A nurse is caring for a client who is receiving vancomycin for a severe infection caused by methicillin-resistant Staphylococcus aureus (MRSA). The client also takes furosemide for heart failure.
Which of the following adverse effects should the nurse monitor for in this client? (Select all that apply.).

The combination of trimethoprim and sulfamethoxazole has a synergistic effect that inhibits bacterial growth more effectively than either drug alone. This means that the two drugs work together to produce a greater effect than the sum of their individual effects.

Choice B is wrong because the combination of trimethoprim and sulfamethoxazole does not have an additive effect that reduces the dosage and frequency of administration of each drug.

The dosage and frequency of administration are determined by the severity of the infection, the renal function of the client, and the susceptibility of the bacteria.

Choice C is wrong because the combination of trimethoprim and sulfamethoxazole does not have an antagonistic effect that prevents the development of resistance to either drug.

Antagonistic effect means that one drug reduces or cancels out the effect of another drug.

The combination of trimethoprim and sulfamethoxazole may still cause resistance in some bacteria.

Choice D is wrong because the combination of trimethoprim and sulfamethoxazole does not have a selective effect that targets only the bacteria causing the UTI and spares the normal flora.

Selective effect means that a drug affects only certain types of cells or organisms.

The combination of trimethoprim and sulfamethoxazole is a broad-spectrum antibiotic that can affect both gram-positive and gram-negative bacteria, including some normal flora.

Hearing loss and nephrotoxicity are possible adverse effects of vancomycin, especially when used with other drugs that can affect the kidneys or ears, such as furosemide. The nurse should monitor the client’s renal function tests, serum vancomycin levels, and hearing acuity while receiving this combination of drugs.

Choice C, red man syndrome, is a hypersensitivity reaction to vancomycin that causes flushing, itching, and rash on the face, neck, and upper body.It is not related to furosemide use and can be prevented by slowing the infusion rate of vancomycin.

Choice D, hypokalemia, is a low level of potassium in the blood that can be caused by furosemide, a loop diuretic that increases the excretion of potassium.However, vancomycin does not affect potassium levels and does not increase the risk of hypokalemia.

Choice E, thrombocytopenia, is a low level of platelets in the blood that can cause bleeding problems.

It is a rare side effect of vancomycin that occurs in less than 1% of patients.It is not related to furosemide use and does not occur more frequently with this combination of drugs.