Antibiotics, Antivirals, Antifungals

  1. Aztreonam
    Inhib's cell wall synth by binding to PBP... but B-lactamase resistant (and penicillinase-resistant, too, obv). Only works against Gram-neg rods. Good choice for people allergic to penicillin & cephalosporins, or renal insufficiency (so no aminoglycosides). Few SE's -- maybe GI.
  2. Cefoxitin
    2nd-gen cephalosporin: gram-pos cocci, gram-neg rods & cocci -- Neisseria, H.influenz, E.coli, Klebsiella, Enterobacter, Proteus, Serratia. Good for UTI's!
  3. Cefaclor, cefuroxime
    2nd-gen cephalosporin -- gram-pos cocci, gram-neg rods & cocci -- Neisseria, H.influenz, E.coli, Klebsiella, Enterobacter, Proteus, Serratia. (1st gen only did E.coli, Proteus, & Klebsiella -- PEcK.) Good for UTI's!
  4. Cephalexin
    1st-gen cephalosporin. Basically like amoxicillin: gram-pos cocci, some gram-neg rods -- PEcK. (But not Neisseria or H.influenzae -- would need to go up to a 2nd-gen for that.)
  5. Cefazolin
    1st-gen cephalosporin.
  6. Cefepime
    4th-gen cephalosporin. Great Pseudomonas & gram-pos coverage.
  7. Ceftazidime, ceftriaxone, cefotaxime
    3rd-gen cephalosporin, for serious infections. Pseudomonas, good at penetrating BBB for meningitis.
  8. Imipenem/cilastatin
    Imipenem = carbapenem: a B-lactam antibiotic that's B-lactamase resistant, works against G-pos cocci & G-neg rods including Pseudomonas! Signif CNS SE's (ex. seizures), so limit to serious infect's.

    Give cilastatin w/imipenem to make sure it stays in renal tubules longer (dec'd inactivation).
  9. GNATS: gentamicin, neomycin, amikacin, tobramycin, streptomycin
    Aminoglycosides. Cause mistranslation --> wrong AA's at 30S. Nephro- & oto-toxicity, Teratogens. Not anaerobes, b/c need O2 for uptake by bacterial cells.
  10. Doxycycline
    Tetracycline - prevents aminoacyl-tRNA transfer to 30S subunit. Bacteriostatic. For Weird Bacteria: Lyme disease (Borrelia), Rickettsia & Chlamydia (the 2 obligate intracellular), Mycoplasma, H.pylori, acne.

    SE's: GI, tooth discoloration/inhibition of bone growth (in kids), photosensitivity. "May get rid of acne, but interferes w/becoming a model."
  11. Azithromycin, clarithromycin, erythromycin
    Macrolides. Bind 50S subunit & block translocation. For major syndromes: UTI's/STD's, pneumonia. Covers all the major causes, so both gram-pos cocci & atypicals like Chlamydia, Mycoplasma, & Legionella (pneumonia). SE's: GI discomfort, rash, acute cholestatic hepatitis.
  12. Chloramphenicol
    Bacteriostatic, 50s (inhibits peptidyltransferase). The 3 major meningitis bacteria: S.pneumoniae, N.meningitidis, & H.influenzae (kids). SE's: gray-baby syndrome (in premature infants), anemia (dose-dependent), aplastic anemia (independent of dose)
  13. Clindamycin
    50S - blocks peptide bond formation. Anaerobes (vs. aminoglycosides, which won't do anaerobes at all!): Can't Breathe Air = clostridium, bacteroides (ex. bowel perforation), actinomyces. But toxicity = pseudomembranous colitis from C.diff overgrowth (since you're taking away the usual #1 gut bacterium, Bacteroides).
  14. Sulfonamides: Sulfamethoxazole, sulfisoxazole, sulfadiazine
    • Bacteriostatic. Inhibit nucleotide synthesis: inhibit folic acid synthesis by being a PABA analog. Both gram-pos & neg's. SE's: photosensitive, interstitial nephritis, displace other drugs from albumin (ex. warfarin), hemolysis in G-6-PD deficient ppl.
    • With sulfa allergies, some renal drugs are bad too: Acetazolamide (Carbonic anhydrase inhibitor), Furosemide, & thiazide diuretics.
  15. Trimethoprim
    Bacteriostatic - also inhibits folic acid synthesis (final step) -- use w/sulfonamides. Trimethoprim is the final step, b/c third comes after second.

    • UTI's, P.jiroveci pneumonia, Salmonella & Shigella.
    • SE's: TMP "Treats Marrow Poorly." Megaloblastic anemia, granulocyto- & leuko-penia. Everything low.
  16. Fluoroquinolones: -floxacin & nalidixic acid (for UTI's only)
    • Bactericidal; inhibit DNA topoisomerase II (gyrase). Mostly Gram-neg rods, GI & urinary tracts.
    • SE's: GI upset (go figure), tendon rupture & tendonitis, kids = leg cramps/myalgias, cartilage damage. (Don't use in pregnant women, either, b/c of the cartilage damage.)
  17. Metronidazole
    Damages DNA -- form toxic metabolites inside bacterial cell. Anaerobes, plus anti-protozoal. "Ride the Metro train": no alcohol (b/c bumpy ride), & metallic taste in mouth. Mutagenesis in fetus.
  18. Polymyxins
    "Mix up" cell membrane -- insert themselves & disrupt osmotic properties. (Act like detergents.) For resistant gram-neg infections. SE's: neurotoxicity & ATN.
  19. Isoniazid
    INH (injures neurons & hepatocytes). Dec'd synthesis of mycolic acids. Solo TB prophylaxis.
  20. Rifampin
    TB & meningitis prophylaxis; inhibits DNA-dependent RNA polymerase. SE's: "Ramps up" CYP450; orange body fluids.
  21. Amphotericin B
    "Tears up" fungal cell membranes - binds ergosterol --> creates pores --> electrolytes leak out. Systemic fungal infections; doesn't cross BBB, so intrathecal for meningitis. SE's: Shake & bake: fevers & chills, arrhythmia, anemia, nephrotoxicity (think ATN or azotemia), IV phlebitis.
  22. Nystatin
    Does same thing as Ampho B -- binds ergosterol & makes holes in fungal cell membrane -- but too strong to be used systemically. Use for oral/vaginal candidiasis or diaper rash.
  23. Azoles
    • Inhibit ergosterol synthesis. Ketoconazole = systemic fungal infect's, ex. pneumonia. Fluconazole = crosses BBB for cryptococcal meningitis (AIDS). Topical ones: clotrimazole, miconazole.
    • SE's: gynecomastia (inhibit hormone synthesis), CYP450 inhibition, fever/chills (Ampho B too).
  24. Flucytosine
    Converts itself to 5-FU, to mess up DNA synthesis. Systemic fungal infections (combine w/Ampho B). SE's: like chemo drugs -- nausea, vom, bone marrow suppression.
  25. Caspofungin
    The ABC's of caspofungin: Invasive aspergillosis, Inhibits B-glucan synthesis (cell wall) = caspofungin. SE's: GI upset, flushing.
  26. Griseofulvin
    Interferes w/microtubules (mitosis). Give orally, for superficial skin infections (tinea, ringworm). SE's: teratogenic & carcinogenic, inc'd CYP450 & warfarin metabolism.
  27. Acyclovir
    Antiviral, Guanosine analog (throw a "monkey wrench" into virus synthesis). To become active, it must be phosphorylated by thymidine kinase - so, only works for HSV & VZV (EBV too). SE's: usually none.
  28. Ganciclovir
    Same as acyclovir - guanosine analog to disrupt DNA synthesis - but this one doesn't require activation by viral thymidine kinase. More BM side effects -- low platelets, WBC's -- & renal toxicity. Used for CMV.
  29. Foscarnet
    Inhibits viral DNA polymerase. Doesn't need activation by viral thymidine kinase, so used for CMV or HSV when ganciclovir/acyclovir fail. Nephrotoxicity.
  30. Zanamivir, oseltamivir
    Neuraminidase inhibitors --> dec'd release of viral progeny. Influenza A & B.
  31. -navir drugs (saquinavir, ritonavir, indinavir, nelfinavir, amprenavir)
    HIV protease inhibitors -- so new virus particles can't mature. SE's: GI, hyperglycemia, lipodystrophy. (Think: Protein breakdown inhibited, and now the other 2 molecules can't be broken down properly -- sugars/glucose & lipids.)
  32. Nucleoside RT inhibitors = Zidovudine (AZT), didanosine, zalcitabine, stavudine, lamivudine, abacavir
    Non-nucleoside = nevirapine, efavirenz, delavirdine
    • Inhibit HIV's reverse transcriptase, so viral genome can't be incorporated into host DNA. SE's: bone marrow suppression/megaloblastic anemia, peripheral neuropathy, lactic acidosis (nucleosides).
    • Use zidovudine during pregnancy to reduce risk of fetal transmission.
  33. HAART (highly active antiretroviral therapy)
    Protease + RT inhibitors. When CD4 <500, or high viral load.
  34. Enfuvirtide
    Fusion inhibitor -- bind HIV's gp41 subunit so it can't fuse w/CD4 cells. SE's: subcutaneous rxns at injection site, hypersensitivity rxns, inc'd risk of bacterial pneumonia. Use w/other HIV drugs.
  35. Interferons
    • Interfere w/various stages of RNA & DNA synthesis; degrade mRNA, too (by inducing ribonuclease enzyme).
    • IFN-alpha = chronic Hep B & C, Kaposi's
    • IFN-beta = MS
    • IFN-gamma = NADPH oxidase deficiency

    SE's: Neutropenia
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Antibiotics, Antivirals, Antifungals
antibiotics for USMLE Step 1