A nurse is administering a daily dose of vancomycin at 10:00 AM. At which time should the nurse obtain the patient's blood sample to determine the trough level?

A. Gentamicin: Gentamicin is an aminoglycoside antibiotic effective against many bacteria, but it's not the first choice for MRSA. Vancomycin or other alternatives are preferred due to the rising resistance of MRSA to gentamicin.

B. Nafcillin: Nafcillin is a penicillin antibiotic, often used for penicillin-sensitive staphylococcal infections. However, it is not effective against MRSA, which is resistant to many penicillin-based antibiotics.

C. Vancomycin: Vancomycin is a glycopeptide antibiotic used to treat a variety of bacterial infections, including MRSA. It works by inhibiting cell wall synthesis in bacteria, making it effective against Gram-positive bacteria that have developed resistance to other antibiotics like methicillin (which MRSA has).

D. Penicillin: Penicillin is a group of antibiotics that includes drugs like amoxicillin and ampicillin. MRSA is resistant to penicillin-based antibiotics, so they are not effective against MRSA infections.

A. Dermatitis and headaches: Prednisone use can sometimes cause skin issues, but dermatitis is not a common side effect. Headaches can also occur, but they are not specific to long-term prednisone therapy.

B. Heart failure and headaches: Prednisone does not directly cause heart failure. Headaches can occur but are not specific indicators of prednisone side effects.

C. Hyperglycemia and osteoporosis: Prednisone can lead to elevated blood glucose levels (hyperglycemia) and increased bone loss (osteoporosis) when used long-term. Regular monitoring is essential to manage these potential side effects.

D. Weight loss and hypoglycemia: Prednisone can cause weight gain rather than weight loss. Hypoglycemia (low blood sugar) is not a common side effect of prednisone; it typically causes hyperglycemia (high blood sugar) instead.