Pharmacologic treatment of calcium calculi

Selective pharmacologic therapy of calcium nephrolithiasis is highly effective in preventing new stone formation. A remission rate of greater than 80 per cent and overall reduction in individual stone formation rate of greater than 90 per cent can be obtained in patients with calcium nephrolithiasis. In patients with mild-to-moderate severity of stone disease, virtually total control of stone disease can be achieved as evidenced by remission rates of greater than 95 per cent. The need for stone removal may be dramatically reduced by an effective prophylactic program. Selective pharmacologic therapy of calcium nephrolithiasis also encompasses the advantages of overcoming the nonrenal manifestations of conditions that cause stone formation as well as averting certain side effects that may be caused by nonselective medical therapy. Despite these advantages, selective medical therapy clearly cannot provide total control of stone disease. A satisfactory response requires continued, dedicated compliance by patients to the recommended program and a commitment of the physician to provide long-term follow-up and care.

The effectiveness of a cation resin (Kayexalate) as an adsorbent of paraquat: experimental and clinical studies

The cation-exchange-resin Kayexalate has an adsorption capacity for paraquat 15 times greater than activated charcoal and 6 times greater than Adsorbin. The oral LD50 of paraquat in rats rose 2.1 times by intragastric injection of Kayexalate. In the present study, the survival rate of rats given Kayexalate or Adsorbin after paraquat administration was examined. Results of clinical studies on 22 patients are also presented.

Management of antibiotic-associated pseudomembranous colitis

The diagnosis, etiology, epidemiology, and drug therapy of antibiotic-associated pseudomembranous colitis (AAPMC) are reviewed. AAPMC is an uncommon but potentially serious adverse reaction to therapy with almost any oral or injectable antibiotic and certain antineoplastic agents that alter intestinal flora. Proliferation of Clostridium difficile and subsequent release of clostridial cytotoxins cause pseudomembranous lesions and symptoms such as watery diarrhea, cramping abdominal pain, and low-grade fever. Symptoms can appear from four days after the start of antibiotic or antineoplastic therapy to 10 weeks after therapy has been discontinued. Drug therapy of AAPMC is directed at reducing the amount of Cl. difficile in the colon and promoting normalization of intestinal flora. Mild cases of AAPMC may respond to discontinuation of the etiologic agent and replacement of fluid and electrolytes. Therapy with an anticlostridial antibiotic is indicated in severe cases; although a seven- to 10-day course of oral vancomycin hydrochloride is the most widely recognized therapy, the drug is expensive and unpalatable. Good results have been reported with oral metronidazole and with bacitracin, both of which are less expensive than vancomycin. For all of these therapies, relapse rates are 20-39%. Anion exchange resins may be useful in mild cases of AAPMC. Successful management of AAPMC depends on a complex and ill-defined interrelationship between normal intestinal flora, patient immune response, antibiotic therapy, and the infecting clostridium strain. For moderate or severe cases of AAPMC, therapy should begin with metronidazole or bacitracin and vancomycin should be reserved for refractory cases, relapses, or patients with allergies to the other agents.

Resin hemoperfusion in hepatic porphyrias

In three types of hepatic porphyrias, 32 hemoperfusions over polyhema-coated Amberlite XAD-2 resin were performed. An attack of acute intermittent porphyria subsided after a 6-h hemoperfusion. During the procedure, 13 L of plasma was completely cleared of porphyrins. In a child with variegate porphyria, the laboratory changes were slight and no clinical effect of hemoperfusion was seen. In a patient suffering from porphyria cutanea tarda resistant to standard therapy, 30 hemoperfusions were performed during a period of 10 months. The total plasma porphyrin concentration increased sharply following the start of the treatment, and preceding the fifth procedure it reached a peak of four times the initial value. Since then, the plasma porphyrin level decreased, eventually to one-half the starting value. The mean drop in porphyrin level during each perfusion was 22%. Similar changes were observed in the amount of porphyrins excreted into the urine, which, following an early rise, decreased to 25% of the initial value. However, the patient's skin vulnerability improved only slightly. There were no untoward effects of the treatment.

Pseudohypoaldosteronism in a child with Down syndrome. Long-term management of salt loss by ion exchange resin administration

At 4 weeks of age, an infant with Down syndrome developed severe dehydration and salt loss with the typical features of pseudohypoaldosteronism (PHA). Plasma renin activity, 11-deoxycorticosterone, corticosterone and aldosterone levels were all increased several-fold over the normal range for age, thus excluding an adrenal biosynthetic defect. Clinical condition, hyponatraemia and hyperkalaemia could be rapidly normalised by the ion exchange resin Resonium A administered first as enema and later orally (3 g/day). At that time, no further salt supplementation was necessary. At 18 months of age, Resonium A could be completely withdrawn with neither clinical deterioration nor electrolyte abnormalities. However at 3 1/2 years of age, plasma renin activity and aldosterone were still markedly elevated while precursor steroids were normal and the clinical condition satisfactory. No side effects were observed with the Resonium A therapy. The combination of trisomy 21 and PHA is very unusual. Similarly, the successful treatment of severe renal salt loss during infancy by sodium supplementation and concomitant potassium withdrawal via an oral ion exchange resin has not yet been described and warrants further therapeutic trials.

[Acute renal insufficiency in children]

Acute renal failure (ARF) implies a sudden decrease in glomerular filtration rate with consequent retention of nitrogen waste products, water and electrolytes normally excreted by the kidney. The causes of ARF fall into three main groups: prerenal, intrinsic, and postrenal. Prerenal or functional failure can usually be controlled by simple therapeutic measures. If unrelieved, it leads to the development of renal parenchymal damage. Early biochemical indices are useful in distinguishing prerenal from intrinsic renal failure. Potentially reversible obstruction must be searched for by ultrasonographic and radiological procedures, and rapidly relieved. Symptoms of ARF result from disturbance of physiological regulatory functions. Prerenal failure requires urgent vascular expansion and careful monitoring of fluid and electrolyte replacement. Established renal failure demands careful management of electrolyte and water overload, metabolic acidosis, anemia, hypertension, infections and nutrition. Peritoneal dialysis or hemodialysis should be prepared for whenever severe hypertension, pulmonary edema or worsening biochemistry occur. Acute renal failure has a generally good prognosis if properly treated.

Cation exchange resin preparation in recurrent calcium urolithiasis

The efficacy of the cation exchange preparation, Campanyl, was studied in animal experiments and also in patients with absorptive hypercalciuria suffering from recurrent calcium stones, both in short-term studies on several treatment groups and with long-term maintenance dosage. In a dose of 15 Gm daily, taken with the main meal, the preparation was well tolerated and no serious side effects occurred. The frequency of stone passage, compared with that in the pretreatment period, was reduced by more than half, and urinary calcium excretion was considerably reduced. Litholysis was not observed. Campanyl is considered to be especially useful in patients with hyperabsorptive hypercalciuria. Dosage should be adjusted individually according to urinary calcium concentration.

[Long-term clinical experiences with the cation exchanger UJOLYT as a metaphylactic in absorptive hypercalciuria and chronic recurring calcium oxalate lithiasis]

The UJOLYT cation exchange was checked in a clinically controlled study over a long period using 6 male test persons with chronically recidive calcium oxalate lithiasis and absorptive hypercalciuria. The PAK calcium load test proved clinically valuable in the differentiation of idiopathic hypercalciuria. The paraclinical findings revealed an average reduction of urinary calcium excretion by 40% and an increase of urinary magnesium excretion by 11.7% compared to the initial situation. The recidive frequency was clearly reduced. No serious side-effects were observed in the patients presented.

The effects of cholestyramine, colestipol, and ADR-132 on the rat prostate and dunning R-3327 adenocarcinoma

The effects of three compounds known to have hypocholesterolemic activity in several species were investigated on the rat prostate and the hormone-dependent R-3327 rat prostatic adenocarcinoma. Cholestyramine, colestipol, and ADR-132 are bile acid-sequestering anion exchange resins which were fed to separate groups of adult male Copenhagen X Fischer (F1) hybrid rats in doses of 0.25%, 1.00%, and 2.00% of diet. The results indicate that serum cholesterol levels in tumor-bearing rats and controls fed these compounds for 29 days were not reduced. The body and organ weights as well as the histological features of the prostate gland, seminal vesicles, and the R-3327 tumor were unaffected by these agents.

Preparation of a biocompatible albumin-coated ion exchange resin for bilirubin removal from the blood of jaundiced newborns

Removal of bilirubin by hemoperfusion with ion exchange resin particles is suggested to replace exchange transfusion of blood of jaundiced infants in some cases of unconjugated hyperbilirubinemia. The hemoperfusion system developed here consists of a packed bed of a macroreticular resin which is made biocompatible by a coating of a monomolecular layer of albumin. The choice of the appropriate ionic form of the resin and the proper albumin coating and crosslinking procedure assures a high bilirubin adsorption capacity and excellent blood compatibility of the resin. The albumin coated resin removes in vitro 80-90% of the bilirubin initially present in the plasma. The results encourage in vivo clinical studies.