Antibiotics 1

1. SULFONAMIDE

   Anmerkungen:

   • Synergy with trimethoprim leads to bacteriocidal effect
   1. Competitively inhibits dihydropteroate synthetase
   2. Pregnancy, nephrotox, hemolysis

      Anmerkungen:

      • Cross placenta
2. TRIMETHOPRIM

   Anmerkungen:

   • Synergy with sulfonamide often make bacteriocidal effect
   1. Inhibits dihydrofolate reductase
3. Bacteriostatic

1. PENICILLINS, CEPHALOSPORINS
   1. Block transpeptidase rxn

      Anmerkungen:

      • by binding penicillin binding proteins
   2. Very safe!

      Anmerkungen:

      • We don't have these proteins in our cell walls
   3. Penicillin G - neurotox

      Anmerkungen:

      • From non-specific irritation
   4. Least toxic, most allergenic
2. VANCOMYCIN, BACITRACIN
   1. Block early steps in synthesis
   2. Toxic to kidneys
3. CYCLOSERINE
   1. Blocks alanine racemase

1. POLYMYXINS
   1. Form pores
   2. Bind phosphatidyl ethanolamine-rich areas of membrane
   3. Highly toxic to kidneys

      Anmerkungen:

      • We have phosphatidyl ethanolamine in our membranes Why these are toxic
   4. CHOLISTINS

      Anmerkungen:

      • Currently being made

1. Aminoglycosides
   1. Bind to 30S
   2. Bacteriocidal
   3. STREPTOMYCIN
      1. Pregnancy

         Anmerkungen:

         • 8th cranial nerve damage Skeletal defects
   4. Nephrotox, neurotox

      Anmerkungen:

      • Neurotox in infants
2. TETRACYCLINES
   1. Blocks tRNA binding 30S
   2. Bacteriostatic
   3. Pregnancy, liver tox, neurotox

      Anmerkungen:

      • Hypoplasia of fetal teeth & bones in fetus Cataracts in fetus Neurotox in infants
3. CHLORAMPHENICOL, ERYTHROMYCIN, CLINDAMYCIN
   1. Bind 50S
   2. Inhibit chain elongation
   3. CHLOR - pregnancy, inhibits P450, toxic to marrow/hemolysis

      Anmerkungen:

      • Crosses placenta
   4. CHLOR - phenytoin, coumadin

      Anmerkungen:

      • Inhibits their breakdown

1. RIFAMPIN
   1. Inhibits DNA-dependent RNA polymerase
      1. Inhibits RNA synthesis
   2. Birth control pills

      Anmerkungen:

      • Enhances breakdown
2. Quinolones
   1. CIPROFLOXACIN
      1. Blocks DNA gyrase
3. METRONIDAZOLE
   1. Inhibits nucleic acid synthesis

1. GOOD
   1. Sulfonamide + trimethoprim
   2. Isoniazid + rifampin
      1. Treat TB
   3. Penicillin + aminoglycoside

      Anmerkungen:

      • Penicillin stops cell wall formation Allows aminoglycosides to get inside
      1. Mixed infections
      2. Prophylaxis
   4. Trimethoprim + sulfamethoxazole
      1. Treat Pneumocystis carinii pneumonia

         Anmerkungen:

         • In people with AIDS
   5. Bactericidal + bactericidal or bacteriostatic + bacteriostatic
2. BAD
   1. Bactericidal + bacteriostatic
   2. Penicillin + tetracycline

1. GI

   Anmerkungen:

   • C. diff -> fatal colitis Nausea & vomiting
2. Liver tox
   1. Isoniazid

Anmerkungen:

• Antibiotics act as haptens (give immune response when attached to large molecule)