Misc. Abx Flashcards
Although tetracyclines are cross-reactive, ____________ is resistant to this because it is in the tetracyclin derivative category known as ____________.
*Tigecycline - Glycylcylins
What classes of microbials can tetracyclines be used against? (list some of the major targets) What 2 general conditions are they commonly used to treat?
- Gram-pos aerobes (*MSSA) - Gram-neg aerobes - Anaerobes - bacteroides spp. - Misc. bacteria. - legionella, chlamydophila, chlamydia, mycoplasma, ureaplasma, rickettsia (sketchy) - Often used for STI infections and dz’s caused by tick bites!
Does tigecyclin have a more or less broad spectrum of activity vs. tetracyclins? Which organism is tigecyline notably not active against?
- Broader * Pseudomonas
Besides being inactive vs. pseudomonas, what 2 other conditions does tigecycline NOT treat?
*UTIs and *bacteremia
*What type of meds are tetracyclines and glycylcyclines contraindicated with?
Di and tri-valent cations (they should even avoid dairy due to Ca2+) - Must separate administration by a few hours
What are the major serious side effects a/w tetracyclines/tigecycline?
- Severe N/V - Photosensitivity (should avoid sun)
What can occur if expired tetracyclines are prescribed?
Fanconi-like syndrome a/w renal failure
What drug acts synergistically w/sulfas?
Trimethoprim (also inhibits folate/purine synth pw but at a different enzyme–dihydrofolate reductase)
What is the precursor of purine synthesis? - How is it affected by purine synthesis pw inhibitors?
PABA - Builds up
What drugs are in the combination Bactrim?
Trimethoprim-Sulfamethoxazole (TMP-SMX)
Explain the target organisms (only) of the broad-spectrum antibiotic TMP-SMX (Bactrim).
gram-pos: *staph aureus (MRSA, CA-MRSA) Gram-neg: - Stenotrophomonas maltophilia. Other: - Pneumocystis carinii. Plus many more (broad spectrum)
When giving Bactrim, what lab level should be monitored and why?
CrCl (kidney function; eliminated partially by kidney)
*What are the (3) major clinical uses of TMP-SMX?
- Acute, chronic, or recurrent UTIs 2. Acute or chronic bacterial prostatitis 3. Skin infections due to CA-MRSA
What are the major adverse effects a/w TMP-SMX/Bactrim?
- Leukopenia - Thrombocytopenia - Rash/hypersensitvity - Renal impairment (crystaluria)
Are dose adjustments required in renal failure when giving chloramphenicol?
No, metabolized by liver