30 Questions
What is the term for the maximum drug concentration during repeated dosing cycles?
Peak
Which sulfa antibiotic is classified as an oral absorbable drug?
Sulfadoxine
What adverse reaction can occur with the use of sulfamethoxazole and trimethoprim?
Photosensitivity
Which bacterial species is NOT covered by sulfamethoxazole and trimethoprim?
Pseudomonas aeruginosa
What is the mechanism of action of trimethoprim?
Inhibition of folic acid synthesis
Which Sulfa antibiotic is a topical agent?
Sulfasalazine
Which adverse drug reaction can be avoided by proper dosage adjustments?
Kernicterus
What is the spectrum of activity of sulfamethoxazole and trimethoprim?
Wide range of both Gram-positive and Gram-negative coverage
What severe skin reaction can occur due to sulfa antibiotics?
Steven-Johnson Syndrome
Which bacterium does sulfamethoxazole and trimethoprim NOT cover?
Pseudomonas aeruginosa
What is the mechanism of action of Linezolid (Zyvox®)?
Disrupts bacterial translation process
Which clinical condition is NOT an indication for Vancomycin?
Anaerobic infections
What is the target trough level of Vancomycin for UTI and skin/soft tissue infections?
10-15 mcg/mL
What is the major adverse effect associated with Daptomycin (Cubicin®) therapy?
Optic neuropathy
Which of the following statements regarding UTI evaluation is correct?
Acute mental status change is a key symptom of UTI
What is the primary metabolic pathway for Linezolid (Zyvox®)?
Oxidation
Which organism is Linezolid (Zyvox®) bacteriostatic against?
Enterococci
In which condition is Daptomycin (Cubicin®) spectrum of activity limited to only Gram-positive organisms?
Pneumonia
Which of the following is NOT a risk factor for hemolytic anemia in neonates?
Ciprofloxacin therapy
Which condition does NOT warrant the use of IV antibiotics initially according to the text?
Pneumonia
Which bacterial species is NOT mentioned in the text as covered by the antibiotics discussed?
Streptococcus pneumoniae
Which antibiotic mentioned is preferred for its activity against multidrug-resistant Gram-negative organisms?
Plazomicin
What is NOT an adverse effect associated with the use of Mafenide cream or solution?
Metabolic alkalosis
Which antibiotic mentioned in the text has the unique property of inhibiting carbonic anhydrase?
Sulfamylon
What type of infections is Silver Sulfadiazine 1% Cream commonly used for?
Burn wound infections
Which of the mentioned antibiotics is NOT part of the glycopeptide antibiotics class?
Gentamicin
What distinguishes the pharmacokinetics of aminoglycosides in patients with cystic fibrosis compared to the general population?
They have altered PK parameters and don't follow population-based principles
What is a common clinical indication for the use of glycopeptide antibiotics like Vancomycin?
Neonatal meningitis
Which of the following bacteria is notably NOT covered by the antibiotics discussed?
Pseudomonas aeruginosa
What special property defines the dosing regimen of aminoglycosides to optimize their action?
Once-daily large dose is superior to multiple small doses
Study Notes
Pharmacokinetics Principles
- Peak: maximum drug concentration during repeated dosing cycles
- Trough: minimum drug concentration during repeated dosing cycles
- Steady state: rate of drug elimination = rate of administration, usually after 4-5 half-lives
Sulfonamides
- Classification: oral absorbable (sulfisoxazole, sulfamethoxazole, sulfadoxine), oral non-absorbable (sulfasalazine), topical agents (sulfacetamide, mafenide, silver sulfadalazine)
- Mechanism of Action: bacteriostatic inhibitors of folic acid synthesis
- Combined with Trimethoprim: bactericidal, prevents formation of active form of folic acid
- Adverse Effects: hypersensitivity reactions, Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis, exfoliative dermatitis, photosensitivity, nausea, vomiting, diarrhea, hepatotoxicity, bone marrow suppression
Sulfamethoxazole (SMZ) & Trimethoprim (TMP)
- Brand name: Bactrim
- IV solution: SMZ 80mg-TMP 16mg/mL
- DS tablet: SMZ 800mg-TMP 160mg
- SS tablet: SMZ 400mg-TMP 80mg
- Bioavailability: 70-90%, hepatically metabolized, renally eliminated
- Spectrum of activity: wide range of both Gram + and Gram - coverage, except Pseudomonas aeruginosa, Bacteroides fragilis, and Enterococci
- Indications: Nocardia sp., Stenotrophomonas maltophilia, MRSA, UTI, bacteremia, osteomyelitis, pneumonia, CNS infections, endocarditis, skin/soft tissue infections
- Adverse Effects: infusion reaction, ototoxicity, nephrotoxicity, acute tubular necrosis
Linezolid (Zyvox)
- Mechanism of Action: binds to bacterial 50S subunit of ribosomal RNA, prevents formation of functional 70S initial complex, disrupts bacterial translation process
- Bacteriostatic against Enterococci, bactericidal against Streptococci
- Spectrum of activity: covers Gram + organisms only, MRSA, VRE, Streptococcus sp., Staphylococcus sp.
- Clinical Uses: skin/soft tissue infections, pneumonia, bacteremia, intra-abdominal infections, endocarditis, CNS infections
- Adverse Effects: myelosuppression, optic and peripheral neuropathy, interactions with serotonergic medications
Daptomycin (Cubicin)
- Mechanism of Action: binds to components of cell membrane, causes rapid depolarization, inhibits intracellular synthesis of DNA, RNA, and protein
- Bactericidal, concentration-dependent
- Spectrum of activity: covers Gram + organisms only, MRSA, VRE, Streptococcus sp., Staphylococcus sp.
- Clinical Uses: skin/soft tissue infections, bacteremia, intra-abdominal infections, endocarditis
- Adverse Effects: risk of hemolytic anemia in G6PD deficiency, nausea, peripheral neuropathy, pulmonary fibrosis, liver injury, DRESS
Aminoglycosides
- Mechanism of Action: bind to 30S subunit, interfere with protein synthesis, block formation of initiation complex, misreading of mRNA
- Bactericidal, concentration-dependent killing, prolonged postantibiotic effect
- Clinical Indications: UTI, pyelonephritis, double coverage for Pseudomonas in septic shock, synergy for Gram + endocarditis, type III open fracture infection prophylaxis, cystic fibrosis
- Adverse Effects: nephrotoxicity, ototoxicity, contraindicated in patients with myasthenia gravis
Test your knowledge on pharmacokinetics principles including peak, trough, and steady state, along with understanding the uses, mechanism of action, and potential side effects of sulfa antibiotics. This quiz covers different classifications of sulfonamides such as oral absorbable drugs like Sulfisoxazole and Sulfamethoxazole, oral non-absorbable drug like Sulfasalazine, and topical agents like Sulfacetamide.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
