Naturally occurring agents produced when cells are infected by virus. IFN-alpha and IFN-beta trigger nonspecific reaction. Uninfected cells make antiviral proteins to protect themselves.
- Various ones prevent virus by entering host cell.
- Example: amatadine prevents uncoating of Influenza A virus
- Various ones specific for select protease. Inhibits proper formation of "working" proteins.
- Binds to microtubules and prevents spindle apparatus formation-inhibitor of microtubules(mitosis).
- High penetration into keratin. Used for fungal infections of the skin, nails, ringworm, athletes foot.
- Inhibits DNA gyrase, the enzyme needed for uncoiling bacterial DNA so it can be replicated-inhibits nucleic acid synthesis
- example: ciprofloxacin (Cipro)
Binds to the enzyme RNA polymerase which is needed to synthesize RNA-inhibit nucleic acid synthesis
- Mimic the natural occurring nucleosides. mistakenly incorporated into DNA-inhibit nucleic acid synthesis
- Virus must be actively replicating
Blocks different reaction in folic acid synthesis-interuption of metabolic pathways
Competitively inhibits PABA needed for folic acid synthesis so organism cant make nucleic acids-interuption of metabolic pathways
Antisense nucleic acids
A strand of nucleic acid complimentary to mRNA, blocks attachment of ribosomal subunits-inhibitor of protien synthesis
- Binds to 50S ribosome which blocks ribosome movement and prevents reading of mRNA-inhibitor of protien synthesis
- Examples include: erythromycin, azithromycin (zithromax) and clarithromycin (biaxin)
- Block the docking of the tRNA-AA to the A site of the 30S subunit-inhibitor of protien synthesis.
- Discoloration off teeth and stunts bone growth in young children.
- Blocks reading of mRNA by binding to 30S subunit of ribosome-inhibitor of protien synthesis.
- Poorly absorbed orally, given IV, narrow theraputic range, otic and nephrotoxic
- Prevents peptide bond formation between adjacent amino acids because binds to 50S subunit-inhibitors of protien synthesis
- In bone marrow prevents incorporation of hemoglobin into RBC=aplastic anemia
Change membrane permeability by inhibiting synthesis of ergosterol. Blocks the enzyme lanosterol a-demethylase-disrupts plasma membrane
- Attaches to ergosterol and changes membrane permeability by creating pores in the membrane-disrupts plasma membrane
- High concentration can target cholesterol in human cells leading to nephrotoxicity
- Changes membrane permeability by attaching to phospholipid (phosphatidylethanolamine) in the plasma membrane-disrupts plasma membrane
- Also targets eukaryotic cells and can cause nephrotoxicity
Inhibit synthesis of beta-glucan component of cell wall by inhibiting the enzyme 1,3 beta-glucan synthase-inhibits cell wall synthesis
- Forms a complex within bacteria that blocks the enzyme, fatty acid synthase. This prevents mycolic acid production-inhibits cell wall synthesis
- Drug of choice however used with other antimicrobials to prevent rapid resistance
- inhibits transport of NAG and NAM to PTG growing points outside of plasma membrane-inhibits cell wall
- Only used IV, Known as "mississippi mud" otic and nephrotoxicity
- Inhibits transport of NAM to cell wall by blocking the transporter, bactoprenol-inhibits cell wall synthesis
- Renal toxicity reatricts use to topical agents (triple antibiotic ointment)
- Competitvely blocks crosslinking of NAG/NAM subunits-inhibits cell wall
- Bacteria developed lactamases that destroy beta-lactam ring