Can any of these medications cause hyponatremia?

Medications That Can Cause Hyponatremia in Your Regimen

Indapamide is the medication most likely to cause hyponatremia in your current regimen. This thiazide-like diuretic is well-documented to cause low sodium levels, particularly in older adults.

Analysis of Your Medications

High Risk for Hyponatremia:

• Indapamide 1.25mg OD:
  • Specifically mentioned in guidelines as causing hyponatremia 1
  • FDA labeling explicitly warns about severe hyponatremia, particularly in elderly females 2
  • Even at the lower 1.25mg dose you're taking, hyponatremia is a recognized risk
  • Can cause hyponatremia within 2-6 weeks of starting therapy 3, 4

Moderate Risk for Hyponatremia:

• Perindopril 8mg OD:
  • ACE inhibitors like perindopril can occasionally contribute to hyponatremia, especially when combined with diuretics
  • The combination of indapamide and perindopril increases the risk of hyponatremia through complementary mechanisms

Low/No Risk for Hyponatremia:

• Salofalk 1000mg BID (mesalamine): Not typically associated with hyponatremia
• Tylenol Arthritis TID (acetaminophen): Not known to cause hyponatremia
• Rosuvastatin 5mg: Not associated with hyponatremia
• ASA 81mg OD (aspirin): Not typically associated with hyponatremia

Mechanism of Indapamide-Induced Hyponatremia

Indapamide causes hyponatremia through:

1. Inhibition of sodium reabsorption in the distal tubule
2. Increased water retention due to stimulation of antidiuretic hormone (ADH)
3. Impaired urinary dilution capacity

Risk Factors for Hyponatremia with Indapamide

• Age (especially >60 years)
• Female gender
• Low body weight
• Reduced kidney function
• Excessive fluid intake
• Low salt diet
• Concomitant use of other medications affecting sodium balance (like your perindopril)

Monitoring and Management

If hyponatremia is suspected:

1. Check serum sodium levels
2. If sodium is <130 mmol/L, consider:
   • Reducing indapamide dose or discontinuing it
   • Switching to a different antihypertensive with lower risk of hyponatremia
   • Salt supplementation if appropriate
   • Fluid restriction if euvolemic or hypervolemic hyponatremia is present

Warning Signs of Hyponatremia

Watch for:

• Headache, confusion, or altered mental status
• Nausea and vomiting
• Muscle cramps or weakness
• Fatigue or lethargy
• Seizures (in severe cases)

Important Considerations

• Hyponatremia from indapamide can develop rapidly (within 2 weeks) or gradually over months 3, 4
• Severe cases with sodium levels <125 mmol/L may require hospitalization and careful correction 5, 6
• Hypokalemia often accompanies indapamide-induced hyponatremia, so potassium levels should also be monitored 2, 3
• The risk of hyponatremia is dose-dependent, but can occur even at the lower 1.25mg dose you're taking 2

If you're experiencing symptoms of low sodium, contact your healthcare provider promptly for evaluation and potential medication adjustment.