robbypowell's version from 2016-09-19 23:25

Tetracyclines, Aminoglycosides & Sulfonamides (abandon all hope, ye who enter here)

Question Answer
Tetracyclines have a ______ ring structure and are primarily for veterinarian useFour ring
Tetracyclines are bacterio-_______bacterio-STATIC ((only multiplying organisms are affected
List the tetracyclines in order from most to least activeMino- > Doxy- > Tetra- > Oxytetra- (all cycline suffixes)
Are tetracyclines narrow or broad spectrum?BROAD (GM+/-, anaerobes, aerobes, rickettsia, chlamydia)
Are tetracyclines used in dentistry?NO (because they are bacterioSTATIC) (why are we learning about them then?)
Tetracyclines enter cells in what two ways?Passive diffusion OR Energy-dependent transport
Tetracyclines inhibit ______ synthesis by binding to what?Protein synt; 30s subunit of ribosomes
Because tetracyclines act on the target that they do... what cannot bind to the target (thus inhibiting protein synthesis)Amino Acyl t-RNA (cannot bind to 30s subunit of ribosomes)
How is resistance to tetracycline transmitted by bacteria?via PLASMID
what are the 3 ways that microbes can mechanistically be resistant to Tetracyclines?Decreased uptake, Decreased ribosomal access, Enzymatic inactivation
T/F: Tetracycline dosing varies with drug (in the 30-100% range) but are all readily absorbed in the GI tractTrue
Rings in tetracycline/doxycycline chelate ____ with ___ and decreased bioavailabilityCa; Milk
Dairy products, Calcium, bismuth and _______ _______ can inhibit absorption of tetracyclinesAluminum hydroxide
Tetracycline affects milk of breastfeeding bother how?Chelates out all Calcium (no calcium for baby)
Chelation of ______ causes browned developing teethCalcium
Does tetracycline cross placenta?Yes (don't all antibiotics?)
Tetracycline is contraindicated in children under ____ years of age or people with severe _____ disease8 yo; Liver
Tetracycline causes ______-sensitivityPhoto-sensitivity (easily sunburned)
T/F: Tetracycline can be detected in bodily secretions of patients that use themTrue (breastmilk as an example)
Minocycline is high especially in what two secretions? excreted how?high in tears & saliva; excreted urine & bile (bile --> poopoo)
Half life of tetracyclines is lower for patients on what two types of meds, due to microsomal enzyme induction?Phenytoin & Barbiturates
What is the dosage of DOXY and MINO cyclines?100mg q12h and then 50mg b.i.d. (don't take until 2 hrs after dairy)
Tetracycline is especially used for what STI?Chlamydia
Tetracycline is especially used for what bone tick-borne disease?Rickettsia
Tetracycline is most commonly used in adolescents to treat what?Acne
T/F: Tetracyclines were originally not used for orofacial infections due to bacteriostatic nature and chance of resistanceTrue (however this is being reconsidered because of resistances to other AB's)
Side effects of Tetracyclines include: ______ burning, ______sensitivity, ______ discoloration in developing children, and hepatotoxicity (also disruption of normal oral and gut flora)EPIGASTRIC burning; PHOTOsensitivity; TOOTH discoloration
T/F: Tetracycline can be toxic to kidneys in patients with kidney diseasesTrue
____ syndrome: diabetes like symptoms from taking expired tetracyclinesFanconi Syndrome
What class other than tetracyclines also targets the 30s ribosomal subunit?Aminoglycosides (e.g. streptomycin)
What antibiotic class has side effects of ototoxicity (ear), nephrotoxicity (kidney), and neuromuscular blockade (muscle relaxant effect)?Aminoglycosides
Are aminoglycosides used orally?No (i guess parenterally)
Are ahminoglycosides useful for treating systemic infections?NO (stays local to tissues)
What are the 3 side effects of Aminoglycosides (streptomycin e.g.)ototoxicity, nephrotoxicity, & neuromuscular blockade
This class of antibiotics is widely used against common infections and synergistically with TrimethoprimSulfonamides
Sulfonamides are commonly used synergistically with ______Trimethoprim
list the 3 aminoglycosides that we've been told aboutSTREPTOmycin, GENTAmicin, & NEOmycin
Which Aminoglycoside is given as an injection to treat Tuberculosis?STREPTAmycin
Which Aminoglycoside can be given as an injection or topically?GENTAmicin
Which Aminoglycoside is taken orally and used to treat GI infections?NEOmycin
Do Aminoglycosides have high or low bio-availability?LOW, (which is why they stay local)
Aminoglycosides have a synergistic effect with ______ antibiotics and are most effective against gram ____ bacteriaB-Lactam; Gram Neg
Sulfonamides are a structural analogue of _____ which is precursor of _____ _____.... this is how they interfere with its synthesisPABA (para-amino benzoic acid); Folic Acid
Do mammals create our own folic acid?No (this is why sulfonamides don't affect us, but do microbes)
T/F: many people are allergic to SulfonamidesTrue (sulfur drug allergy?)
T/F: Sulfonamide allergies are rareFalse (many people are allergic)
Sulfonamides are mainly used to treat ____ ____ infections and _______ infectionsUrinary tract; Respiratory
Sulfonamides inhibit what specific enzyme?dihyropterate synthase (converts PABA to dihydrofolic acid)
Sulfonamides affects synthesis of what type of nucleic acid?Purine (PABA necessary for microbial purine synthesis)
T/F: Sulfonamides inhibit DNA synthesis in bacteriaTrue
T/F: Sulfonamides inhibit DNA synthesis in patientsFalse (we don't manufacture folic acid with same pathway)
Septra is a combo of what two drugs?sulfamethoxazole + trimethoprim
4 causes of sulfonamide resistanceCan't take up drug, overproduction of PABA (so ineffective), exogenous source of PABA, altered enzyme that lowers sulfonamide binding (dihyropterate synthase is the enzyme)
Are sulfonamides widely distributed throughout the body?Yes
Sulfonamides are readily absorbed via the _____ and _____ _____stomach; small intestine
Sulfonamides are excreted how?by kidney
What antibiotics are often given to HIV patients because it has higher plasma protein binding and lasts longer in body?Sulfonamides
What class antibiotics often given for "traveler's diarrhea"?Sulfonamides
Trimethoprim inhibits what enzyme?Dihydrofolic acid reductase (double whammy when given with Sulfonamides)
Bacitracin, Neomycin, and polymxin beta are triple antibiotics given via what route?TOPICAL (these are topical antibiotics)
Mupirocin (bactroban) is given via what route?TOPICAL cream
Two drugs for UTI that release ammonia and formaldehyde in urine causing acidic orange urinenitrofurantoin (macrobid) & methenamine
What is antibiotic drug for treating leprosy?Dapsone
You're friend just got leprosy... how cool! what will you give him?Dapsone (Daps, son!)
Which of these drugs is NOT used to treat tuberculosis: isoniazid, rifampin, pyrazinamide, etambutol, streptomycin, dapsoneDapsone is not (the other 5 are: SPIRE)

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