Wk 7. Antibiotics part 2 Flashcards Preview

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Flashcards in Wk 7. Antibiotics part 2 Deck (28)
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1. How to tetracyclines inhibit the replication of bacteria?

Inhibits protein synthesis at ribosomes


2. How long should a patient wait after taking tetracycline before he has a glass of milk?

2 hours


3. Why are tetracyclines avoided in children younger than 8 years of age?

Discoloration and hypoplasia of teeth


4. What precautions should patients take with tetracycline?

Sun protection for photosensitivity. Take with a full glass of water to prevent esophageal ulcerations.


5. How does erythromycin increase the chance of drug interactions?

Inhibits hepatic drug metabolism by P450 system.


6. What is the major risk of drug interactions with erythromycin?

QT prolongation, which places person at risk for Torsades de Pointes,


7. How does erythromycin inhibit the replication of bacteria?

Inhibits protein synthesis at ribosomes


8. 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.


9. How does clarithromycin (Biaxin) inhibit the replication of bacteria?

Inhibits protein synthesis at ribosomes


10. Which macrolide does not inhibit hepatic enzymes? What drug interaction is still significant with this drug?

Azithromycin (Zithromax). Raises warfarin (Coumadin) levels.


11. Why is telethromycin (Ketek) only used for multidrug-resistant Streptococcus pneumonia?



12. How do sulfonamides inhibit replication of bacteria?

Competes with PABA in synthesizing folic acid and inhibits enzyme (dihydrofolate reductase) used to synthesize folic acid


13. Why are sulfonamides contraindicated for infants less than 2 months old?



14. Which antibiotic drug class is avoided in patients with G6PD deficiency? Why?

Sulfonamides may cause hemolytic anemia.


15. 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.


16. 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.


17. How do fluoroquinolones kill bacteria?

Inhibit synthesis of nucleic acids


18. Why should fluoroquinolones not be used in patients under the age of 18?

Tendon injury


19. For what type of bacteria are aminoglycosides given?

Aerobic gram negative bacilli


20. 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.


21. Ciprofloxacin (Cipro) is given for what common disease processes?

UTIs, enteric organisms.


22. What are the two mechanisms of action for aminoglycosides?

Inhibit protein synthesis at ribosomes and insert abnormal proteins into the cell wall.


23. 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.


24. Discuss the distribution of aminoglycosides.

Unable to cross cell membranes. Not absorbed orally and does not cross blood-brain barrier.


25. What two organs can be damaged by aminoglycosides?

Ears, kidneys


26. When are gentamicin peak and trough levels drawn?

Multiple doses: Peak level 30 min after IM or after 30-min IV infusion. Trough level immediately before next dose.
Daily dose: Trough level 1 hr before next dose. No need for peak level.


27. What two antibiotics are reserved mainly for anaerobic bacteria?

Clindamycin (Cleocin) and metronizadole (Flagyl).


28. What viruses does acyclovir (Zorivax) treat? Does it cure the disease?

Herpes simplex viruses (HSVs) – cold sores and genital infections, varicella-zoster virus (VZV) – chickenpox and shingles. The drug manages the symptoms, but does not cure or prevent transmission.