Question

Which of the following is not an antibiotic?
A. Chloramphenicol
B. Ofloxacin
C. Penicillin
D. Prontosil

Answer 1

In order to answer this question, we should know whether which option is not an antibiotic, we should go through each of the options separately, we will discuss their composition and why they are usually used.

Complete step-by-step answer:
An antibiotic is a substance that is capable of destroying or weakening certain microorganisms, especially bacteria or fungi, those cause infections or infectious diseases. Antibiotics are usually produced by or synthesized from other microorganisms, such as moulds.
In option (A), Chloramphenicol is antibiotic or antagonistic with most cephalosporins and using both together should be avoided in the treatment of infections. Chloramphenicol is bacteriostatic by inhibiting protein synthesis. It prevents protein chain elongation by inhibiting the peptidyl transferase activity of the bacterial ribosome.
In option (B), Ofloxacin is a fluoroquinolone antibiotic that fights bacteria in the body. Ofloxacin is used to treat bacterial infections of the skin, lungs, prostate, or urinary tract (bladder and kidneys). Ofloxacin is also used to treat pelvic inflammatory disease and Chlamydia and/or gonorrhoea.
In option (C), Penicillin is an antibiotic used to treat certain types of bacterial infections. Common side effects include diarrhoea and stomach upset, and some people may have an allergic reaction to penicillin—the effects can range from mild to severe.
In option (D), Prontosil is an antibacterial agent containing sulphur. It has a relatively broad effect against gram-positive cocci but not against enterobacteria. Therefore, Prontosil is not an antibiotic.

Hence, the correct answer is option (D).

Note: Antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity.