A drug that is a fifth-generation cephalosporin which is the first in its class effective against MRSA is:

Allergic reaction: An allergic reaction can manifest in various ways, including rash, itching, and difficulty breathing. However, the specific symptoms described, along with the context of vancomycin administration, point to red man syndrome in this case.

Rhabdomyolysis: Rhabdomyolysis is a condition where damaged muscle tissue breaks down and releases a protein called myoglobin into the bloodstream. This can cause kidney damage, but the symptoms described do not align with rhabdomyolysis.

Stevens-Johnson syndrome: Stevens-Johnson syndrome is a severe skin reaction that can cause skin and mucous membranes to blister, peel, and can be life-threatening. While it can present with rash and other skin symptoms, the symptoms mentioned in the scenario are more characteristic of red man syndrome.

Red man syndrome: As mentioned earlier, red man syndrome is an allergic reaction to vancomycin characterized by flushing, rash, pruritus, and urticaria (hives), along with rapid heart rate and low blood pressure. It is specific to vancomycin and can be prevented or minimized by slowing down the infusion rate and administering antihistamines.

A. "Cephalosporins are assigned to generations based on their relative costs to administer."
This statement is incorrect. The classification of cephalosporins into generations is based on their antimicrobial spectrum and activity against specific bacteria, not their cost.

B. "Later generations of cephalosporins have lower resistance to destruction by beta-lactamases."
This statement is not accurate. In fact, later generations of cephalosporins have increased resistance to destruction by beta-lactamases, which are enzymes produced by bacteria that can break down certain antibiotics.

C. "Cephalosporins have increased activity against gram-negative bacteria with each new generation."
This statement is correct. Cephalosporins are grouped into generations (first to fifth) based on their antibacterial spectrum. As the generations progress, there is an increase in activity against gram-negative bacteria, among other improvements in their spectrum.

D. "First-generation cephalosporins have better penetration of the cerebrospinal fluid."
This statement is generally true. First-generation cephalosporins have better penetration into the cerebrospinal fluid, making them useful for treating certain central nervous system infections.