[Dosage of nalidixic acid. Value of a pharmacokinetic study].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to N Pozet.
Explore the source record for details and available documents.
Labetalol, a blocker of alpha- and beta-adrenoreceptors, was tried on 45 patients with severe (29 cases) or mild to moderate (16 cases) hypertension. After an initial period of dosage adjustment and a 2 months treatment in effective doses, there was a significant fall in supine blood pressure from mean values of 207/132 to 170/106 mmHg. In 23 patients hypertension was controlled by labetalol alone in doses of 400 and 1800 mg per day. True failures were rare (16%). Digestive disorders and postural hypotension were the most frequently encountered side-effects; they obliged to discontinue treatment in 4 cases, but were compatible with it in 11 cases. In 22 patients the fall in BP was accompanied by a significant (p less than 0,001) decrease in plasma renin activity from 123 to 44 ng/l/min supine and from 144 to 83 ng/l/min standing. Studies of the renal function showed no changes during oral therapy. Following intravenous injection of 50 mg labetalol to 20 subjects, inulin and PAH clearances remained unaltered, and there was a significant, though transient (1 hour), decrease in chloride, sodium and phosphorus excretion. Effective in lowering blood pressure be used and well tolerated by the kidneys, labetalol can safely be used for the treatment of severe hypertension with organic renal involvement.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1 The pharmacological actions of piretanide, a new high efficiency diuretic, were studied in sixteen patients with GFR (inulin clearance) varying from 0.1--2.5 ml/s. 2 After hydration and following two control periods, a single dose of 6 mg piretanide was ingested. Thereafter, urine was collected every 30 min for 2 h and every hour for the next 4 h. Fluid losses were replaced. 3 The following measurements were made: urine flow rate, clearances of inulin, PAH, urea, creatinine, uric acid, osmolar and free water clearances, excretion rates of sodium, chloride, potassium, calcium, phosphate, bicarbonate, ammonium, titratable acidity and urine pH. 4 Main results showed piretanide was efficient in the group with normal GFR (inulin clearance greater than 1.5 ml/s) and in the group with slightly decreased GFR (1.0 less than inulin clearance less than 1.4 ml/s), in terms of diuresis, natriuresis, kaliuresis and calciuresis. It was inefficient in the group with severe renal insufficiency (inulin clearance less than 0.3 ml/s). 5 Free water clearance showed preservation of diluting ability to a large extent. 6 In the three groups, no significant change in inulin clearance and PAH clearance occurred.
Monosodium urate (NaU), ammonium urate (NH4U) and uric acid (UA) urinary relative saturations were studied in 15 normo-uricuric calcium oxalate (CaOx) recurrent stone formers whose CaOx relative saturation was identical to age- and sex-matched controls. NaU and NH4U relative saturations were constantly below 1 and not higher in stone formers than in controls, suggesting that heterogeneous nucleation is an unlikely mechanism of CaOx stone formation in vivo. Such values of NaU relative saturation would also tend to rule out any change in the CaOx formation product or urinary inhibitory activity. However, at a given urinary flow rate, NaU relative saturation was suggestively higher in stone formers than in controls. Some disturbance in the equilibrium between NaU and urinary inhibitors might then exist even in normo-uricuric CaOx stone formers.
The plasma turnover of 125I beta 2 microglobulin (B2m) was studied in two healthy adults, two anuric patients (one of them without kidneys) and eight patients with various degrees of renal insufficiency. Results were analyzed according to a bicompartmental model. The fractional metabolic rate was positively correlated with inulin clearance, and little (less than 3.5%) extrarenal catabolism was demonstrated. The half-life of B2m in intravascular compartment varied from 107 min in normals to more than 39 hrs in the anephric patient.
One hundred and eight patients suffering from hypertension due to a unilateral parenchymatous neophropathy were studied over a period of one to eight years after treatment was starded. The aetiologies were diverse: harmonious hypoplasia, segmental hypoplasia, pyelonephritis, reflux nephropathy, hydronephrosis and tuberculosis. Thirty nine patients were treated surgically, with 50% good results. In 82 cases medical treatment was continued for at least a year with a 52% success rate. Such success was recorded in 94% of cases in which beta-blockers were used (38 cases). Surgical success was not dependent upon the period for which hypertension had been present. The best results were seen in cases of hydronephrosis and pyelonephritis and the worst in tuberculosis. Thirteen patients underwent surgery event though there was no unilateral increase in plasma renin levels. Seven were improved or cured. Ten patients underwent surgery with a renin activity 50% greater than on the healthy side, 9 being improved or cured. Treatment with beta-blockers, alone or in association with diuretics, controlled blood pressure in 90% of cases, regardless of the renin activity. Plasma renin activity in the renal veins is of good prognostic value in terms of the effectiveness of nephrectomy against hypertension. In Call cases, beta-blockers were more effective than surgery.
A retrospective study made of 114 cases of renovascular hypertension was undertaken to compare the effectiveness of different types of treatment. In this series, with a follow-up of 18 months to 9 years, a favourable result with regard to blood pressure was obtained in 45% of cases with surgery, in 63% of cases with medical treatment and in 88% of cases if treatment included beta-blockers. Medical treatment represents a valid alternative to surgery in hypertension of this type, regardless of the amount of renin secretion and whatever the criteria of ischaemia. The choice of surgery as a method of treatment thus depends above all upon the age of patient, the type of stenosis and the anatomical risk represented by the vascular malformation. Despite the very spectacular results of medical treatment, it remains essential to seek a renal cause for hypertension, since many renal conditions which require specific treatment present with hypertension alone.
Explore the source record for details and available documents.
93 patients with renal hypertension and renal vein PRA determination were studied during 1--5 years follow-up. They were separated in two groups of medical and surgical treatment. Medical treatment is able to normalize blood pressure even in cases with high asymmetric PRA. 9 of 16 patients could be cured or improved in the surgical group and 14 of 22 in the medical group. The best results were obtained if beta-blockers were included in the drug regimen: cured or improved were 7 of 33 patients in medical treatment without beta-blockers, 17 of 28 in surgical treatment, and 31 of 32 in medical treatment including beta-blockers with or without hydralazine and/or diuretics.
Explore the source record for details and available documents.
The pharmacokinetics of atenolol, a new cardioselective beta-adrenoceptor blocking agent, were determined following both acute and chronic dosing in 33 hypertensive patients with widely differing levels of renal impairment. In patients with normal renal function the atenolol half-life was calculated to be about six hours following single 100 mg oral doses. This value increased markedly in patients with renal insufficiency and the blood clearance of atenolol was found to have a significant correlation with the glomerular filtration rate. This demonstrated the importance of the kidneys in the elimination of the drug. After 8 weeks oral treatment with atenolol (100 mg twice daily) a significant decrease in blood pressure, heart rate and plasma renin activity was observed, but no correlation was established between the blood levels of atenolol and any of its pharmacodynamic effects. A positive correlation was found however between the anti-hypertensive action of atenolol and the pretreatment value of the plasma renin activity.
Forty patients suffering from idiopathic oedema were studied. The disturbance in water excretion is characterised by a delay in excretion of a water load (20 ml/kg body weight), an inability to decrease urinary osmolarity below 137 mOsm/1 standing (normal: 60 mOsm +/- 25) and an inability to increase free water clearance: 2.36 +/- 2 ml/mn/1. 73 m2 (normal value: 6.8 ml/mn/1.73 m2) in the upright position. This problem of water excretion related to orthostasis defines and characterises the syndrome, the clinical picture of which is well known. The disturbance suggest a fault in the regulation of anti-diuretic hormone whilst the aldosteronism often described would seem to be inconstant and secondary to diuretic therapy too often prescribed without supervision.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The association of thrombocytopenia, macrothrombocytopathia, nephritis and deafness is rare. Reported here is a new case of this triple association. The clinical course, the nephropathologic findings and the bilateral neurologic hearing loss were similar to those already reported, with a slowly progressive impairment of renal function accompanied by a persistent proteinuria. The platelet diameters were increased. These macroplatelets contained granules of normal structure but with an irregular distribution in the cytoplasm. In other areas the cytoplasm was rich in surface connected system. The survival of these platelets and their contraction were normal. Their aggregation and excretion in response to collagen, adenosine diphosphate and thrombin, and the values of platelet factor 3 activity were all decreased. The degranulation defect, also present, was observed in the absence of a decrease in intracellular cyclic adenosine 5'-monophosphate (AMP) suggesting a relationship between these two findings.
The effects of two new beta blockers on renal function have been studied. There were significant decreases in urine flow, urea clearance, sodium and chloride excretion rates after acute administration. Fractional excretion of sodium (FeNa) fell significantly but did not continue to fall during chronic administration. Blood pressure and plasma renin activity decreased significantly after two months' therapy. These findings suggest that beta blockers in patients with unstable cardiovascular function increase the need for concomitant diuretic therapy.