Successful Management of Refractory Type 1 Renal Tubular Acidosis with Amiloride

Abstract

A 28-year-old female with history of hypothyroidism, Sjögren's Syndrome, and Systemic Lupus Erythematosus (SLE) presented with complaints of severe generalized weakness, muscle pain, nausea, vomiting, and anorexia. Physical examination was unremarkable. Laboratory test showed hypokalemia at 1.6 mmol/l, nonanion metabolic acidosis with HCO3 of 11 mmol/l, random urine pH of 7.0, and urine anion gap of 8 mmol/l. CT scan of the abdomen revealed bilateral nephrocalcinosis. A diagnosis of type 1 RTA likely secondary to Sjögren's Syndrome was made. She was started on citric acid potassium citrate with escalating dosages to a maximum dose of 60 mEq daily and potassium chloride over 5 years without significant improvement in serum K+ and HCO3 levels. She had multiple emergency room visits for persistent muscle pain, generalized weakness, and cardiac arrhythmias. Citric acid potassium citrate was then replaced with sodium bicarbonate at 15.5 mEq every 6 hours which was continued for 2 years without significant improvement in her symptoms and electrolytes. Amiloride 5 mg daily was added to her regimen as a potassium sparing treatment with dramatic improvement in her symptoms and electrolyte levels (as shown in the figures). Amiloride was increased to 10 mg daily and potassium supplementation was discontinued without affecting her electrolytes. Her sodium bicarbonate was weaned to 7.7 mEq daily.

Distal renal tubular acidosis and severe hypokalemia: a case report and review of the literature

“…Our patient was treated with K + and sodium bicarbonate supplementation to correct her acid-base imbalance. She also received amiloride as recent literature suggests that patients with severe disease may respond to this therapy [28]. Amiloride inhibits electrogenic sodium transport through the epithelial sodium channel in the principal cells and thus decreases the driving forces for electrogenic potassium secretion [28].…”

“…She also received amiloride as recent literature suggests that patients with severe disease may respond to this therapy [28]. Amiloride inhibits electrogenic sodium transport through the epithelial sodium channel in the principal cells and thus decreases the driving forces for electrogenic potassium secretion [28]. On follow-up, she maintained mild hypokalemia (K + , 3.1–3.4 mEq/L) as well as mild metabolic acidosis (HCO 3 − , 19–23 mmol/L).…”

Rickets Secondary to Distal Renal Tubular Acidosis: A Rare Case Report

“…The hypokalemia should be managed by potassium supplementation and a potassium sparing diuretic like spironolactone, triametrene or amiloride. [10] Rickets seen in distal tubular acidosis can be treated by calcium and vitamin D supplementation along with correction of primary metabolic abnormality (acidosis and hypokalemia).…”

Renal tubular acidosis in pediatrics: A review article

“…34 A case of Sjogren's syndrome refractory type 1 renal tubular acidosis was treated by sodium bicarbonate 15.5mEq four times a day, potassium chloride and amiloride 10mg/day. 11 With treatment of nephrocalcinosis underlying causes, symptoms will resolve. 12 Latest research precludes that disruption of the COPI-kAE1 G701D interaction could be a therapeutic strategy to treat dRTA caused by this mutant.…”

“…Its suppression results in dilution of urine which is caused by lysosomal defect in vH+ATPase channel. 10,11 2-Acquired cases as they are secondary to immunemediated diseases. Most common association is with Sjogren's syndrome and with kidney stones.…”