Inhibits Cell Wall Synthesis
|
Penicillins
(bactericidal: blocks cross linking via competitive inhibition of the transpeptidase enzyme)
|
Class/Mechanism | Drugs | Indications (**Drug of Choice) | Toxicity |
Penicillin | Penicillin G Aqueous penicillin G Procaine penicillin G Benzathine penicillin G Penicillin V | Strep. pyogenes (Grp.A)**
Step. agalactiae (Grp.B)** C. perfringens(Bacilli)** | Hypersensitivity reaction Hemolytic anemia |
Aminopenicillins | Ampicillin Amoxicillin | Above +
↑ Gram-negative:
E. faecalis**
E. Coli** | Above |
Penicillinase-resistant-penicillins | Methicillin Nafcillin Oxacillin Cloxacillin Dicloxacillin | Above + PCNase-producingStaph. aureus | Above + Interstitial nephritis |
Antipseudomonal penicillins | Carbenicillin Ticarcillin Piperacillin | Above + Pseudomonas aeruginosa** | Above |
Cephalosporins
(bactericidal: inhibits bacterial cell wall synthesis via competitive inhibition of the transpeptidase enzyme)
|
1st generation | Cefazolin Cephalexin | Staph. aureus** Staph. epidermidis** Some Gram-negatives: E. Coli Klebsiella | Allergic reaction Coombs-positive anemia (3%) |
2nd generation | Cefoxitin Cefaclor Cefuroxime | Above + ↑ Gram-negative | Allergic Reaction ETOH Disulfiram reaction |
3rd generation | Ceftriaxone Cefotaxime Ceftazidime Cefepime (4th generation) | Above + ↑ Gram-negative Pseudomonas | Allergic Reaction ETOH Disulfiram reaction |
Other Cell Wall Inhibitors
|
Vancomycin (bactericidal: disrupts peptioglycan cross-linkage) | Vancomycin | MRSA**
PCN/Ceph allegies**
S. aureus
S. epidermidis | Red man syndrome Nephrotoxicity Ototoxicity |
Beta-lactamase Inhibitors (bactericidal: blocking cross linking) | Clavulanic Acid Sulbactam Tazobactam | S aureus**S epidermis**E.Coli** Klebsiella** | Hypersensitivity Reaction Hemolytic anemia |
Carbapenems | Imipenem (+ cilastatin) Meropenem Doripenem Ertapenem | Broadest activity of any antibiotic (except MRSA, Mycoplasma) | |
Aztreonam | Aztreonam | Gram-negative rods Aerobes Hospital-acquired infections | |
Polymyxins | Polymyxin B Polymyxin E | Topical Gram-negative infections | |
Bacitracin | Bacitracin | Topical Gram-positive infections | |
Protein Synthesis Inhibition
|
Anti-30S ribosomal subunit
|
Aminoglycosides (bactericidal: irreversible binding to 30S) | Gentamicin Neomycin Amikacin Tobramycin Streptomycin | Aerobic Gram-negatives Enterobacteriaceae Pseudomonas | Nephrotoxicity Ototoxicity |
Tetracyclines (bacteriostatic: blocks tRNA) | Tetracycline Doxycycline Minocycline Demeclocycline | RickettsiaMycoplasmaSpirochetes (Lyme's disease) | Hepatotoxicity Tooth discoloration Impaired growth Avoid in children < 12 years of age |
Anti-50S ribosomal subunit
|
Macrolides(bacteriostatic: reversibly binds 50S) | Erythromycin Azithromycin Clarithromycin | Streptococcus H. influenzae Mycoplamsa pneumonia | Coumadin Interaction (cytochrome P450) |
Chloramphenicol(bacteriostatic) | Chloramphenicol | H influenzae Bacterial Meningitis Brain absces | Aplastic Anemia Gray Baby Syndrome |
Lincosamide (bacteriostatic: inhibits peptidyl transferase by interfering with amino acyl-tRNA complex) | Clindamycin | Bacteroides fragilis
S aureus
Coagulase-negative Staph & StrepExcellent Bone Penetration | Pseudomembranous colitis Hypersensitivity Reaction |
Linezolid (variable) | Linezolid | Resistant Gram-positives | |
Streptogramins | Quinupristin Dalfopristin | VRE GAS and S. aureus skin infections | |
DNA Synthesis Inhibitors
|
Fluoroquinolones
(bactericidal: inhibit DNA gyrase enzyme, inhibiting DNA synthesis)
|
1st generation | Nalidixic acid | Steptococcus MycoplasmaAerobic Gram + | PhototoxicityAchilles tendon rupture Impaired fracture healing |
2nd generation | Ciprofloxacin Norfloxacin Enoxacin Ofloxacin Levofloxacin | As Above +Pseudomonas | as above |
3rd generation | Gatifloxacin | As above + Gram-positives | as above |
4th generation | Moxifloxacin Gemifloxacin | As above + Gram-positives + anaerobes | as above |
Other DNA Inhibitors |
Metronidazole (bacteridical: metabolic biproducts disrupt DNA) | Metronidazole (Flagyl) | Anaerobics | Seizures Crebelar dysfunction ETOH disulfram reaction |
RNA Synthesis Inhibitors
|
Rifampin (bactericidal: inhibits RNA transcription by inhibiting RNA polymerase) | Rifampin | Staphylococcus Mycobacterium (TB) | Body fluid discoloration Hepatoxicity (with INH) |
Mycolic Acids Synthesis Inhibitors
|
Isoniazid | Isoniazidz | TB Latent TB | |
Folic acid Synthesis Inhibitors
|
Trimethoprim/Sulfonamides(bacteriostatic: inhibition with PABA) | Trimethoprim/Sulfamethoxazole (SMX) Sulfisoxazole Sulfadiazine | UTI organisms Proteus Enterobacter | Thrombocytopenia Avoid in third trimester of pregnancy |
Pyrimethamine | Pyrimethamine | Malaria T. gondii | |
antibiotics : classification & mechanism of action .
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