Medication Summary
Therapy for patients with acute poststreptococcal glomerulonephritis is symptomatic in nature and depends on the clinical severity of the illness. The major aims are to control the edema and blood pressure.
During the acute phase of the disease, salt and water should be restricted. If significant edema or hypertension develops, diuretics should be administered. Loop diuretics increase urinary output and consequently improve cardiovascular congestion and hypertension.
For hypertension not controlled by diuretics, calcium channel blockers or angiotensin-converting enzyme inhibitors are generally useful. For malignant hypertension, intravenous nitroprusside or other parenteral agents are used.
The indications for dialysis include life-threatening hyperkalemia and clinical manifestations of uremia. Steroids, immunosuppressive agents, and plasmapheresis are not generally indicated. In patients with rapidly progressive renal failure, a kidney biopsy is indicated. If the biopsy findings show evidence of crescentic glomerulonephritis with more than 30% of the glomeruli involved, a short course of intravenous pulse steroid therapy is recommended (500 mg to 1 g/1.73 m2 of methylprednisone qd for 3-5 d). However, no controlled clinical trials have evaluated such therapy. Long-term treatment with steroids or immunosuppressives is not recommended.
Diuretics
Class Summary
Used to control edema and circulatory congestion.
Furosemide (Lasix)
Increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in ascending loop of Henle and distal renal tubule. Dose must be individualized to patient. Depending on response, administer at increments of 20-40 mg, no sooner than 6-8 h after the previous dose, until desired diuresis occurs. When treating infants, titrate with increments of 1 mg/kg/dose until a satisfactory effect is achieved.
Calcium channel blockers
Class Summary
In specialized conducting and automatic cells in the heart, calcium is involved in the generation of the action potential. Calcium channel blockers inhibit movement of calcium ions across the cell membrane, depressing both impulse formation (automaticity) and conduction velocity.
Amlodipine (Norvasc)
Relaxes coronary smooth muscle and produces coronary vasodilation, which, in turn, improves myocardial oxygen delivery. Benefits nonpregnant patients with systolic dysfunction, hypertension, or arrhythmias. Can be used during pregnancy if clinically indicated.
Angiotensin-converting enzyme inhibitors
Class Summary
Decrease aldosterone secretion.
Captopril (Capoten)
Prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in lower aldosterone secretion.
Enalapril (Vasotec)
Competitive inhibitor of angiotensin-converting enzyme. Reduces angiotensin II levels, decreasing aldosterone secretion. Clinical response usually observed within 15 min of administration.
Vasodilators
Class Summary
Used to treat hypertensive emergencies. Vasodilators reduce SVR, which, in turn, may allow forward flow, improving cardiac output.
Nitroprusside (Nitropress)
Produces vasodilation and increases inotropic activity of heart. At higher dosages, may exacerbate myocardial ischemia by increasing heart rate. Should not be used to treat compensatory hypertension (arteriovenous shunt or coarctation of aorta).
Hydralazine (Apresoline)
Decreases systemic resistance through direct vasodilation of arterioles.
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Kidney biopsy from a 7-year-old child with acute poststreptococcal glomerulonephritis. Periodic acid–Schiff stain (at 40x) shows the intracapillary and occasional mesangial neutrophil (arrows). Courtesy of Laura Kidd, MD, Pathology and Laboratory Medicine, Tulane University Medical School.
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Kidney biopsy from a 7-year-old child with acute poststreptococcal glomerulonephritis. Periodic acid–Schiff stain (at 40x) shows the intracapillary and occasional mesangial neutrophil (arrows). Courtesy of Laura Kidd, MD, Pathology and Laboratory Medicine, Tulane University Medical School.
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Kidney biopsy from a 7-year-old child with acute poststreptococcal glomerulonephritis. Electron microscopy image shows rare large subepithelial deposits, or “humps” (arrows). Courtesy of Laura Kidd, MD, Pathology and Laboratory Medicine, Tulane University Medical School.
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Kidney biopsy from a 7-year-old child with acute poststreptococcal glomerulonephritis. Electron microscopy image shows rare large subepithelial deposits, or “humps” (arrows). Courtesy of Laura Kidd, MD, Pathology and Laboratory Medicine, Tulane University Medical School.
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Kidney biopsy from a 7-year-old child with acute poststreptococcal glomerulonephritis. Immunofluorescence (C3) shows a granular capillary and mesangial staining pattern with segmental areas of “lumpy-bumpy” staining (white arrows). Courtesy of Laura Kidd, MD, Pathology and Laboratory Medicine, Tulane University Medical School.
