Which of the following is the goal of monitoring peak and trough levels during antibacterial therapy?

A. Decision to administer either a bactericidal or bacteriostatic drug:

Culture and sensitivity tests provide information about the susceptibility of the microorganism to specific antimicrobial agents. Based on this information, healthcare providers can choose between bactericidal (agents that kill bacteria) or bacteriostatic (agents that inhibit bacterial growth) drugs. For example, if the culture indicates that the microorganism is susceptible to a bactericidal drug, such as penicillin, the healthcare provider may choose to administer that type of drug.

B. Microbial susceptibility to an anti-infective:

This option accurately describes one of the primary purposes of culture and sensitivity tests. These tests determine whether the microorganism causing the infection is susceptible or resistant to specific antimicrobial agents. This information guides the selection of the most appropriate anti-infective therapy to effectively treat the infection.

C. Duration of the antibacterial drug therapy:

While culture and sensitivity tests provide valuable information about microbial susceptibility to antimicrobial agents, they do not specifically determine the duration of antibacterial drug therapy. The duration of therapy is often determined based on factors such as the type and severity of the infection, the patient's response to treatment, and clinical guidelines, rather than solely on the results of culture and sensitivity tests.

D. Decision to administer empiric therapy:

Empiric therapy involves the initiation of antimicrobial treatment based on clinical judgment and knowledge of likely pathogens before culture and sensitivity results are available. Culture and sensitivity tests help confirm the causative microorganism and guide subsequent treatment decisions, including adjustments to therapy based on the results. Therefore, while culture and sensitivity tests inform decisions regarding antimicrobial therapy, they do not directly determine whether empiric therapy should be initiated.

A. Kanamycin (Kantrex):

Kanamycin is an aminoglycoside antibiotic, but it is not commonly used as a first-line treatment for MRSA infections. Aminoglycosides are not typically preferred for treating MRSA because they are not as effective against these resistant bacteria compared to other agents like vancomycin.

B. Vancomycin:

Vancomycin is a glycopeptide antibiotic and is considered the drug of choice for the treatment of MRSA infections, including serious bloodstream infections, pneumonia, and skin and soft tissue infections. It works by inhibiting cell wall synthesis in bacteria, including MRSA.

C. Streptomycin:

Streptomycin is another aminoglycoside antibiotic, similar to kanamycin. Like kanamycin, streptomycin is not typically used as a first-line treatment for MRSA infections because it is less effective against resistant strains compared to other agents like vancomycin.

D. Penicillin:

Penicillin and other beta-lactam antibiotics are ineffective against MRSA because MRSA is resistant to these antibiotics, including methicillin. Therefore, penicillin would not be an appropriate choice for treating MRSA infections.