Antibiotics

Injury to the Plasma Membrane

•Polymyxin B (Gram negatives)

–Topical

–Combined with bacitracin and neomycin (broad spectrum) in over- the-counter preparation

Competitive Antagonistic

Antibiotics

• Isoniazid - Inhibits mycolic acid synthesis

• Sulfonamides - Inhibit folic acid biosynthesis

Competitive Inhibitors

Figure 5.7

Antifungal Drugs

•Fungi are eukaryotes

•Have unique sterols in their cell walls

•Pathogenic fungi are often outside the body

Antiviral Drugs

•Viruses are composed of nucleic acid, protein capsid, and host membrane containing virus proteins

•Viruses live inside host cells and use many host enzymes

•Some viruses have unique enzymes for DNA/RNA synthesis or protein cutting in virus assembly

Figure 20.16a

Antiviral Drugs

Nucleoside and Nucleotide Analogs

Figure 20.16a

Analogs Block DNA Synthesis

Figure 20.16b, c

Antiviral Drugs

Enzyme Inhibitors

•Inhibit assembly

–Indinavir (HIV)

•Inhibit attachment

–Zanamivir (Influenza)

•Inhibit uncoating

–Amantadine (Influenza)