Protein Synthesis Inhibitors (Tetracyclines ) Flashcards
What are Protein Synthesis Inhibitors?
- Tetracyclines
- Aminoglycosides
3.Macrolides &Ketolides
4.Chloramphenicol
5.Clindamycin
6.Oxazolidinones
Tetracycline class include :
-Minocycline
-Doxycycline
-Demeclocycline
-Tetracycline
MOA for tetracyclines :
-Rversible binding with 30S subunit of bacterial Ribosome preventing binding of tRNA with mRNA
Tetracyclines are ……………………. Antibiotic , and are effective for …….. , ……….., ………….,…………..and ……….. .
Bacteriostatic / Gram + , Gram - , protozoa , spirochetes and atypical.
Tetracycline is prescribed in
Peptic ulcer disease
Doxycycline is prescribed in : ( 6 cases )
- Acne
- Cholera
- Rocky Mountain Spotted Fever
- Lyme disease
- Chlamydia
- Mycoplasma Pneumonia
MOR for Tetracycline :
1) Efflux pump
2) Enzymatic inactivation of the drug
3) Interfering with binding to ribosomes
……………. Is not a common mechanism of resistance of tetracyclines
Cross-Resistance
How are tetracyclines taken?
Orally
Rate of absorption
Tetracycline are adequately absorbed but it is decreased if it is administered with dairy ( high cations )
Why is the rate of absorption of tetracyclines decreased when it is administered with cations ?
Because they form non- absorbable chelates.
Where are tetracyclines distributed ?
1) body fluids including CSF
2) bind to tissues undergoing calcification ( bone ,teeth )
3) Cross placenta and deposit in fatal bones during pregnancy
How are tetracyclines eliminated ?
They are eliminated unchanged in urine
How are doxycyclines eliminated ?
In bile /feces
What are the adverse effects of tetracyclines ?
1) Pseudotumor cerebri
2) Vestibular Dysfunction
3) Effects on calcified tissues
4) Gastric discomfort
5) Hepatotoxicity
6) Phototoxicity