Sulfonamides, Trimethoprim, and Fluoroquinolones

Question 1

Trimethoprim-sulfamethoxazole is established tobe effective against this opportunistic infections in AIDS patient

Answer 1

Toxoplasmosis

Question 2

A 65 year old woman has returned form acation abroad suffering from traveler’s diarrhea and her problem has not responed to antidiarrheal drugs, A pathogenic gram negative bacillus is supected. Whis is most likely to be effective in the treatment of this patient?

Answer 2

Ofloxacin

• The second generation fluoroquinolones are very effective in diarrhea

Question 3

Classifications of Fluoroquinolones

Answer 3

• First generation -derived from nalidixic acid
  
  • Norfloxacin
• Second generation - greater activity against gram (-) and gonococcus
  
  • Ciprofloxacin, ofloxacin
• third generation
  
  • Levofloxacibn, gemifloxacin, moxifloxacin
  • Respiratory quinolones

Question 4

Resistance of sulfonamides

Answer 4

Reduced intracellular uptake

Question 5

Resistance of fluoroquinolones

Answer 5

Decreased intacellular accumulation of the drug via the production of efflux pumps or changes in porin structure

Question 6

treatment protocol that is effective against both gonococci and chlamydia

Answer 6

Sulfamethoxazole or TMP-SMZ PLUS Azithromycin

Question 7

Gonococclal resistance to fluoroquinolones may oinvolve changes in __________

Answer 7

DNA gyrase

Question 8

Antacids can _____oral bioavailability of fluoroquinolones

Answer 8

Decrease

Question 9

Most fluoroquinolones undergo renal elimination and dosage should be modified with creatinine clearance ___________

Answer 9

<50 ml/min

Question 10

______has significant anti-inflammatory action ant its oral use result sin improvement in 50-75% of patients suffering from ulcerative colitis.

Answer 10

Sulfasalazine

Question 11

Most common adverse effect of sulfonamides

Answer 11

Skin rash

Question 12

_______ and _____ are drugs of choice in nocardiosis

Answer 12

Sulfadiazine and TMP-SMZ

Question 13

Drug that can cause tendinitis

Answer 13

Ciprofloxacin

Question 14

Supplementary folinic acid may prevent anemia in folate deficient persons who use this drug; it is a weak base achieving tissue levels similar to those in plasma

Answer 14

Trimethoprim

Question 15

Trimethoprim-sulfamethoxazole

Answer 15

Synergistic inhibition of folic acid synthesis. The combination is abctericidal by dequential blockade

Used in UTI, Respiratory, ear, and sinus infections. P. jirovecci pneumonia. toxoplasmosis. nocardiosis

Oral, IV. Renal clearance, half life- 10h

SE: Rash fever, bone marrow suppression, hyperkalemia. High incidence of adverse effects in AIDS patients

Question 16

Ciprofloxacin

Answer 16

Inhibits DNA replication via binding to DNA gyrase (Gram negative organism) and topoisomerase IV (gram positive organisms) bactericidal.

Effective in urogenital, GI tract and some respiratory infections. Activity versus gonococci rapidly declining. limited use in tuberculosis

Oral, IV. msotly renal clearance, half life 4h. Oral abdorption impaired by cations

SE: GI upsets, CNS effects (Dizziness, headache). Tenditis due to effects on cartilage (avoid in young children and preganncy). neurotoxicity

Question 17

Solubility of sulfonamides is decreased in _______ urine

Answer 17

Acidic

Question 18

Trimethoprim can reach high concentrations in _________ and _________ fluids

Answer 18

Prostatic and vaginal

Question 19

_________ can displace bilirubin from plasma proteins

Answer 19

Sulfonamides

Question 20

Mutations in the quinolone resistance-determining region of the _____ gene that encodes DNA gyrase is responsible for resistance in gonocci

Answer 20

gyrA

Question 21

Widest specturm of Flouroquinolones

Answer 21

Gemifloxacin and moxifloxacin