Antibiotics 1

1. SULFONAMIDE

   Annotations:

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

      Annotations:

      • Cross placenta
2. TRIMETHOPRIM

   Annotations:

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

1. PENICILLINS, CEPHALOSPORINS
   1. Block transpeptidase rxn

      Annotations:

      • by binding penicillin binding proteins
   2. Very safe!

      Annotations:

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

      Annotations:

      • 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

      Annotations:

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

      Annotations:

      • Currently being made

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

         Annotations:

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

      Annotations:

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

      Annotations:

      • 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

      Annotations:

      • Crosses placenta
   4. CHLOR - phenytoin, coumadin

      Annotations:

      • Inhibits their breakdown

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

      Annotations:

      • 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

      Annotations:

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

         Annotations:

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

1. GI

   Annotations:

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

Annotations:

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