A nurse is administering desmopressin to a client who has diabetes insipidus. The nurse should monitor the client for which of the following adverse effects?

Atorvastatin is an HMG-CoA reductase inhibitorthat lowers cholesterol by blocking the rate-limiting step of hepatic cholesterol synthesis. Its primary therapeutic goal is the reduction of atherogenic lipoproteinsto prevent cardiovascular disease and stroke. Effective therapy is measured by a significant improvement in the lipid profile, specifically targeting the reduction of low-density lipoproteins(LDL).

Rationale:

A.Decreased HDL levels would indicate a worsening of the patient's cardiovascular risk profile rather than effective treatment. High-density lipoprotein (HDL) is considered "good" cholesterol because it helps remove other forms of cholesterol from the bloodstream. A successful response to statin therapy would involve maintaining or slightly increasing HDL levels to provide better cardioprotective benefits.

B.Increased serum transaminase levels are an adverse effect of atorvastatin indicating potential hepatotoxicity, not therapeutic effectiveness. Statins are metabolized by the liver and can occasionally cause inflammation or damage to hepatocytes. If these enzymes (AST and ALT) rise significantly, the nurse must report this finding as it may necessitate the discontinuation of the medication.

C.Decreased LDL levels are the hallmark indicator of effective atorvastatin therapy. Low-density lipoprotein is the primary target for statins because it contributes to plaque buildup in the arteries, leading to atherosclerosis. A significant reduction in LDL proves that the HMG-CoA reductase inhibitor is successfully lowering the production of harmful cholesterol and reducing overall cardiovascular risk.

D.Increased creatine kinase (CK) levels are a laboratory marker for muscle damage and a sign of a serious adverse effect called rhabdomyolysis. This condition involves the breakdown of skeletal muscle fibers, which can lead to acute renal failure. Elevated CK levels are a reason for concern and immediate clinical intervention, not a sign that the cholesterol-lowering treatment is working.

Spironolactoneis a potassium-sparing diuretic that functions as an aldosterone antagonistin the distal convoluted tubule and collecting duct. It promotes the excretion of sodium and water while retaining potassium, making it effective for hypertension but dangerous in the presence of renal insufficiency. Significant contraindications include pre-existing hyperkalemiaor concurrent use of other medications that inhibit the renin-angiotensin-aldosterone system, as these combinations exponentially increase the risk of lethal cardiac dysrhythmias.

Rationale:

A. The client is currently taking lisinopril, an ACE inhibitor, which also increases serum potassium by suppressing aldosterone secretion. Combining lisinopril with spironolactone creates a synergistic effect that leads to severe hyperkalemia. This drug-drug interaction is a major clinical concern because both agents reduce the kidneys' ability to excrete potassium. The nurse must report this concurrent therapy to prevent potential cardiac toxicityresulting from excessive potassium accumulation.

B. The client's potassium level of 5.6 mEq/L already indicates hyperkalemia, as it exceeds the normal physiological limit of 5.0 mEq/L. Administering spironolactone to a client with an already elevated potassium concentration is strictly contraindicated. Increasing the potassium burden through potassium-sparingeffects could lead to peaked T waves, conduction blocks, or asystole. This laboratory finding must be addressed and corrected before any further potassium-retaining medications are administered.

C. A BUN(blood urea nitrogen) of 30 mg/dL signifies impaired renal clearance and decreased glomerular filtration. Elevated nitrogenous waste products often indicate that the kidneys are unable to maintain proper electrolyte balance. Since spironolactone relies on renal excretion and affects renal tubular transport, its use in a client with azotemia is highly risky. This finding suggests the client is at an increased risk for metabolic imbalancesif the diuretic is initiated.

D. A creatininelevel of 2 mg/dL is double the upper limit of the normal range, indicating significant renal dysfunction. Spironolactone is generally contraindicated or requires extreme caution in patients with a creatinine clearance that is significantly reduced. Impaired renal function prevents the body from managing the potassium-sparing effects of the drug, leading to a rapid and dangerous rise in serum electrolytes. This objective marker of kidney failuremakes the new prescription inappropriate for the client's current clinical status.