enalapril and Acidosis

To evaluate the efficacy and safety of losartan and enalapril in pediatric kidney transplant recipients.. A retrospective review was performed in 31 pediatric kidney transplant recipients who were treated with losartan (50 mg/d, oral) for 1 to 6 months because of mild hypertension and persistent proteinuria. All patients were treated concurrently with enalapril (5 or 10 mg daily, oral), and 12 patients (39%) also were treated with amlodipine (5 or 10 mg daily, oral). Demographic and clinical characteristics of the patients were reviewed.. Losartan use was associated with a significant decrease in mean systolic (before losartan was started, 123 ± 14 mm Hg; before losartan was stopped, 111 ± 10 mm Hg; P ≤ .001) and diastolic blood pressure (before losartan was started, 78 ± 11 mm Hg; before losartan was stopped, 69 ± 10 mm Hg; P ≤ .001) and urinary protein excretion (before losartan was started, 51 ± 45 mg/m2/h; before losartan was stopped, 28 ± 34 mg/m2/h; P ≤ .001). However, losartan therapy was associated with a significant mean increase in serum potassium level (before losartan was started, 4.0 ± 0.4 mmol/L; before losartan was stopped, 5.7 ± 0.5 mmol/L; P ≤ .001) and decrease in pH (before losartan was started, 7.35 ± 0.0; before losartan was stopped, 7.23 ± 0.0; P ≤ .001). Losartan was stopped because of hyperkalemia and acidosis earlier in patients who were on tacrolimus than cyclosporine immunosuppression (tacrolimus, 3 ± 1 mo; cyclosporine, 4.7 ± 0.8 mo; P ≤ .001).. Losartan and enalapril may be beneficial in pediatric kidney transplant recipients by decreasing blood pressure and proteinuria, with maintenance of stable graft function, but may be associated with serious adverse events including hyperkalemia and life-threatening acidosis.

Topics: Acidosis; Adolescent; Age Factors; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Biomarkers; Blood Pressure; Child; Child, Preschool; Drug Therapy, Combination; Enalapril; Female; Humans; Hydrogen-Ion Concentration; Hyperkalemia; Hypertension; Kidney Transplantation; Losartan; Male; Potassium; Proteinuria; Retrospective Studies; Risk Factors; Time Factors; Treatment Outcome

Angiotensin II stimulates the proximal tubular Na/H antiporter and increases proximal tubular cell pH. Because intracellular pH may affect urinary citrate excretion and enzymes responsible for renal citrate metabolism, the present studies examined the effect of enalapril, an angiotensin converting enzyme inhibitor, on the activity of renal cortical ATP citrate lyase and urinary citrate excretion.. Enalapril was given to rats (15 mg/kg/day) for seven days and to humans (10 mg twice daily) for 10 days. Blood and 24-hour urine samples were obtained in both groups. Renal cortical tissue from rats was analyzed for enzyme activity.. In rats, enalapril decreased urinary citrate excretion by 88%. The change in urinary citrate was not associated with a difference in plasma pH, bicarbonate nor potassium concentration. However, similar to metabolic acidosis and hypokalemia, enalapril caused a 42% increase in renal cortical ATP citrate lyase activity. When given to humans, enalapril significantly decreased urinary citrate excretion and urine citrate concentration by 12% and 16%, respectively, without affecting plasma pH or electrolytes.. Enalapril decreases urinary citrate in rats and humans. This is due, at least in part, to increases in cytosolic citrate metabolism through ATP citrate lyase in rats similar to that seen with chronic metabolic acidosis and hypokalemia. The effects of enalapril on urinary citrate and renal cortical ATP citrate lyase occur independently of acidosis or hypokalemia but may be due to intracellular acidosis that is common to all three conditions.

Topics: Acidosis; Adult; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Citric Acid; Enalapril; Female; Humans; Hypokalemia; Male; Rats; Rats, Sprague-Dawley

A 71 year old hypertensive, non insulin-dependent diabetic patient with moderate renal insufficiency taking 500 mg/d of metformin and 5 mg/d of enalapril, developed metabolic acidosis characterized by fairly elevated anion gap, hyperchloremia, severe hyperkaliemia, normal plasma level of 3-hydroxybutyric acid, absence of ketonuria and high plasma level of lactic acid. This biochemical feature allowed us to ascribe the pathogenesis of metabolic acidosis, both to the increased plasma level of lactic acid and to the type IV renal tubular acidosis syndrome, the precipitating factor being an infection of urinary tract (as we assumed on the basis of the urine culture). The patient was dehydrated and lethargic; the ECG revealed the presence of nonparoxysmal junctional tachycardia. The clinical evolution was favorable under the treatment with an infusion of isotonic saline solutions, mild alkalinizing solutions, low-dose regular insulin and antibiotics. It is likely that metformin and enalapril, regularly taken by this nephropathic patient, could have played an iatrogenic role, even if the doses were low. This case highlights the importance of complying with the contraindications of these drugs, to avoid the rare but reported life-threatening complications of metformin administration.

Topics: Acidosis; Aged; Antihypertensive Agents; Chlorides; Diabetes Mellitus, Type 2; Drug Synergism; Drug Therapy, Combination; Enalapril; Female; Humans; Hypertension; Hypoglycemic Agents; Lactic Acid; Metformin