Pharm Sulfonamides, Trimethoprim, And Fluoroquinolones

Front 1

Questions: What is true about ciproflxacin is accurate?

Back 1

Tendinitis and tendon rupture may occur during treatment.

Front 2

Questions: Supplementary folinic acid may prevent anemia in folate-deficient persons who use this drug, a weak base that achieves tissue levels similar to those in plasma?

Back 2

Trimethoprim, which is a weak base.

Fluoroquinolones and sulfonamides are acidic compounds and its high lipid solubility at blood pH allows for penetration into prostatic and vaginal fluid.

Front 3

Questions: What statement about sulfonamides is accurate?

Back 3

Sulfonamides inhibit dihydropteroate synthase. Example of applying this concept: Dysfunction of the basal ganglia may occur in the newborn if sulfonamides are administered late in pregnancy.

It is a bacteriostatic drug.

Front 4

Questions: The combination of trimethoprim and sulfamethoxazole is effective against which opportunistic infection in the AIDS PT?

Back 4

Toxoplasmosis (it is effective against some protozoans)

Front 5

Questions: A 24 year old woman has returned from a vacation abroad suffering from traveler's diarrhea, and her problem has not responded to antidiarrheal drugs. A pathogenic gram-negative bacillus is suspected. Which drug is most likely to be effective in the treatment of this PT?

Back 5

Levofloxacin (fluoroquinolones are very effective in diarrhea caused by bacterial pathogens).

Front 6

Questions: What statement about the clinical use of sulfonamides is true?

Back 6

Resistant bacterial strains may have decreased intracellular accumulation of sulfonamides; sulfonamides have activity against C. trachomatis and can be used topically for the treatment of chlamydia infections of the eye; sulfonamide resistance can occur in some strains of bacteria because of increased production of PABA.

Front 7

Questions: A 31 year old man has gonorrhea. He has no drug allergies, but a few years ago acute hemolysis followed use of an antimalarial drug. The physician is concerned that the PT has an accompnaying urethritis caused by C trachomatis, although no cultures or enzyme tests have been performed. Which of the following drugs is most likely to be effective against both gonococci and C. trachomatis in this PT?

Back 7

Ofloxacin and other fluoroquinolones (however, norfloxacin is the least active fluoroquinolone) are effective against both. Cefixime is effective only against gonorrhea.

Front 8

Questions: What statement about the fluoroquinolones is accuate?

Back 8

Antacids decrease oral bioavailability of fluoroquinolones. Neither hepatic nor renal dysfunction is contraindicated with the use of fluoroquinolones (most undergo renal elimination and dosage should be modified with creatinine clearance <50 mL/min). Fluoroquinolones should not be used first with children due to effects on cartilage. Gonococcal resistance to fluorquinolones may involve changes in DNA gyrase.

Front 9

Questions: A 55 year old man complains of periodic bouts of diarrhea with lower abdominal cramping and intermittent rectal bleeding. Seen in the clinic, he appears well nourished, with blood pressure in the normal range. Examination reveals moderate abdominal pain and tenderness. His current medications are limited to loperamide for his diarrhea. Signmoidoscopy reveals mucosal edema, friability, and some pus. Laboratory findings include mild anemia and decreased serum albumin. Microbiologic examination via stool cultures and mucosal biopsies do not reveal any evidence for bacterial, amebic, or cytomegalovirus involvement. A preliminary diagnosis is made of mild to moderate ulcerative colitis. The most appropriate drug to use in this PT is?

Back 9

Sulfasalazine. Without evidence to microbial cause of colitis, a drug that reduces inflammation is indicated. Sulfasalazine is also used for its anti-inflammatory effects in rheumatoid arthritis.

Front 10

Questions: What statement about the combination of trimethoprim plus sulfamethoxazole (TMP-SMX) is true?

Back 10

It is an alternative to ampicillin in the treatment of listeriosis; effective for treatment of pneumonia caused by Pneumocystis jiroveci (not community-acquired pneumonia); fever and pancytopenia occur frequently when these drugs are given to AIDS PTs; produces sequential blockade of folic acid synthesis.

Front 11

Questions: What adverse effect is most likely to occur with sulfonamides?

Back 11

Most common is skin rash from hypersensitivity. CNS and hematuria occur less frequently. Kernicterus is rate is Sulfonamides are avoided in the third trimester.

Front 12

Questions: What drug is effective in the treatment of nocardiosis and, in combination with pyrimethamine, is prophylactic against Pneumoncystis jiroveci infections in AIDS PTs?

Back 12

Sulfadiazine and TMP-SMX are the DOC for nocardiosis.

Front 13

Sulfonamides and trimethoprim interfere with?

Back 13

Folic acid synthesis.

Front 14

Fluoroquinolones inhibit what?

Back 14

Microbial nucleic acid metabolism.

Front 15

Sulfamethoxazole is a structural analog of what, and what is the significance of this?

Back 15

PABA (para-aminobenzoic acid), a dihydrofolic acid precursor. High levels of PABA analogue competitively inhibits dihydropteroate synthase, the enzyme needed for folic acid synthesis.

Human cells do not make TH4 (tetrahydrofolate). TH4 gives up carbons to form purines and other metabolic building blocks.

Front 16

Sulfamethoxazole, is it bacteriostatic or bactericidial?

Back 16

Bacteriostatic

Front 17

Trimethoprim is a selective inhibitor of?

Back 17

Bacterial dihydrofolate reductase, thereby, inhibiting folic acid synthesis.

Front 18

Trimethoprim-sulfamethoxazole (TMP-SMX) is effective against?

Back 18

Gram negative and Gram positive, Chlamydia trachomatis, Nocardia

TMP-SMX
T: respiratory Tree (Streptococcus pneumoniae and Haemophilus influenzae); otitis media, sinusitis, bronchitis, and pneumonia

M: Mouth (GI tract) for gram-negative for diarrhea (Shigella, Salmonella, Enterobacter, Kelbsiella, E. coli)

P: Pee (genitourinary tract) for UTI, prostatitis, urethritis caused by Enterics (E. coli)

SMX (Syndrome): AIDS, for prophylactic intervention of Pneumonocystis carinii pneumonia.

protozoans (Toxoplasma gondii and Isospora belli)

Front 19

TMP-SMX is the DOC for?

Back 19

Nocardia and Pneumocystis jiroveci pneumonia.

Shigella, Salmonella, UTIs

Front 20

What are the side effects of TMP-SMX?

Back 20

Steven-johnson syndrome, hemolytic anemia, kernicterus in newborns, bone marrow suppression.

Note: administer folic acid to compensate for megaloblastic anemia, leukopenia, and granulocytopenia.

Allergic reactions

Front 21

Ciprofloxacin, belongs to what class of drugs?

Back 21

Fluoroquinolones.

Front 22

What are the fluoroquinolones and what is the single quinolone? MOA?

Back 22

-floxacin (e.g., ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin; nalidixic acid is the quinolone (is rapidly excreted and hardly used.

Inhibits bacterial DNA topoisomerase II (DNA gyrase), inducing DNA strand breakage and cell death in gram negative organisms.

Front 23

DNA gyrase (topoisomerase II) performs?

What does topoisomerase IV perform?

Back 23

Induces negative supercoiling of dsDNA that balances the positive supercoiling of DNA replication, acting as a "swivel" to prevent damage to DNA strand.

Bacterial topisomerase initiating decatenation, the mechanism by which 2 daughter DNA molecules are separated at the conclusion of DNA replication.

Front 24

Fluorquinolones, are they bacteriostatic or bactericidal?

Back 24

Bactericidal

Front 25

Fluoroquinolones are effective against?

Back 25

Gram negatives very well!!--given with abdominal surgery? Widely used for respiratory tract, skin, and soft tissue infections.

Diarrhea via enteric organisms--except anaerobes!!

UTI

Chronic bone infections (osteomyelitis) (Pseudomonas, S. aureus, or Enterobacteriaceae).

Faculatative intracellular organisms (Legionella, Brucella, Salmonella, and atypical Mycobacteria).

Front 26

What are the SE of fluoroquinolones?

Back 26

Ciprofloxacin: Tendonitis, and tendon rupture in adults (avoid in children and in pregnancy)

Other fluoroquinolones: same as ciprofloxacin, but also QTc prolongation--caution in class IA and III antiarrhytmics.

Front 27

Fluoroquinolones are contraindicated in?

Back 27

Pregnant woman and children due to damage to growing cartilage.

Front 28

Fluoroquinolone achieves high levels in the?

Back 28

Stool, kidneys, penetrate well into bone and prostate. AND, achieve high intracellular levels.

Excreted in the bile and reabsorbed in the intestine and then excreted via the kidney.

Front 29

Trimethoprim, looks like what, and what is the significance of this?

Back 29

Dihydrofolate reductase. Once TH4 gives up a carbon, it becomes TH2 (dihydrofolate) and must be reduced back to TH4 by dihydrofolate reductase.

Front 30

TMP-SMX is excreted in what, and what is the significance of this?

Back 30

In the urine; therefore, it is good for UTIs.

Front 31

Combination of trimethoprim plus sulfamethoxazole, is bactericidal or bacteriostatic?

Back 31

Bactericidal.

Front 32

What is triple sulfa used for?

Back 32

Due to solubility limitation, a combination of 3 separate sulfonamides are used to reduce the likelihood that any one drug will precipitate.

Front 33

How are sulfonamides classified?

Back 33

Sulfisoxazole: short acting

Sulfamethoxazole: intermediate

Sulfadoxine: long-acting

Front 34

Sulfonamides are active against?

Back 34

Chlamydia and Nocardia.

UTI: triple sulfa, sulfisoxazole

Ocular infections: topical sulfacetamide

Burn: topical mafenide, silver sulfadiazine

Ulcerative colitis, rheumatoid arthrits: oral sulfasalazine

Toxoplasmosis: oral sulfadizine plus pyrimethamine plus folinic acid.

Front 35

Specific examples of fluoroquinolone usage: norfloxacin and ofloxacin; levoflxacin, gatifloxacin, and moxifloxacin

Back 35

Norfloxacin and ofloxacin: mainly for UTIs

Levofloxacin and moxifloxacin: are "respiratory" fluoroquinolones with enhanced activity against gram-positive cocci and atypicals (chlamydia, legionella, mycoplasma).

Front 36

Gemifloxacin and moxifloxcin usage?

Back 36

Have the widest spectrum: includes both gam-positive and gram negative, and some anaerobic bacteria and atypical pneumonia agents.

Front 37

Sulfa drug allergies?

Back 37

Sulfasalazine, sulfonylureas, thiazide diuretics, acetazolamide, or furosemide.