Osvaldo Ramirez

Creatinine clearance in renal disease. A reappraisal

To determine the validity of endogenous creatinine clearance as a measure of glomerular filtration rate in patients with renal disease 308 simultaneous determinations of inulin clearance and endogenous creatinine clearance were reviewed and analysed. The ratio of creatinine clearance/inulin clearance increased progressively with the decline in inulin clearance, while the finding of a normal endogenous creatinine clearance masked a definite but mild decrease of glomerular filtration rate in 42% of the patients and a moderate decrease of glomerular filtration rate in 23%. This indicates that with declining glomerular filtration rates the endogenous creatinine clearance progressively overestimates actual glomerular filtration rates. Hence a single determination of creatinine clearance can be misleading as a screening measurement of glomerular filtration rate.

Acute renal failure after administration of low-molecular weight dextran.

THE infusion of low-molecular-weight dextran (Dextran 40) has been associated with acute renal failure in 14 patients.14 Three of these cases, not previously reported but submitted to Pharmacia Lab...

Serum and erythrocytic magnesium levels in congestive heart failure

Abstract Pretreatment serum and erythrocytic magnesium levels were found to be significantly lower in patients with congestive heart failure than in control subjects. The erythrocytic sodium level also was lower. The low magnesium and sodium values may be the result of a dilutional intracellular effect or may reflect long term diuretic therapy and possibly diets low in magnesium and sodium. The administration of hydrochlorothiazide did not significantly affect serum or erythrocytic cation levels. Absence of the expected decrease in serum magnesium subsequent to the administration of hydrochlorothiazide may be due to the fact that the pretreatment serum levels were significantly lower than in normal subjects. It is suggested that, in patients with congestive heart failure, low serum and intracellular magnesium levels may contribute to the development of digitalis toxicity, even in the presence of normal serum potassium levels. Although the patients with congestive heart failure were normotensive, changes in diastolic blood pressure induced by hydrochlorothiazide correlated with changes in serum magnesium as well as with changes in the ratio of erythrocytic potassium to serum magnesium.

Pharmacodynamic effects of a new diuretic drug, ethacrynic acid∗

Abstract Ethacrynic acid is an extremely potent diuretic and natriuretic agent. Its rapid onset of action following intravenous administration suggests particular usefulness in patients with severe cardiac decompensation, e.g., acute pulmonary edema. Furthermore, the parenteral drug appears to be effective despite reduced glomerular filtration rates, and, therefore, may be useful in the treatment of edema associated with advanced renal functional impairment. Oral administration of ethacrynic acid also results in potent diuretic activity, with substantial antihypertensive effectiveness as well. The oral compound compares favorably with other potent oral diuretics and with parenteral meralluride.

Clinical selection of diuretic drugs in the management of cardiac edema

Abstract Mild cardiac edema can usually be controlled with a thiazide diuretic or a related sulfonamide compound. Successful treatment of moderate or severe heart failure generally requires (1) more potent diuretic drugs used alone, or (2) a combination of diuretic agents, such as ethacrynic acid or furosemide combined with a potassium-sparing drug or thiazide diuretic, or both. Regardless of the regimen employed, the efficient use of these various diuretic agents requires an intimate familiarity with their clinical pharmacology.

Hemodynamic Effects of Pargyline in Hypertensive Patients

Pargyline exerts its antihypertensive effect via a predominant reduction in peripheral vascular resistance, whereas cardiac output is not altered significantly. The effect on renal blood flow is inconsistent, but a significant reduction in glomerular filtration rate does occur. Therefore the drug should be used with appropriate caution in patients with significant impairment of renal function. The hemodynamic response observed with pargyline is similar to that obtained with other MAO inhibitors.

Hemodialysis for Methyprylon (Noludar®) Poisoning

Abstract A case of methyprylon (Noludar®) poisoning treated with extracorporeal hemodialysis is reported. The patient showed dramatic clinical improvement with concomitant lowering of serum methypr...

Radiological Contrast Study of Arteriovenous Dialysis Cannulae

Abstract Radiographic contrast studies of shunts are helpful in defining the causes of cannula dysfunction. X -ray examination has confirmed the presence of thrombi and revealed the adequacy of declotting procedures, indicating circumstances under which such techniques should be avoided. Radiographic studies provide a sound anatomical basis for the selection of shunt sites. Dilute contrast media are recommended.

Refractory heart failure. Differential diagnosis and management.

A patient with congestive heart failure whose remediable problems do not respond to routine therapeutic measures may be said to have refractory heart failure. Such a patient usually requires a combination of a potent diuretic and one or more potentiating agents such as aminophylline, an acidifying drug, prednisone or an aldosterone-blocking agent. Combinations of five or more diuretic agents with different pharmacodynamics can be used effectively.