A nurse is reviewing the medical history of a client who has a new diagnosis of diabetes mellitus and is asking about taking metformin.
Which of the following client conditions should the nurse identify as a contraindication for this medication?

Choice A rationale

Ocular erythema, or redness of the eye, is not a typical adverse effect associated with spironolactone. Spironolactone is a potassium-sparing diuretic that primarily acts on the renal tubules to inhibit aldosterone, affecting electrolyte balance and fluid excretion, not directly impacting ocular tissues or causing inflammatory responses in the eye.

Choice B rationale

Diarrhea is not a common or expected adverse effect of spironolactone. While gastrointestinal disturbances can occur with many medications, spironolactone is more commonly associated with effects related to its diuretic and anti-androgenic properties, such as electrolyte imbalances (hyperkalemia) or endocrine-related symptoms, rather than increased bowel motility.

Choice C rationale

Muscle weakness can occur as an adverse effect of spironolactone, particularly due to its potential to cause hyperkalemia. Spironolactone's mechanism of action involves conserving potassium, and elevated serum potassium levels (normal range 3.5-5.0 mEq/L) can impair the excitability of muscle cells, leading to symptoms like muscle weakness, fatigue, and in severe cases, cardiac dysrhythmias.

Choice D rationale

Depression is not a recognized or common adverse effect of spironolactone. Spironolactone's primary pharmacological actions are on the kidney and endocrine system, and it is not known to directly affect neurotransmitter systems in the brain in a way that would commonly induce depressive symptoms. Psychotropic effects are not typically associated with this medication.

Choice A rationale

Magnesium levels within the normal range (1.3 to 2.1 mEq/L) are important for overall electrolyte balance, but sodium polystyrene sulfonate specifically targets potassium. While hyperkalemia can sometimes be associated with other electrolyte imbalances, a normal magnesium level does not directly indicate a therapeutic response to sodium polystyrene sulfonate, as its primary action is not on magnesium.

Choice B rationale

Calcium levels within the normal range (9 to 10.5 mg/dL) are essential for various physiological functions. Sodium polystyrene sulfonate primarily exchanges sodium ions for potassium ions, not calcium. Therefore, a normal calcium level does not reflect a therapeutic response to the medication, which is specifically aimed at reducing elevated potassium levels.

Choice C rationale

Sodium levels within the normal range (136 to 145 mEq/L) are crucial for fluid balance and neurological function. Sodium polystyrene sulfonate exchanges sodium for potassium, meaning it increases the body's sodium load. While a normal sodium level is desirable, it does not directly indicate the therapeutic efficacy of the medication in reducing potassium.

Choice D rationale

Potassium 4.8 mEq/L (3.5 to 5 mEq/L) indicates a therapeutic response. Sodium polystyrene sulfonate is an ion-exchange resin used to treat hyperkalemia by exchanging potassium ions for sodium ions in the gastrointestinal tract. A potassium level returning to within the normal range, from a previously elevated state, signifies that the medication has effectively lowered the excess potassium.