Pharm II Test 1 Flashcards
Which antibiotics are not eliminated by non-renal mechanisms?
Think D-CRIMES
Doxycycline
Clindamycin
Rifampin –> inducer of P450 (hepatotox)
Isoniazid –> genetic polymorph (hepatotox)
Metronidazole –>interacts c etoh
Erythromycin-like (macrolides) - inhibits P450
Sulfonamides - risk of renal crystalluria
Selective toxicity: inhibit pathway found in bacteria but not in humans
Folate metabolism
Selective Toxicity: Pathway exists in both, difference in enzyme structure.
- protein synthesis –> bact have 30s and 50s units
- Nucleic acid synthesis - DNA gyrase vs topoisomerase (humans)
Selective Toxicity: Macromolecular structure does not exist in humans.
Cell wall synthesis –peptidoglycan
Selective toxicity: macromolecular structure differs between microbes and humans.
Cell membrane: Ergosterol (fungi) vs cholesterol (human)
Modes of resistance
- natural
- escape
- acquired resistance
Types of acquired resistance
- Spontaneous mutational (chromosomal) resistance
- Plasmid mediated (MDR gene)
How to minimize abx resistance?
- use only when needed
- select based on susceptibility tests
- use adequate concentration / duration
Bactericidal
- inhibit cell wall synthesis
- disrupt cell membrane function
- interfere with DNA function or synthesis
Bacteriostatic
- inhibition of protein synthesis
- inhibition of intermediary metabolic pathways
Common gram + cocci
Strep
Staph
Enterococci
common gram - cocci
Neisseria
M. catarrhalis
Common gram - Rods
E.coli
Pseudomonas aeruginosa
H. influenzae
Common gram + rods
Listeria
Anaerobes, gram + rods
Clostridium difficile
H. pylori
Anaerobes, gram - rods
Bacteroides fragilis
Common atypicals
Chlamydia
Mycoplasma
Rickettsia
Advantages of Oral administation
- ease
- patient acceptance
- lower cost
Disadvantages of oral admin
- GI upset b/c alteration of normal intestinal flora
- incomplete or lack of absorption
- not ok for NPO pts
Which drug has beneficial accumulation in the bone?
Clindamycin
Osteomyelitis
Which drug class has beneficial accumulation into pulmonary cells?
Macrolides
URI or pneumonia
Which drug class has beneficial accumulation into gingival crevicular fluid and sebum?
Tetracyclines
Periodontitis
acne
Which drug has beneficial accumulation into urine?
Nitrofurantoin
UTIs
Which drug class harmfully accumulates in cells of inner ear and renal brush borders?
Aminoglycosides
- ototoxicity
- nephrotoxicity
Which drug class harmfully binds Ca++ in developing bone and teeth?
Tetracyclines
- abnormal bone growth
- tooth discoloration
