Hyperkalemic metabolic acidosis

Amiloride Blocks epithelial sodium channels in collecting tubules Reduces Na retention and wasting increases lithium clearance Hypokalemia from other diuretics reduces lithium-induced polyuria Orally active duration 24 h Toxicity Hyperkalemic metabolic acidosis... 

A 47-year-old woman had an infusion of propofol 200 micrograms/kg/minute for 4 days. On day 2 she developed hematuria, and laboratory investigations showed renal insufficiency with hyperkalemic metabolic acidosis. She died as a result of rhabdomyolysis with cardiac involvement. 

B. Effects All three drugs in this class cause an increase in sodium clearance and a decrease in potassium and hydrogen ion excretion and therefore qualify as potassium-sparing diuretics. They may cause hyperkalemic metabolic acidosis (Table 15-2). 

The metabolic acidosis associated with hyperkalemic distal (type IV) RTA with hyporeninemic-hypoaldosteronemia that is often seen in patients with diabetes meUitus may be corrected by the treatment of hyperkalemia alone (see Chap. 50). The use of supplemental alkali (1 to 2 mEq/kg per day) to increase sodium intake and stimulate distal tubular potassium secretion may be beneficial. A minority of patients require the administration of pharmacologic amounts of fludrocortisone." Type TV RTA resulting from a generalized distal tubular disorder often responds to low doses of alkali (1.5 to 2.0 mEq/kg per day). ° Corrections of the acidosis along with modest dietary potassium restriction (to 1 mEq/kg per day) wfll often result in the maintenance of serum potassium levels of 5 mEq/L or less. 

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