Anti-microbial Drugs Flashcards
(28 cards)
What is the difference between bacteriostatic and bacteriocidal antibiotics?
Bacteriostatic = arrest growth
Bacteriocidal = kill bacteria
List the two groups of drugs that inhibit bacterial cell wall synthesis?
penicilins ; cephalosporins
Which drug is best for treating syphilis?
Benzathine Penicillin G
Which drugs are effective against Pseudomonas Aeruginosa?
Antipseudomonal Penicillins:
Piperacillin ; Carbenicillin
What is the action of Clavulanic Acid?
it inhibits penicillinases like Beta-Lactamase that can open the beta-lactam ring of the penicillin rendering it ineffective.
What drug is paired with Clavulanic Acid to make augmentin?
Amoxicillin
What is the first-line drug in the Tx of gonorrhea?
[also treats meningitis in children bc of its effectiveness against hemophyllus influenzae]
third generation Cephalosporins:
Ceftriaxone
Which Inhibitors of Protein Synthesis bind to the 30s ribosomal subunit? Which inhibitors bid to the 50s ribosomal subunit?
30s: Aminoglycosides, tetracylcines ;
50s: macrolides, clindamycin
What are the U/E of Aminoglycosides?
nephrotoxicity ; ototoxicity ; neruomuscular toxicity
ototoxicity involves both vestibular and cochlear divisions of CN VIII
narrow therapeutic index
What is the synergistic effect of penicillins and aminoglycosides?
penicillins cause cell wall abnormalities that allow the aminoglycosides to gain entry into the bacteria.
Which aminoglycoside is used orally in hepatic coma to decrease the coliform flora to decrease production of ammonia?
neomycin
what are the U/E of tetracyclines?
staining of teeth ; retardation of bone growth ; photosensitivity
not recommended for pregnant women, children or patients w renal impairment.
Which inhibitors of protein synthesis are most effective in the Tx of rickettsiae ; chlamydia ; mycoplasm ; borrelia infections?
tetracyclines
Which inhibitors of protein synthesis are used in Tx of patients w mycoplasm pneumonia ; legionnaires’ disease ; chlamydia ; diphtheria and pertussis?
macrolides
What macrolides are the drug of choice for the Tx of pneumonia caused by legionella and mycoplasma?
erythromycin ; azithromycin
What are the U/E of Chloramphenicol?
bone marrow depression ; aplastic anemia usually fatal ; gray baby syndrome
What is the drug of choice for anaerobic GI infections?
clindamycin
What drug is associated w pseudomembranous colitis?
clindamycin -
kills all bacteria except Clostridum Deficile which easily proliferates to cause pseudomembranous colitis
what is MOA of Trimethoprim-Sulfamethoxazole (Cotrimoxazole)?
-it’s a Folate antagonist, bacteria must produce it’s own folic acid, this drug prevents folic acid synthesis
[Sulfonamides are structurally similar to PABA and block the incorporation of PABA into dihydrofolate acid. Trimethoprim prevents reduction of dihydrofolate to tetrahydrofolate by inhibiting the enzyme dihydrofolate reductase.]
-most commonly used drug in this group; used for UTI and Pneumocystitis carinii pneumonia, etc.
MOA and u/e of Fluroquinolones? list important drugs of this group?
MOA - inhibit DNA gyrase and topoisomerase IV, and thereby inhibit bacterial DNA replication.
u/e - damage to growing cartilage in animals, not recommended for children
drugs: norfloxacin, ciprofloxacin, levofloxacin
use of Metronidazole?
- inhibits DNA synthesis
- drug of choice for trichomoniasis (STD), Amebiasis (Dysentery), and Giardiasis (Dysentery)
- also drug of choice for antibiotic-associated enterocolitis (pseudomembranous colitis) caused by Clostrudium deficille
why are anti-tubercular drugs given as combination therapy?
to prevent emergence of resistant strains
what is the MOA, use, and the u/e of Isoniazid? how can adverse affect be prevented?
MOA - inhibits synthesis of mycolic acids in cell wall
used as First-Line drug for tx tuberculosis
u/e: hepatotoxicity and peripheral neuropathy
-neuropathy can be prevented by prescribing Vit B6 along with Isoniazid
what are effects of Rifampin on liver?
[this is anti-tuberculosis drug]
this drug is metabolized in the liver and is potent inducer of cytochrome P-450 enzymes
