Protein Synthesis Inhibitors Flashcards
Gentamicin is used in combination with a _______ or _________ for treatment of serious enterococcus, staphylococcus, viridian group streptococcus
Penicillin or vancomycin
Azithromycin is administered ____hour(s) before or ____hour(s) after a meal
1 hour before; 2 hours after
Major way resistance is adapted to tetracyclines
Efflux pump
Aminoglycosides that cause misreading of mRNA
Bactericidal/Bacteriostatic?
Bactericidal
Action of Erythromycin
Binds to 50S r-RNA and prevents movement along m-RNA
Ototoxicity of aminoglycosides is enhanced by
Loop diuretics
Action of streptomycin
Changes shape of 30S r-RNA and causes m-RNA to be read incorrectly
This drug inhibits the activity of peptidyltransferase (static)
Chloramphenicol
Aminoglycosides, Tetracyclines, Spectinomycin, affect ___S component of ribosomes
30S
Aminoglycosides are composed of aminosugars linked through ____bonds
Glycosides
Aminoglycosides that interfere with the initiation complex of peptide formation.
Bactericidal/Bacteriostatic?
Bacteriostatic
3 mechanisms of resistance to aminoglycosides
Acetylation
Adenylation
Phosphorylation
2 aminoglycosides less vulnerable to inactivation enzymes
Netilmicin
Amikacin
Aminoglycosides pharmacokinetics
Water soluble, poor absorption in GIT, parenteral Administration requires
Amikacin has the same spectrum as
Gentamicin
Single daily dose of aminoglycosides is just as effective and less toxic due to
Ototoxicity and nephrotoxicity
Linezolid affects ____S component of ribosomes
50S
Spectinomycin can be used as an alternative treatment for _______. Single dose of __grams
Gonorrhea; 2g
Inhibits CYP450 enzymes (2)
Erythromycin and Clarithromycin
Azithromycin is acid _____(stable/Labile)
Stable
Tetracycline spectrum
S. N. HP. HD. B. V. C. R. M. BB. P. C&C
Streptococcus, Nesseria, H. Pylori, H. Ducrei, Brucella, V. Cholera, chlamydia, rickettsiae, mycoplasma, Borrelia burgdorferi, Protozoa, Anaerobes (C. Perfringens, C. Tetani)
Aminoglycosides exhibit ________dependent killing and a _______ effect where antibiotic activity persists beyond the time during which measurable drug is present
- Concentration-dependent
- Post antibiotic effect
Inhibits translocation of peptidyl-tRNA from acceptor to donor site (static)
Macrolides and clindamycin
Streptomycin spectrum (3)
Yersinia pestis
Francisella tularensis
Mycobacterium tuberculosis
Transport of aminoglycosides across the cytoplasmic membrane is enhanced by _____ or _____
Penicillin or vancomycin
Tertiary question: By what mechanism in protein inhibition is best to treat plague, tularemia, tuberculosis?
Change shape of 30S r-RNA to be read incorrectly
Action of chloramphenicol
Binds to 50S r-RNA and inhibits formation of peptide bond
Oral use of ____ for hepatic encephalopathy and in preparation for elective bowel surgery along with _____
Neomycin………Erythromycin
Aminoglycosides spectrum
Aerobic Gram - bacilli
Gram - bacteria that are Gentamicin-resistant usually are susceptible to _____
Amikacin
Amikacin is more potent against _______ than gentamicin
P. Aeruginosa
Second line drug for multi-drug resistant mycobacterium tuberculosis
Amikacin
Synergistic combination used in pseudomonal infections
Tobramycin + Piperacillin/ticarcillin
Most potent drug for P aeruginosa
Tobramycin
Using streptomycin in pregnancy can cause ___ in the newborn
Deafness
Complication of the GIT such as ____ can occur with use of tetracyclines.
Pseudomembranous colitis
Mechanism of Demeclocycline
Blocks ADH receptor in collecting ducts
2 aminoglycosides with limited topical use for minor soft-tissue infections
Neomycin and kanamycin
Neomycin and kanamycin often used in combo with _____ and _____
Bacitracin and polymyxin
Side effect of Demeclocycline
Diabetes insipidus
MG patients should take caution when taking _____ due to a _____
Aminoglycosides…..curare like effect
1st line therapy for chlamydial urogenital infections during pregnancy
Erythromycin 500 mg 6 hours for 7 days or single dose Azithromycin
Spectinomycin is a ______ antibiotic
Aminocyclitol antibiotic
Antidotes for aminoglycosides overdose
Neostigmine and calcium gluconates
Brucellosis treatment (2)
Gentamicin + doxycycline
Paromomycin spectrum
E. C. L. T.
Entamoeba histolytica
Cryptosporidium Parvum
Leishmaniasis
Tapeworms
Action of tetracycline
Interferes with the t-RNA anticodon reading of m-RNA codon by binding reversibly to 30S subunit
Doxycycline and tigecycline are eliminated mainly by
The liver
3 types of drugs that cause phototoxicity
Tetracyclines, sulfonamides, fluroquinolones
Azithromycin is most commonly used in (3)
CAP
Pharyngitis/skin infections
Chlamydia infections
Gentamicin spectrum
P. K. P. S. E. E.
P. Aeruginosa Klebsiella Proteus Serratia E. coli Enterobacter sp.
Nephrotoxicity of aminoglycosides is enhanced by: V A C C
Vancomycin
Amphotericin B
Cisplatin
Cyclosporine
Drug of choice for mycoplasma
Tetracycline
What macrolide is highly active against chlamydia?
Azithromycin
Endocarditis treatment using a protein synthesis inhibitor and_____
Streptomycin and penicillin
Drug of choice for Rickettsiae, spirochete, chlamydia
Doxycycline
Treatment of Chloroquine-resistant Malaria with_____
Tetracyclines
Only tetracycline that is therapeutically efficient to enter CSF
Minocycline
Result of tetracyclines on pregnant woman
Crosses placenta to cause bone deformities and tooth dysplasias
Renal complications from tetracyclines (2)
Fanconi syndrome; diabetes insipidus with Demeclocycline
What is the oral tetracycline of choice?
Doxycycline
Minocycline & Doxycycline pharmokinetics
Completely absorbed, impaired by cations, dairy foods and antacids, extremes in bile & urine
In renal disease, can doxycycline be administered? Why?
Yes- it is extremes in the bile
Which ways to administer tetracyclines? (IV, IM, oral)
IV and oral (not IM)
Administration and excretion of glycylcyclines: tigecycline?
Give slow IV infusion 30-60 min. Excreted in bile.
A patient was bitten by a tick, within ____hours, you may administer a single,______mg dose of ______
72 hours; 200 mg; doxycycline
Nausea, anorexia, diarrhea from tetracycline can be controlled by giving with food or _________.
Carboxymethylcellulose
What form of erythromycin causes cholestatic jaundice?
Estolate
Macrolides contain a ______ring to which ____________ are attached
Lactone ring; deoxy sugars
Macrolides are mainly
Bacteriostatic/bacteriocidal?
Bacteriostatic
Macrolides bind with _____________ in GIT and increases intestinal motility
Motilin receptors
Name a ketolide
Telithromycin
Name 4 macrolides
Erythromycin, Clarithromycin, Azithromycin, Roxithromycin
Clarithromycin and Azithromycin are better than Erythromycin because Erythromycin….
Poor bioavailability
Short half life
Poor GI tolerability
Limited H. Influenzae coverage
Adverse effects of macrolides (4)
Epigastric distress
GIT problems
Cholestatic jaundice
Prolong QT interval
Mechanism of action of Macrolides
Protein synthesis inhibitors irreversibly bind to 50S subunit and inhibit translocation step
Spectrum of macrolides
Gram +
Gram -
Atypical organisms
Spirochetes
Azithromycin is more active in ______ infections than Erythromycin
Respiratory
Erythromycin is acid _____(stable/labile) hence administered with ______
Labile; enteric coating
Does Erythromycin enter CSF?
No
Erythromycin and Clarithromycin inhibit metabolism of (5)
Theophylline Warfarin Cyclosporine Methylprednisolone Digoxin
Erythromycin is primarily excreted in ______
Bile
Azithromycin is excreted by _____
and is _____(more/less) tolerated in pregnancy than other macrolides
The kidney; more
Drug of choice for Diptheria
Erythromycin
Whooping cough should be treated with
Erythromycin
Azithromycin is more active against _______ than Clarithromycin and erythromycin
H. influenzae
Oral erythromycin base is sometimes combined with _____ or ______ for preoperative preparation of the colon
Neomycin or kanamycin
Clarithromycin is more active against _________(2) than erythromycin
Mycobacterium avian complex and H pylori
Are erythromycin-resistant strep and staph also resistant to Clarithromycin?
Yes