Respiratory Pharmacology

• Phenylephrine and oxymetazoline are direct-acting sypathomimetics.
• Oxymetazoline is used as a topical decongestant because of its ability to promote constriction of the vessels in the nasal mucosa and conjunctiva. 
• Ephedrine is a noncatechol phenylisopropylamine, it has a high bioavailability and a relatively long duration of action
• Pseudoephedrine is an ephedrine enatiomer.
• Folate synthesis inhibitors: sulfonamides and trimethoprim
• Cell wall synthesis inhibitors: Beta-lactams, vancomycin, penicillin, Fosfomycin, etc.
• Rifampin is an RNA polymerase inhibitor.
• Fluroquinolone is a DNA gyrase inhibitor.
• Polymyxin, ketoconazole, and amphotericin are cell membrane inhibitors.
• Protein syntehsis inhibitors include macrolides, chloramphenicol, clindamycin, etc.
• Minimal Inhibitory Concentration (MIC): lower drug concentration that inhibits bacterial growth. 
• Post-Antibiotic Effect: After antibacterial drug removal evidence of persistent effect on bacterial growth.
• The basic molecular mechanism that mediate bacterial resistance to antibiotics

  • Drug inactivation
  • Target modification
  • Concentration reduction
  • Bypassing
• SMX inhibits dihydropteroate synthase.
• TMP inhibits dihydropteroate reductase.
• TMP and SMX are bacteriostatic alone.
• TMP and SMX are bactericidal together.
• Topoisomerase II is a site where gram negative bacteria are more vulnerable.
• Topoisomerase IV is a site where gram positive bacteria are more vulnerable.
• Empiric therapy is used when there is a risk with waiting to find a specific pathogen.
• Definitive therapy is used when there is a specific pathogen identified.