Which drug is commonly administered for prophylaxis against Streptococcus and Staphylococcus infections before surgery?

Cefazolin is commonly administered for prophylaxis against Streptococcus and Staphylococcus infections before surgery because it has a strong efficacy profile against these bacteria. This first-generation cephalosporin is particularly useful in surgical settings due to its effectiveness against skin flora, which includes Staphylococcus species, and its ability to prevent post-operative infections.

The choice of Cefazolin for surgical prophylaxis is also supported by its pharmacokinetic properties, which allow for adequate tissue penetration and coverage during the critical time of surgery. Its relatively low toxicity and broad spectrum of activity against common pathogens make it a preferred option in various surgical procedures, particularly orthopedic, cardiac, and some gastrointestinal surgeries.

This contrasts with the other drugs listed, which have different indications and are not typically used as first-line agents for surgical prophylaxis against these specific pathogens. For example, Cefotetan is more commonly used for anaerobic coverage, Cefuroxime might be chosen for certain infections but not specifically for surgical prophylaxis against skin flora, and Ceftriaxone, while effective for a broader range of bacteria, is not usually chosen for surgical prophylaxis due to its longer half-life and different pharmacokinetics.