Interactions between edecrin(ethacrynic acid) and Lithium (lithium)
lithium and ethacrynic acid (Major Drug-Drug)
GENERALLY AVOID: Loop diuretics may increase serum lithium levels and potentiate the risk of lithium toxicity. The exact mechanism is unknown but may be related to the sodium loss induced by loop diuresis, which produces a compensatory increase in proximal tubular reabsorption of sodium along with lithium. Although a few studies using furosemide found no significant effect on serum lithium levels for up to 12 weeks of concomitant use, serious lithium toxicity has been reported, particularly in elderly patients. In a population-based case-control study of 10,615 patients older than 65 years who were receiving continuous lithium therapy for a total of 26,866 patient-years, 413 (4%) case patients were identified over a 10-year period who had at least one hospital admission for lithium toxicity. After adjustment for potential confounders, any exposure to a loop diuretic within the preceding 28 days of the episode was associated with a 1.7 relative risk of hospitalization for lithium toxicity compared to matched controls, and new exposure to a loop diuretic (defined as no other use of a loop diuretic in the preceding 365 days) was associated with a relative risk of 5.5. Overall, approximately 2.4% of all hospitalizations for lithium toxicity in this elderly cohort could be attributed to new use of a loop diuretic. There have also been individual case reports of patients developing lithium toxicity shortly after initiation of a loop diuretic. The risk for lithium toxicity may be further increased during concomitant sodium restriction.
MANAGEMENT: Loop diuretics should generally not be prescribed to patients receiving lithium unless close monitoring of serum lithium levels and electrolytes can be rendered. Lithium dose reductions may be required. Patients should be advised to notify their physician if they experience potential signs and symptoms of lithium toxicity such as drowsiness, dizziness, muscle weakness, vomiting, diarrhea, thirst, polyuria, tinnitus, tremor, ataxia, and blurred vision.
