Correct Answer: C

Rationale: When prednisone is prescribed for a client with diabetes mellitus who is taking Humulin NPH insulin daily, the nurse should anticipate an increased amount of daily Humulin NPH insulin. Prednisone, a glucocorticoid, can elevate blood glucose levels, requiring an increase in insulin dosage to maintain optimal blood sugar control.

Correct Answer: A

Rationale: The correct answer is to check the potassium level before administering furosemide (Lasix) to a client with heart failure. Furosemide is a loop diuretic that can cause hypokalemia, so it is crucial to assess the potassium level to prevent complications like cardiac arrhythmias associated with low potassium levels.

Correct Answer: B

Rationale: Guaifenesin is an expectorant used to help loosen mucus and make coughs more productive. Taking it with a full glass of water helps decrease the viscosity of secretions, making it easier to expel mucus from the respiratory tract. It is important not to crush sustained-release tablets, as this can alter the intended release of the medication and lead to potential adverse effects.

Correct Answer: D

Rationale: The primary action of tamoxifen, an antineoplastic medication used in metastatic breast carcinoma, is to compete with estradiol for binding to estrogen receptors in tissues with high receptor concentrations. By doing so, tamoxifen reduces DNA synthesis and estrogen response, leading to its therapeutic effect in inhibiting the growth of estrogen-sensitive breast cancer cells.

Correct Answer: C

Rationale: The correct answer is C. Silver sulfadiazine is an antibacterial used to treat burns, helping in the healing process. It does not permanently stain the skin. Therefore, the statement indicating a lack of understanding is that the medication will permanently stain the skin.