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Biomedical subjects

A Salvadeo

Publications and source records attributed to A Salvadeo.

At least 37 records · Page 2Linked to original sources
PubMed1988

Efficacy and safety of long-term treatment with calcium carbonate as a phosphate binder.

The efficacy and safety of calcium carbonate as a phosphate binder was evaluated in 20 patients on chronic hemodialysis who had previously received aluminum hydroxide. During the control period the patients were on aluminum hydroxide and calcitriol therapy and had plasma phosphorus levels less than 6 mg/dL (4.95 +/- 0.8 mg/dL). Aluminum hydroxide was then discontinued and no phosphate binder was prescribed for 1 month. Every patient developed hyperphosphatemia so that calcium carbonate treatment was begun and calcitriol dose was adjusted in relation to plasma calcium changes. After 24 months of calcium carbonate therapy, plasma phosphorus was 4.85 +/- 0.7 mg/dL, using a daily dose of calcium carbonate of 2.57 +/- 1.3 g (range, 1 to 6 g). The daily dose per patient of calcitriol was not different from that prescribed during the control period, but in five patients calcitriol was permanently withdrawn for hypercalcemia. At the end of the study plasma calcium, magnesium, bicarbonate, alkaline phosphatase, and parathyroid hormone values were unchanged in comparison with the control period, whereas a significant reduction in plasma aluminum and plasma aluminum increase induced by deferoxamine infusion was observed. The frequency of hypercalcemic and hyperphosphatemic episodes during the last 12 months of calcium carbonate therapy (6.2% and 16.6%, respectively) was not different from that observed during the 12 months on aluminum hydroxide therapy preceding the control period (4.5% and 14.7%, respectively). It was concluded that calcium carbonate is effective in the control of hyperphosphatemia and secondary hyperparathyroidism in patients on chronic hemodialysis and that the incidence of hypercalcemia is low when the daily dosage is less than 6 g.

Adult↗
PubMed1988

Pharmacokinetics of teicoplanin in the elderly.

The pharmacokinetic profile of teicoplanin was studied in 12 elderly patients with a moderate degree of renal impairment (mean creatinine clearance, 51.3 ml/h/kg before treatment), after a single 6 mg/kg iv dose. Pharmacokinetic parameters were estimated both by a three-compartment open pharmacokinetic model and by non-compartmental analysis; peak plasma levels, 15 min after administration, averaged 45 mg/l. The half-lives of two distributive phases were 0.39 and 7.3 h, respectively. The elimination half-life averaged 107 h, with similar estimates obtained from the three-compartment analysis and from urinary data. The volume of distribution from the central compartment was 0.09 l/kg while the volumes of distribution at steady state and during the elimination phase were 1.3 and 1.6 l/kg, respectively. The total teicoplanin clearance averaged 10.6 ml/h/kg, with renal clearance accounting for about 40% of the total. There was a linear correlation between teicoplanin total or renal clearance and endogenous creatinine clearance. The average total recovery of teicoplanin in urine over eight days was 28%. There were no local or systemic adverse reactions to teicoplanin.

Aged↗
PubMed1988

Effects of ibopamine in combination with furosemide on renal function in patients with chronic congestive heart failure.

The effects of ibopamine and furosemide on renal function given alone and in combination at single doses were studied in 6 men and 6 women aged 45 to 73 years with chronic congestive heart failure of NYHA class II. After 3 days of dietary stabilization, the patients received either ibopamine 200 mg, furosemide 40 mg, or furosemide 40 mg plus ibopamine 200 mg with 2-day washout between treatments, according to a double-blind, balanced three-way crossover design using all possible treatment sequences. On each treatment day urine collections were performed at 2-hourly intervals from 2 h before to 6 h after dosing, and urine volume and Na+, K+, Cl-, and creatinine concentrations were measured for every period. The patients received a standardized breakfast 3 h before treatment and then were allowed 250 ml tap water to drink before starting each urine collection period. Venous blood samples were taken before breakfast and midway between each urine collection period for analysis of serum Na+, K+, Cl-, creatinine, and glucose. Heart rate, blood pressure, and physical signs were recorded 2, 1 h, immediately before, and then 0.5, 1, 2, 3, 4, 5, and 6 h after treatment. At the same times the patients were asked for any symptoms. The time course of the diuretic effect of furosemide 40 mg was consistent with the data reported by other authors.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Pharmacokinetics of ibopamine in patients with renal impairment.

The pharmacokinetics of a single oral dose of ibopamine 100 mg were studied in 15 patients with various degrees of chronic renal impairment (CRI) and in 8 subjects with normal renal function and of comparable age, taken as a control group. Plasma total (mainly conjugated) and free epinine and urinary metabolites (total epinine, HVA and DOPAC) were measured. Both total and free epinine were detectable at the earliest sampling time (15 min) in CRI patients and in normal subjects, thus confirming the promptness of ibopamine absorption. Free epinine pharmacokinetic parameters did not show any appreciable differences among the groups with different degrees of renal impairment, and no statistically significant differences were observed between normal subjects and CRI patients. Progressive renal impairment was associated with higher Cmax, longer t1/2 and larger AUC infinity of total epinine, and with reduced urinary elimination of total epinine and metabolites. Statistically significant differences (p less than 0.01) in Cmax/70 kg, t1/2, and AUC infinity/70 kg of total epinine were found between normal subjects and patients with mild renal impairment. No statistically significant differences were observed in 24-h urinary recoveries of both total epinine and metabolites between normal subjects and patients with mild renal impairment. No adverse effects were experienced during the course of the study. As the kinetics of ibopamine's active moiety, free epinine, were not apparently altered by chronic renal failure, adjustment of its dosage should not be necessary in renal diseases.

Adolescent↗
PubMed1987

Teicoplanin pharmacokinetics in patients with chronic renal failure.

The pharmacokinetic profile of teicoplanin, a new glycopeptide antibiotic active against Gram-positive aerobic and anaerobic bacteria, was studied in 5 healthy male volunteers and 29 adult patients with various degrees of renal impairment, given a single 3 mg/kg intravenous dose. Teicoplanin was assayed in plasma and urine specimens by a microbiological method. Pharmacokinetic parameters for teicoplanin were estimated both by a 3-compartment open pharmacokinetic model and by non-compartmental analysis. Elimination half-life increased with the decrease in creatinine clearance and mean values ranged from 41 hours in volunteers to 163 hours in anuric patients. Renal failure did not affect either the volume of distribution of the central compartment (mean approximately 0.09 L/kg) or the steady-state volume of distribution (mean approximately 0.9 L/kg). Both total and renal clearance decreased with severity of disease, particularly the latter, while non-renal clearance was unaffected by renal failure. Average values were from 19 to 6 ml/min for total clearance and from 12 to 0.4 ml/min for renal clearance. There was a linear correlation between the total clearance of teicoplanin and creatinine clearance, as well as between renal clearance and creatinine clearance. The total urinary excretion of active teicoplanin averaged 65% of the administered dose in normal subjects, but was significantly reduced in the presence of renal insufficiency. Guidelines for administration of teicoplanin in patients with renal failure are given.

Adult↗
PubMed1986

Assessment of split renal function with 99mTc-aprotinin.

The aim of this work is to correlate the net kidney uptake of 99mTc-aprotinin (TcA) in 103 subjects with separate effective renal plasma flow (ERPF) and some blood chemistry parameters at 90, 180, and 360 min postinjection both in the normal and diseased kidney. Correlations found with separate ERPFs are highly significant at any time (P less than 0.001). However, although the slope of the regression line is steeper at 180 min, r tends to deteriorate slightly with time postinjection and a higher intercept on the y axis; this pattern is more pronounced if diseased kidneys are considered separately. The following are probably related to the renal handling of TcA: Early scans better reflect blood flow to the kidney, while later scans are more related to the metabolism/excretion tubular mechanisms; correlations found with urea, creatinine, urea clearance, and creatinine clearance are highly significant at any time; in 20 additional patients with diseased kidneys, renal uptake measurements done 360 min postinjection first with TcA and then with DMSA showed better correlations with ERPF employing TcA. Our results indicate that TcA is a feasible indicator of split renal function even at 90 min postinjection when a scan is easily carried out on an outpatient basis.

Adolescent↗
PubMed1986

Acid-base balance and respiratory response during biofiltration with polyacrylonitrile membrane.

To further elucidate the mechanisms responsible for the hypoxemia we studied ventilation, pulmonary gas exchanges, blood gas pressures and exchanges of CO2-T, CO2-D and HCO-3 in six patients during AD and BD on 1 m2 cuprophan filter and during BF on 1.2 m2 polyacrylonitrile filter. Blood passing through the dialyzer lost 172.8 mM/h of CO2-T in AD, 149.2 mM/h in BF and gained 25.6 mM/h in BD. In AD VE, VA and PaO2 decreased significantly after 30 and 60 min., in BF for the whole duration of dialysis. PoO2 showed a significant decrease both in AD and BF after 60 min. In AD PaCO2 was significantly reduced after 120 and 180 min. All the above parameters remained unchanged in BD. VCO2 remained unchanged in all. VCO2 and R decreased both in AD and BF. However, when VCO2 was corrected for CO2 loss across the dialyzer, overall CO2 loss (ventilated plus filtered) and R returned to basal values. In AD, HCO-3 and pH fell in the first 120 min., while in BD and BF they increased from the beginning of dialysis. In AD hypoventilation, hypoxemia and inadequate correction of acid-base balance were due to the loss of HCO-3 across the filter. In BF also hypoventilation and hypoxemia were due to the loss of HCO-3 across the filter but the acid-base balance was adequately corrected by HCO-3 reinfusion. In BD, there was HCO-3 gain across the filter which induced a gradual correction of acid-base balance without impairment of ventilation.

Acid-Base Equilibrium↗
PubMed1985

Cadralazine, a new vasodilator, in addition to a beta-blocker for long-term treatment of hypertension.

51 hypertensive outpatients, whose diastolic blood pressure exceeded 100 mmHg after a 2-week period on atenolol alone (100 mg once daily) participated in this long-term study. They received, in addition to atenolol, the vasodilator cadralazine (ISF 2469; 10 to 30 mg once daily) for a standard period of 24 weeks, according to an open design. Cadralazine caused a progressive and important decrease in both systolic and diastolic blood pressure, from 173/111 mmHg (end of atenolol alone) to 154/99 mmHg (12th week, p less than 0.01/p less than 0.01; mean dose, 24.5 mg/day). At this time a diuretic was added as a third-step drug in 15/51 initial patients (29%), and final blood pressure in all patients was 150/96 mmHg (p less than 0.01/p less than 0.01), with positive results in 88% of the cases. During cadralazine treatment, heart rate was always significantly lower than before atenolol alone; the most common side effects, many of which were already present during treatment with atenolol alone, included headache, asthenia, dizziness, palpitation and flushing, and tended to disappear spontaneously as therapy progressed. Routine laboratory tests did not show important changes; sodium excretion was not reduced. In conclusion, the therapeutic efficacy of cadralazine, its low or absent salt and water retention effects, its good tolerability, and the high compliance obtained with once daily administration allowed the use of this vasodilator as a second-step drug for long-term treatment of hypertension.

Adrenergic beta-Antagonists↗
PubMed1983

A crossover trial of oxdralazine in hypertension.

Twenty-nine moderate and severe essential hypertensive patients completed a crossover study aimed at evaluating efficacy and tolerability of a double combination (chlorthalidone plus propranolol) and of a triple combination (chlorthalidone plus oxdralazine plus propranolol). After one month on 25 mg/day chlorthalidone, which caused nonsignificant reduction in blood pressure of 7/4 mm Hg, patients were randomized to receive either the double or triple regimen for a three-month period. Then, after another month on chlorthalidone alone at the same dose of 25 mg/day, treatments were crossed over and the study continued for another three-month period. The double regimen caused a drop in pressure of 16/11 mm Hg after one month (daily doses 25 mg chlorthalidone, 103 +/- 25 mg propranolol), and this reduction did not change at the third month in spite of dosage increases (daily doses 25 mg chlorthalidone, 222 +/- 77 mg propranolol). The triple regimen reduced blood pressure 35/15 mm Hg after one month (daily doses 25 mg chlorthalidone, 20 mg oxdralazine, 40 mg propranolol), and further increase in dosages caused a reduction of 45/24 mm Hg at the third month (daily doses 25 mg chlorthalidone, 56 +/- 20 mg oxdralazine, 112 +/- 40 mg propranolol). Both treatments were well tolerated; in particular, at the end of the third month of each treatment period, 25 patients on the triple regimen achieved a stable diastolic blood pressure of 90 mm Hg or less, as compared to 10 patients on the double regimen (P less than 0.01).

Adult↗
PubMed1983

[Respiratory response and acid-base equilibrium in acetate dialysis and bicarbonate dialysis].

In order to elucidate the mechanisms responsible for the hypoxemia observed during acetate dialysis, but not found during bicarbonate dialysis, the authors studied ventilation, blood gases and their exchanges in the lungs and across the dialyzer on 9 patients. Oxygen consumption was similar both in acetate and bicarbonate dialysis. At the beginning of acetate dialysis, hypocapnia, due to CO2 losses through the dialyzer, causes hypoventilation and hypoxemia; afterwards, the worsening of acidosis (due to bicarbonate losses) stimulates ventilation, thus correcting the initial imbalance. Authors also hypothesize a pulmonary mechanism for CO2 "sparing" contributing to compensate CO2 losses through the dialyzer. The absence of hypoxemia during bicarbonate dialysis would be due to the absence of CO2 losses through the dialyzer.

Acetates↗
PubMed1983

Pressure and humoral changes induced by atenolol and hydrochlorothiazide + amiloride, alone and in free combination. A comparative between-patient study.

The authors have performed a between-patient study in 76 patients with mild or moderate essential arterial hypertension, with the aim of comparing the results of atenolol 100 mg daily, hydrochlorothiazide 50 mg + amiloride 5 mg 1 tablet daily, and the combination of the above two agents at the same daily doses. Thirty-one patients received the free combination diuretic-beta-blocker throughout the study period; 26 patients non-responders to atenolol 100 mg daily (supine diastolic blood pressure greater than 90 mmHg) after a one-month treatment period received the above combination for a further four months; and 19 patients non-responders to hydrochlorothiazide 50 mg + amiloride 5 mg, 1 tablet daily, after a one-month treatment period received the above combination for a further four months. In the patients who were non-responders to either atenolol or the diuretic, supine and upright blood pressure showed a further and clinically consistent decrease as a result of the combination therapy. A similar consistent decrease was seen in the patients receiving the combination therapy throughout the study. Plasma levels of glucose, urea, creatinine, sodium, potassium and uric acid were not modified either by the single agents or during administration of the combination therapy. In particular, plasma potassium concentration did not show any statistical or clinical changes. Any side-effects were of little clinical importance and never required discontinuation of therapy. In conclusion, atenolol combined with hydrochlorothiazide + amiloride (100 mg + 50 mg + 5 mg) provides an effective and well tolerated blood pressure control in most patients with mild or moderate arterial hypertension, including non-responders to diuretic or beta-blocker alone.

Adult↗