Question

Why is it preferable, if possible, to take a narrow spectrum antibiotic over a broad spectrum antibiotic?

Group of answer choices

narrow spectrum antibiotics have a limited range of effectiveness among different bacterial species but they each have several modes of action which make them more effective than broad spectrum antibiotics

narrow spectrum antibiotics are less likely to be overcome by antimicrobial resistance mechanisms compared to broad spectrum antibiotics

narrow spectrum antibiotics always have a high theraputic index compared to broad spectrum antibiotics

narrow spectrum antibiotics are less likely to destroy the normal gut microflora which can lead to development of super-infections after treatment

narrow spectrum antibiotics attack many more species of bacteria compared to broad spectrum antibiotics

Answer 1

Antibiotics are drugs used to cure infections because of low toxicity for humans and animals. They are substances produced wholy or partly by chemical synthesis, which in low concentrations inhibits the growth or destroys microorganisms by intervening in their metabolic process. Based upon the range of microorganisms or bacteria affected by antibiotic expressed as its spectrum of action, antibiotic are primarily of two types: broad spectrum antibiotics and narrow spectrum antibiotics. The former kill or inhibit wide range of Gram-positive and Gram-negative bacteria while the latter are effective mainly against limited species of bacteria. Examples of broad spectrum antibiotics include ampicillin, chloramphenicol, etc whereas that of narrow spectrum include Penicillin G.

Narrow-spectrum antibiotic are active against a selected group of bacterial species. These are used for the specific infection when the causative organism is known and allow to kill only those bacteria species that are unwanted (i.e causing disease). These are less likely to destroy the normal gut microflora and will not kill as many of the normal microorganisms in the body as the broad spectrum antibiotics. So the narrow-spectrum antibiotic has less ability to cause superinfection. These cause less resistance of the bacteria, since it will deal with only specific bacteria. Another factor regarding the preference of narrow spectrum antibiotic over broad spectrum antibiotic is the low tendency of narrow spectrum antibiotic for bacterial resistance development.