Ch 84: Drugs That Weaken the Bacterial Cell Wall I: Penicillins

Question 1

Despite the fact that penicillin is active against most gram-positive bacteria (except penicillinase-producing staphylococci), gram-negative cocci, anaerobic bacteria, and spirochetes, penicillin is still considered a…

Answer 1

…narrow-spectrum agent.

p. 1018

Question 2

Which species and associated diseases is Penicillin G effective against?

Answer 2

Pneumonia and meningitis caused by Streptococcus pneumoniae (pneumococcus)
Pharyngitis caused by Streptococcus pyogenes
Infectious endocarditis caused by Streptococcus viridans

Gas gangrene caused by Clostridium perfringens
Tetanus caused by Clostridium tetani
Anthrax caused by Bacillus anthracis

Meningitis caused by N. meningitidis (meningococcus)
Gonorrhea (used only for those strains of N. gonorrhoeae which are non-penicillinase-producing)
Syphilis caused by the spirochete Treponema pallidum

(p. 1019)

Question 3

Is oral administration of penicillin preferred?

Answer 3

No, this route is obsolete.

p. 1019

Question 4

All 4 salt forms of penicillin may be administered…

Answer 4

…IM.

p. 1019

Question 5

Procaine and benzathine salt form of penicillin should never be administered….

Answer 5

…IV.

p. 1019

Question 6

Penicillin metabolism occurs by…

Answer 6

…the kidneys.
Active tubular secretion (90%), glomerular filtration (10%).

(p. 1019)

Question 7

Penicillins are the most common cause of…

Answer 7

…drug allergy.

p. 1020

Question 8

What percent of patients allergic to penicillins also show cross-sensitivity to cephalosporins?

Answer 8

1%

p. 1020

Question 9

Redness, itching, and pain following an IM injection of penicillin indicates…

Answer 9

…an allergic reaction.

p. 1020

Question 10

Penicillin G, in large IV doses, can cause…

Answer 10

…hyperkalemia and associated cardiac dysrhythmias.

p. 1020

Question 11

What are the most common side effects of ampicillin?

Answer 11

Rash and diarrhea

p. 1022

Question 12

High concentrations of penicillins can inactivate what other type of antimicrobial?

Answer 12

Aminoglycosides

p. 1023