L26: Tetracyclines/Macrolides Flashcards
Which of the following is NOT a Macrolides?
A. Erythromycin
B. Clarithromycin
C. Azithromycin
D. Tetracycline
D. Tetracycline
Tigecycline belongs to which group?
A. Ketolides
B. Macrolides
C. Tetracyclines
D. Glycylcyclines
D. Glycylcyclines
Which of the following is targeted by tetracyclines and aminoglycosides?
A. 30 S
B. 50 S
A. 30 S
Tetracyclines are considered
_____, meaning host
immune system required to
finish off infection
A. bacteriostatic
B. bacteriocytic
C. bacteriocidal
A. bacteriostatic
How to tetracyclines enter bacteria??
Passive diffusion / Active transport
True or False: Tetracyclines reversibly bind 30S to block binding of next aminoacyl-tRNA to the ribosome
True
What are the two primary uses of tetracyclines?
Note: broad spectrum
1) Acne
2) Chlamydial infections
Why are tetracyclines not usually a drug of choice for many gram (+) aerobic infections??
Resistance with Staphylococci, Streptococci and
some Pneumococci
Which gram (-) bacteria / Anaerobes are resistant to tetracycline?
Gram (-)
- Pseudomonas
- Enterobacteriaceae
Anaerobes
B. fragilis
True or False: Brucella, Vibrio Cholera can be treated with tetracycline
True
Minocycline microspheres is a type of tetracycline that is used to treat ___ disease
peridontal
Why are tetracyclines minimally used?
Because large number of bacterial strains are resistant
Which conditions does doxy primarily used to treat?
1) Skin/Soft Tissue infections (MRSA)
2) Chlamydia
________: tetracycline-resistant strains; skin and abdominal infections; Proteus and Pseudomonas are resistant
A. Tigecycline
B. Tetracycline
C. Clarithromycin
D. Doxycycline
A. Tigecycline
True or False: Tetracycline is concentration + time dependent killing (maximize AUC)
True
True or False: Tetracycline crosses placental barrier (pregnancy category D); excreted in breast milk
True
Doxycycline and tigecycline are eliminated by _____
mechanisms - important for patients with kidney failure or co-
administered nephrotoxic drugs
non-renal
AE associated with Tetracyclines?
1) Teeth
- discoloration
- enamel dysplasia in teeth
- reduced growth/deformities
2) Superinfections - C. diff
3) Skin sensitivity to sunlight
4) Nephrotoxicity
- Fanconi syndrome can result from use of degraded tetracycline
- do not dose with dairy
True or False: Under no circumstances should expired tetracycline be used
True
What are two ways to avoid drug resistance (tetracyclines)?
1) Impaired drug influx or increased
efflux via active membrane
transporters
2) Expression of proteins that interfere
with drug binding to 30S ribosomal
subunit
