uptake system and can concentrate TCsoral (not with food)Very Toxic: Retard bone growth in children (damage teeth, bone, nails) Suprainfection (treat with vancomycin)

Hepatic dysfunction (preggers)

Renal toxicitypregnancy (bone deformity, growth inhibition of fetus) efflux of tetracyclines out of bacteria plasmid-mediated resistance

resistance is wide-spread

Doxycycline prophylaxis for travelers diarrhea prostate infections

prophylax malaria in Chloroquine-resistant areasphoto-sensitization

Antibiotics cont.ClassDrugDiseasesBiological Target / MechanismRoute of Admin.Side EffectsContraindicationsDrug Resistance

Tetracyclines, Chloramphenicol and Aminoglycosidescont.Aminoglycosides[aerobic Gram (-) only]StreptomycinSevere infections only

Endocarditis caused by enterococci or viridans group

TB1) binds to P12 receptor protein on 30S subunit

2) blocks formation of [mRNA+formyl methionine+tRNA] complex

3) mRNA is misread

4) wrong aa inserted

bactericidalusually IM, rarely oral or IV (no adverse effects with oral, but only affect GI microbes)Nephrotoxic

Neuromuscular blockadeSerious Ototoxicity:

Hearing loss to fetus / newborn

Vertigo

Loss of vestibular organMyasthenia Gravis Deletion of P12 gene (chromosomal resistance)

Plasmid-dependent production of destructive enzymes

Mutant porins

Mutant 30S ribosome

NeomycinSevere infections only

Gram (-) enteric

In combo with *-lactams ( synergism, expands spectrum to Gram (+)

Pseudomonas (antipseudomonal penicillin)

Chronic UTI

E. coil or Klebsiella (with ampicillin, cephalosporin)

Gentamicin

Tobramycin

ChloramphenicolDO2ndC: Meningitis

TC diseases

Typhoid

Brain abscess caused by anaerobes

Eye infectionsbinds to 50S ribosome and inhibits transpeptidation (peptidyl transferase)Very Toxic: pancytopenia bone marrow disturbances

Gray Baby syndrome

deathG6PD-deficient pts. (hemolytic anemia), same as sulfa drugschloramphenicol acetyl transferase (from a plasmid gene) inactivates drug

Antibiotics cont.ClassDrugDiseasesBiological Target / MechanismRoute of Admin.Side EffectsContraindicationsDrug Resistance

Misc.Vancomycin Only Gram (+)

Meningitis caused by staph MRSA

C. diff suprainfectionprevents peptidoglycan construction (inhibits cell wall mucopeptide formation) Nephrotoxicity Ototoxicity

Thrombophlebitis

Diffuse flushing (red man syndrome)

Bacitracin Gram (+) cocci

Eye & skin infectioninterferes with regeneration of lipid carrier in peptidoglycan synthesis by blocking its dephosphorylation

QuinolonesCiprofloxacin UTIs caused by multidrug-resistant bacteria

Pseudomonas

Shigella

Salonella

E. coli

Helicobacter

Infections of soft tissue, bones, joints (not routine)

Intraabdominal & respiratory tract infections (not routine)

Gonococcal infections

Chlamydia

Prophylax travelers diarrheainhibits DNA gyraseoral GI disturbances

Suprainfection with streptococci & candidapts.