60 Questions
What is the mechanism of action of sulfonamides in bacteria?
Substituting PABA needed for folate formation
Why are side chains useful in sulfonamides?
To aid in the formation of folate required for protein synthesis
What cellular events are initiated by osteoclastic bone resorption and followed by osteoblastic bone formation?
Formation of new bone tissue
Which organisms are susceptible to sulfonamides' inhibition of dihydropteroate synthase?
Both gram-positive and gram-negative bacteria
Why is Pseudomonas aeruginosa resistant to sulfonamide antibiotics?
It has an intrinsic mechanism that prevents sulfonamide action
What do sulfonamides inhibit to disrupt the production of folate?
Dihydropteroate synthase
In which pH conditions are sulfonamides more soluble?
Alkaline pH
What is the mechanism of action of pyrimethamine when combined with sulfadoxine?
Inhibiting dihydrofolate reductase
Which condition is Sulfasalazine commonly used for?
Ulcerative colitis
How are sulfonamides and their inactive metabolites mainly excreted?
Urine
What is the role of sodium sulfacetamide in topical treatment?
Treating bacterial conjunctivitis
In which conditions is mafenide acetate used topically?
Burn sites
Which sulfonamide is preferred over mafenide acetate for preventing infection of burn wounds?
Silver sulfadiazine
What is the drug of choice for infections like Pneumocystis jiroveci pneumonia?
Sulfamethoxazole
What can cause sulfonamide resistance due to overproduction of PABA?
Mutations
What is the first-line therapy for the treatment of Acute Toxoplasmosis?
Sulfadiazine + Pyrimethamine
Which drug combination blocks sequential steps in the folate synthesis pathway?
Sulfadoxine + Pyrimethamine
Which oral agent is used as a 2nd line treatment for Malaria?
Pyrimethamine (Fansidar)
Which topical agent is effective in the treatment of bacterial conjunctivitis?
Sodium sulfacetamide
In which condition is Sulfasalazine widely used?
Ulcerative colitis
What is a particularly serious and potentially fatal type of skin and mucous membrane eruption associated with sulfonamide use?
Stevens-Johnson syndrome
Which adverse effect of sulfonamides can lead to kidney failure and potentially be fatal?
Hematuria
What is the recommended treatment for crystalluria caused by sulfonamides?
Administering sodium bicarbonate to alkalinize the urine
Which condition can sulfonamides provoke in patients with glucose-6-phosphate dehydrogenase deficiency?
Aplastic anemia
In which condition may sulfonamides cause hemolytic or aplastic anemia?
Hematopoietic disturbances
Which adverse effect of sulfonamides is treated by increasing urine flow?
Crystalluria
What is the agent of choice for moderately severe to severe pneumocystis pneumonia?
Intravenous Trimethoprim-Sulfamethoxazole
Which adverse effect is not associated with trimethoprim among the adverse effects of TMP-SMX?
Nausea and vomiting
What is the potential consequence of trimethoprim inhibiting creatinine secretion at the distal renal tubule?
Mild elevation of serum creatinine
Which condition may be effectively treated using oral pyrimethamine with a sulfonamide combination?
Toxoplasmosis
What are some untoward reactions associated with the combination of trimethoprim-sulfamethoxazole with sulfonamides?
Leukopenia and granulocytopenia
How does trimethoprim inhibit bacterial growth?
By inhibiting the conversion of dihydrofolic acid to tetrahydrofolic acid
What is a common mechanism of resistance to trimethoprim?
Reduced drug binding due to altered reductase
How is trimethoprim excreted from the body?
50-60% in urine
What impact does kidney disease have on trimethoprim dosage?
Dosage needs to be reduced
Which area of the body does trimethoprim show better antibacterial activity in due to its acidity?
Cerebrospinal fluid
When is oral trimethoprim commonly used alone?
In urinary tract infections
Which fluoroquinolone is considered the drug of choice in multi-drug resistant TB?
Levofloxacin
What causes emerging resistance to fluoroquinolones?
Point mutations in the target enzyme
What is a key feature of Levofloxacin that results in its high dose and short course administration?
Superior strength against gram-positive organisms
Which organisms are fluoroquinolones active against, besides gram-positive bacteria?
Atypical pneumonia agents and intracellular pathogens
What does resistance to one fluoroquinolone generally confer to other members of the class?
Cross-resistance
Why are Gatifloxacin, Gemifloxacin, and Moxifloxacin considered part of the latest group of fluoroquinolones?
Improved activity against gram-positive organisms
What is the mechanism of action of fluoroquinolones?
Inhibition of bacterial DNA synthesis
Which fluoroquinolone is known for its superior activity against gram-positive organisms?
Levofloxacin
What is the primary reason for using fluoroquinolones in combination with a second active agent when treating staphylococcal infections?
To prevent emergence of resistance while on therapy
Which fluoroquinolone is considered the least active against both gram-negative and gram-positive organisms?
Norfloxacin
Which group of fluoroquinolones possess excellent gram-negative activity and moderate to good activity against gram-positive bacteria?
Ciprofloxacin, Levofloxacin, Ofloxacin
What is the recommended timing for taking oral fluoroquinolones in relation to products containing divalent and trivalent cations?
2 hours before
Which fluoroquinolone does not require dosage adjustment for renal failure due to its metabolism in the liver?
Moxifloxacin
Which fluoroquinolone is considered effective in urinary tract infections caused by Pseudomonas aeruginosa?
Levofloxacin
For which type of infections are fluoroquinolones (except norfloxacin) commonly used?
Respiratory tract infections
Which fluoroquinolone is specifically mentioned as the drug of choice for prophylaxis and treatment of Anthrax?
Ciprofloxacin
In which condition are Levofloxacin and Ofloxacin recommended as alternative treatment options?
Chlamydial Urethritis
What is a common side effect associated with Fluoroquinolones?
Dizziness
Which factor is identified as a risk factor for tendinitis associated with Fluoroquinolones?
Renal insufficiency
What is a potential complication that can occur with Gatifloxacin, Levofloxacin, Gemifloxacin, and Moxifloxacin use?
QTC interval prolongation
When should Fluoroquinolones be avoided in relation to pregnancy?
In the absence of specific data
Which type of infection do Levofloxacin, Gemifloxacin, and Moxifloxacin effectively treat?
Lower respiratory tract infections
What is a condition in which Fluoroquinolones should be used with caution due to potential complications?
Uncorrected hypokalemia
Test your knowledge on oral and topical non-absorbable agents used in the treatment of various conditions. Topics covered include Sulfasalazine for gastrointestinal conditions and Sodium sulfacetamide, Mafenide acetate, and Silver for topical applications.
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