Term
| How do tetracyclines work? |
|
Definition
| Reversibly block the 30s ribosome to prevent protein synthesis |
|
|
Term
| What are two ways tetracyclines enter susceptible bacteria? |
|
Definition
| Simple diffusion AND active transport |
|
|
Term
| What 3 drugs are effective against resistant bacterial strains because they are not a substrate for the efflux pump in resistance? |
|
Definition
| Doxycycline, minocycline, tigecycline |
|
|
Term
| What are the 3 mechanisms by which bacteria convey resistance to tetracycline? |
|
Definition
1- impaired influx or enhanced efflux by an active transport pump
2- ribosome protection
3- enzymatic inactivation of the drugs |
|
|
Term
| What drug is effective even against the Tet (A) efflux-expressing gram negative strains that have resistance to older tetracyclines? |
|
Definition
|
|
Term
Tet(K) in staph confers resistance to what drugs?
What drugs does it not confer resistance to? |
|
Definition
Resistance to Tetracyclines
Not to doxycycline, minocycline, or tigecycline |
|
|
Term
Tet(K) ribosomal protection expressed by gram positive strains confers resistance to what drugs?
What drugs does it not confer resistance to? |
|
Definition
Resistance to Tetracyclines
Not to doxycycline, minocycline, or tigecycline |
|
|
Term
Which of the tetracycline family drugs is absorbed most readily? Least readily?
Is given IV? |
|
Definition
Most readily= Doxycycline and Minocycline
Least readily= chlortetracycline
Tigecycline is given IV |
|
|
Term
| What impairs absorption of tetracyclines except for doxycycline and minocycline? |
|
Definition
| Food in the GI tract impairs absorption |
|
|
Term
| Which tetracycline attains high concentrations in saliva and tears making it useful for eradication of the meningococcal carrier state? |
|
Definition
|
|
Term
| How are tetracyclines excreted? |
|
Definition
| Mainly in urine and in bile with enterohepatic circulation |
|
|
Term
| What two tetracyclines are eliminated via non-renal mechanisms and don't require does adjustments for renal failure? |
|
Definition
| Doxycycline and tigecycline |
|
|
Term
| What tetracyclines are short acting? |
|
Definition
| COT- Chlortetracycline, Oxytetracycline, Tetracycline |
|
|
Term
| What tetracyclines are intermediate acting? |
|
Definition
| Demeclocycline, Methacycline |
|
|
Term
| What tetracyclines are long acting? |
|
Definition
|
|
Term
| Which tetracycline has a half life of 36 hours? |
|
Definition
|
|
Term
| For what infections are tetracyclines most useful? |
|
Definition
| T-SCRAM- Trachoma, Spirochetes, Chlamydia, Rikettsiae, Anthrax, Mycoplasma Pneumonia |
|
|
Term
| How are tetracyclines used to treat H. Pylori-induced ulcers? |
|
Definition
| In combination with a proton-pump inhibitor and other agents |
|
|
Term
| What are tetracyclines combined with to treat plague, tularemia, and brucellosis? |
|
Definition
|
|
Term
| For what protozoa are tetracyclines sometimes given? |
|
Definition
Entamoeba Histolytica
Plasmodium Falciparum |
|
|
Term
| What tetracycline may be used in some ADH secreting tumors? |
|
Definition
|
|
Term
| What broad-spectrum tetracycline is useful against coagulase negative staph, staph aureus, and methicillin resistant strains? |
|
Definition
|
|
Term
| Proteus and pseudomonas aeruginosa are resistant to what tetracycline? |
|
Definition
|
|
Term
| What do tetracyclines do to the kidneys? |
|
Definition
| Cause nitrogen retention and (except for doxycycline and tigecycline) tend to accumulate in renal insufficiency |
|
|
Term
| Which tetracycline is especially likely to cause photosensitivity? |
|
Definition
|
|
Term
| What is the mechanism of action of Clindamycin? |
|
Definition
| Binds EXCLUSIVELY to the 50S ribosome and inhibits protein synthesis |
|
|
Term
| What bacterium are usually susceptible to clindamycin? |
|
Definition
Streptococci, staphylococci, and pneumococci
Bacteroides are usually susceptible |
|
|
Term
| What bacterium are resistant to clindamycin? |
|
Definition
| Enterococci and gram negative aerobic organisms |
|
|
Term
| What is the mechanism of resistance to clindamycin? |
|
Definition
-mutation of ribosomal receptor site
-constitutive expression of methylase causing modification of receptors
-enzymatic inactivation of clindamycin |
|
|
Term
| Gram negative aerobes are intrinsically resistant to what drug due to the poor permeability of their outer cell wall? |
|
Definition
|
|
Term
| What drug penetrates well into abscesses and concentrates in phagocytic cells via active transport? |
|
Definition
|
|
Term
| How is clindamycin used to treat penetrating wounds to the abdomen or gut? |
|
Definition
| In combination with cephalosporin or aminoglycosides |
|
|
Term
| What drug is used for septic abortion? |
|
Definition
|
|
Term
| What drug is used for pelvic abscesses? |
|
Definition
|
|
Term
| What drug is used in aspiration pneumonia? |
|
Definition
|
|
Term
| What drug is used for prophylaxis against endocarditis in patients with valvular heart diseases? |
|
Definition
|
|
Term
| Clindamycin is used with what drug as an effective alternative to trimethoprim-sulfamethozazole against moderate to severe pneumocystis jirovei in AIDS patients? |
|
Definition
|
|
Term
| What drug is combined with clindamycin to treat AIDS-related toxoplasmosis of the brain? |
|
Definition
|
|
Term
| Severe diarrhea and pseudomembranous colitis as a result of clindamycin administration are most likely caused by what bug? |
|
Definition
|
|
Term
| What is the mechanism of action of chloramphenicol? |
|
Definition
|
|
Term
| What drug is active against rickettsia but NOT against chlamydia? |
|
Definition
|
|
Term
| Haemophilus influenza is highly susceptible to: |
|
Definition
|
|
Term
| N. Meningitis is highly susceptible to: |
|
Definition
|
|
Term
| What is the mechanism of resistance to chloramphenicol? |
|
Definition
| Production of chloramphenicol acyl transferase, a plasmid-encoded enzyme |
|
|
Term
| What drug is conjugated in the liver (glucuronic acid) and eliminated in the urine? (probably a bunch, I know, but specific to this lecture) |
|
Definition
|
|
Term
| When must the dose of chloramphenicol be reduced? |
|
Definition
| In hepatic insufficiency, but NOT in renal insufficiency |
|
|
Term
| What drug causes bone marrow disturbances/ decreased production of red blood cells? |
|
Definition
|
|
Term
| What drug causes aplastic anemia? |
|
Definition
|
|
Term
| What drug causes GRAY BABY SYNDROME? |
|
Definition
|
|
Term
| What is gray baby syndrome? |
|
Definition
Vomiting, flaccidity, hypothermia, gray color shock and collapse
-caused by chloramphenicol |
|
|
Term
| What drugs are metabolized a slower rate in the presence of chloramphenicol? |
|
Definition
Phenytoin, tolbutamide, chlorpropamide, and warfarin
-causes increase in half-life |
|
|
Term
| Chloramphenicol can antagonize the effects of what drugs? |
|
Definition
| Penicillin and aminoglycosides |
|
|
Term
| What do we use PREFERENTIALLY to treat Chlamydial Conjunctivitis? |
|
Definition
|
|
Term
| What do we use to treat malaria and why? |
|
Definition
| Doxycycline- fewer effect on GI |
|
|
Term
| How do we treat Rocky Mountain Spotted Fever? (first line, second line) |
|
Definition
| Tetracyclines- first line; Chloramphenicol- second line |
|
|
Term
| How do we treat haemophilus influenza? |
|
Definition
|
|
Term
| What drug penetrates the CNS well? |
|
Definition
|
|
