Wk 7. Antibiotics part 2 Flashcards
(28 cards)
- How to tetracyclines inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
- How long should a patient wait after taking tetracycline before he has a glass of milk?
2 hours
- Why are tetracyclines avoided in children younger than 8 years of age?
Discoloration and hypoplasia of teeth
- What precautions should patients take with tetracycline?
Sun protection for photosensitivity. Take with a full glass of water to prevent esophageal ulcerations.
- How does erythromycin increase the chance of drug interactions?
Inhibits hepatic drug metabolism by P450 system.
- What is the major risk of drug interactions with erythromycin?
QT prolongation, which places person at risk for Torsades de Pointes,
- How does erythromycin inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
- What are common adverse effects of erythromycin? How can this be mitigated?
Nausea, vomiting, diarrhea, epigastric pain. Give ethylsuccinate or enteric-coated tablets with food.
- How does clarithromycin (Biaxin) inhibit the replication of bacteria?
Inhibits protein synthesis at ribosomes
- Which macrolide does not inhibit hepatic enzymes? What drug interaction is still significant with this drug?
Azithromycin (Zithromax). Raises warfarin (Coumadin) levels.
- Why is telethromycin (Ketek) only used for multidrug-resistant Streptococcus pneumonia?
Hepatoxicity.
- How do sulfonamides inhibit replication of bacteria?
Competes with PABA in synthesizing folic acid and inhibits enzyme (dihydrofolate reductase) used to synthesize folic acid
- Why are sulfonamides contraindicated for infants less than 2 months old?
Kernicterus
- Which antibiotic drug class is avoided in patients with G6PD deficiency? Why?
Sulfonamides may cause hemolytic anemia.
- What drugs should be used with caution if the person in allergic to sulfonamides? Should a person with anaphylaxis try these drugs?
Sulfonylureas (oral antidiabetic drugs), loop diuretics, thiazide diuretics, and Celebrex (COX-2 inhibitor). Absolutely not due to a higher risk of hypersensitivity.
- Why should a patient stop using a sulfonamide with a blistering, sunburn-like rash? What other skin reaction may occur
Risk for Stevens-Johnson Syndrome. Photosensitivity.
- How do fluoroquinolones kill bacteria?
Inhibit synthesis of nucleic acids
- Why should fluoroquinolones not be used in patients under the age of 18?
Tendon injury
- For what type of bacteria are aminoglycosides given?
Aerobic gram negative bacilli
- Fluoroquinolones are ordered to be given in the morning with a multivitamin with minerals. Why is this contraindicated?
Calcium, aluminum, magnesium, iron, zinc may combine with the fluoroquinolone and prevent its absorption. Give fluoroquinolones on an empty stomach.
- Ciprofloxacin (Cipro) is given for what common disease processes?
UTIs, enteric organisms.
- What are the two mechanisms of action for aminoglycosides?
Inhibit protein synthesis at ribosomes and insert abnormal proteins into the cell wall.
- Instead of keeping the serum drug levels above the MIC (minimum inhibitory concentration), how do aminoglycosides kill bacteria?
Concentration-dependent kill with post-antibiotic effect.
- Discuss the distribution of aminoglycosides.
Unable to cross cell membranes. Not absorbed orally and does not cross blood-brain barrier.
