Does Spironolactone (a potassium-sparing diuretic) cause thrombocytopenia and metabolic acidosis?

From the Guidelines

Spironolactone does not typically cause thrombocytopenia or metabolic acidosis. Spironolactone is a potassium-sparing diuretic that works by blocking aldosterone receptors, primarily used to treat conditions like heart failure, hypertension, edema, and hyperaldosteronism. While spironolactone has several known side effects, including hyperkalemia, gynecomastia, menstrual irregularities, and occasional skin reactions, thrombocytopenia (low platelet count) is not a commonly reported adverse effect, as seen in the 2022 AHA/ACC/HFSA guideline for the management of heart failure 1. Similarly, spironolactone does not cause metabolic acidosis; in fact, it may occasionally lead to metabolic alkalosis due to its effects on electrolyte balance. If a patient on spironolactone develops thrombocytopenia or metabolic acidosis, clinicians should investigate other potential causes rather than attributing these conditions to spironolactone therapy. The medication's primary metabolic concern is hyperkalemia (elevated potassium levels), which requires monitoring, especially in patients with renal impairment or those taking other potassium-retaining medications, as highlighted in the expert consensus document on the management of hyperkalaemia in patients with cardiovascular disease treated with renin angiotensin aldosterone system inhibitors 1. Key considerations for spironolactone use include careful monitoring of potassium, renal function, and diuretic dosing at initiation and follow-up, as recommended in the 2013 ACCF/AHA guideline for the management of heart failure 1 and the 2017 ACC/AHA/HFSA focused update of the 2013 ACCF/AHA guideline for the management of heart failure 1.

Some key points to consider when using spironolactone include:

• Monitoring potassium levels and renal function regularly
• Avoiding potassium-rich foods and NSAIDs
• Discontinuing potassium supplementation
• Careful dosing and monitoring in patients with renal impairment
• Being aware of the potential for hyperkalemia and worsening renal function, as discussed in the provided evidence 1.

Overall, spironolactone is a valuable medication for treating certain conditions, but its use requires careful consideration and monitoring to minimize the risk of adverse effects, particularly hyperkalemia, as emphasized in the most recent guideline evidence 1.

From the FDA Drug Label

1. 5 Cholestyramine Hyperkalemic metabolic acidosis has been reported in patients given spironolactone concurrently with cholestyramine. There is no direct information in the label about spironolactone causing thrombocytopenia. However, the label does mention that metabolic acidosis can occur when spironolactone is given concurrently with cholestyramine, specifically hyperkalemic metabolic acidosis 2.

From the Research

Spironolactone Side Effects

• Spironolactone can cause hyperkalemia, as evidenced by a significant increment in serum potassium levels in patients treated with the drug 3, 4.
• Metabolic acidosis is also a potential side effect of spironolactone, particularly in patients with renal dysfunction or those taking other medications that affect kidney function 5, 6.
• The risk of hyperkalemia and metabolic acidosis may be increased in patients with chronic kidney disease (CKD), especially those with more severe renal impairment 4, 7.
• However, some studies suggest that spironolactone can be safely used in patients with mild to moderate CKD, with careful monitoring of potassium levels and renal function 7.

Hematologic Effects

• There is no direct evidence in the provided studies to suggest that spironolactone causes thrombocytopenia.
• The studies primarily focus on the effects of spironolactone on serum electrolytes, renal function, and acid-base metabolism, with no mention of hematologic effects such as thrombocytopenia.

Renal Function

• Spironolactone can affect renal function, particularly in patients with pre-existing kidney disease, and may cause a decrease in eGFR 4, 7.
• However, the drug can also have beneficial effects on survival in patients with heart failure and reduced renal function, despite the potential risks of hyperkalemia and worsened renal function 4.