Biomedical subjects
Publications and source records attributed to G D Doyle.
Familial Mediterranean fever (fMf) is an inherited condition characterized by polyserositis and is sometimes complicated by AA renal amyloidosis leading to nephrotic syndrome and renal failure. We present a case of a man with fMf who presented with rapidly progressive renal failure caused by light chain deposition disease. This disease association has not previously been described in the medical literature.
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An open, randomised, cross-over study was performed to investigate the pharmacokinetics of enalaprilat, administered as 20 mg enalapril both as monotherapy and in combination with hydrochlorothiazide (HCTZ 12.5 mg). Three groups of 6 hypertensive patients were enrolled [untreated diastolic blood pressure (DBP) 90-115 mm Hg]; normal renal function [glomerular filtration rate (GFR) > 81 ml min-1 1.73 m-2], mild renal impairment (GFR 51-80 ml min-1 1.73 m-2), and moderate renal impairment (GFR 31-50 ml min-1 1.73 m-2). The pharmacokinetics of enalaprilat and enalaprilat plus HCTZ correlated predictably with renal impairment with increased plasma concentrations and decreased urinary elimination at lower values of GFR. The coadministration of HCTZ had no significant effect on the pharmacokinetics of enalaprilat in any group. We conclude that although the pharmacokinetics of both enalaprilat and HCTZ are related to renal function, HCTZ has no significant effect on the pharmacokinetics of enalaprilat and that dosage adjustment for both regimens should be based on renal function.
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Acetyl-L-carnitine 1.5 g and 3.0 g was administered as three divided doses on each of two occasions to 24 people with varying renal failure (creatinine clearance 127-8 ml.min-1). Plasma and urinary concentrations of total-L-carnitine, free (non-esterified) carnitine, short-chain esters and acetyl-L-carnitine were measured. The baseline (pre-study) concentrations of all four substances were related to renal function. Patients whose creatinine clearance was below about 30-40 ml.min-1 were had the highest concentrations. Renal elimination of all four substances was related to dose and to renal function. There was evidence for dose-related elimination, with greater elimination of the larger dose.
Dilevalol, 200 mg, was administered orally as seven daily doses to three groups of six participants, with differing degrees of renal impairment. Values of Cmax, Tmax, half-life or renal elimination did not significantly change with decreased renal function. Values of area under the plasma concentration-time curves and pre-dose concentrations tended to increase with renal impairment and there was a significant, if small, correlation between these and glomerular filtration rate. The practical clinical consequences of these results is that impairment is not likely to be associated with significant accumulation of dilevalol.
Amlodipine was administered as 14 single 5-mg oral daily doses to 27 male subjects with renal function ranging from normal to haemodialysis-dependent. Blood specimens were obtained for measurement of plasma amlodipine concentrations for 24 h following the first dose, for 168 h following the final dose and during daily administration of amlodipine. Amlodipine was well tolerated. Renal impairment had little effect on the pharmacokinetics of amlodipine. The elimination half-life was of the order of 50 h, similar to previously reported values and did not vary with renal function. Steady-state pre-dose concentrations were observed after the ninth dose. Accumulation of amlodipine was not significantly different from that expected on theoretical grounds and did not significantly change with renal function. These results suggest that once daily administration of amlodipine is suitable for all degrees of renal function and that dosage adjustment is not necessary in renal impairment.
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Two cases of Caroli's disease confined to the left lobe of the liver are described. One patient is a 13-yr-old who presented with acute pancreatitis. The second patient presented with obstructive jaundice at age 60. In the latter case, the diagnosis was made by percutaneous transhepatic cholangiography, in the former by postoperative T-tube cholangiography. The diseased bile ducts were not resected in either patient. Both remain well at 4 and 5.5 yr postoperatively. Monolobar involvement in Caroli's disease has been described previously in only 34 published cases, and these are reviewed in detail.
Lisinopril, a long-acting angiotensin-converting enzyme inhibitor, is excreted unchanged by the kidney. To determine how reduced renal function affects the drug's antihypertensive efficacy and safety, we studied 26 patients with hypertension associated with impaired renal function, having glomerular filtration rates (GFRs) of 60 ml/minute or less. These patients were enrolled in an open trial of 12 weeks' duration. They were given single daily doses of lisinopril, starting with 2.5 mg in patients with a GFR of less than 30 ml/minute, and 5 mg in the other patients. The dose was titrated to a maximum of 40 mg daily according to the blood pressure response. A diuretic was then added if required. Mean sitting and standing blood pressures at four, eight, and 12 weeks of treatment were significantly reduced compared with pretreatment values. The median dose of lisinopril was 10 mg daily (range, 2.5 to 40 mg), and only four patients required the addition of a diuretic. The mean GFR was unchanged during the study (36 +/- 16.4 ml/minute at baseline, 39 +/- 20.8 ml/minute after 12 weeks of treatment). Twenty-five patients completed the study. The one patient withdrew because of nausea and vomiting due to reflux esophagitis, which was probably not drug-related. Another patient had transient angioneurotic edema and continued to receive lisinopril. No clinically significant hematologic or biochemical abnormalities were observed. Sixteen patients continued to receive lisinopril for one year. Blood pressure control and GFR were well maintained throughout. Thus, in a group of patients who are often difficult to treat, lisinopril provided highly effective blood pressure control and was generally well tolerated.
The antihypertensive efficacy and safety of lisinopril were assessed in 60 older patients with a mean age of 75 years (range, 65 to 85 years) in a 12-week open study. Mean ( +/- SEM) blood pressure while sitting was reduced from 190/106 +/- 3.3/1.8 mm Hg at entry to 162/89 +/- 3.2/1.6 mm Hg after 12 weeks of treatment (p less than 0.001). There was no significant alteration in heart rate, and postural hypotension did not occur. Mean glomerular filtration rate at entry was 61.6 +/- 3.4 ml/minute and was unchanged after 12 weeks of therapy at 62.2 +/- 3.0 ml/minute. Fourteen patients continued to receive lisinopril for a period of one year. Blood pressure remained controlled throughout and heart rate remained unchanged. There was a significant reduction in mean arterial pressure from 128.8 +/- 1.9 mm Hg to 105.1 +/- 1.5 mm Hg (p less than 0.001). Biochemical parameters remained unaltered. There was a significant increase in renal blood flow (p less than 0.025) and a corresponding reduction in renovascular resistance (p less than 0.001) following long-term therapy with lisinopril. Thus, lisinopril was generally well-tolerated and highly effective in lowering blood pressure in older hypertensive patients, whereas at the same time renal function was not adversely changed.
The pharmacokinetics of amlodipine was studied in 27 subjects with renal function ranging from normal to dialysis-dependent. Amlodipine (as a single 5-mg capsule) was administered once daily for 14 days and its plasma concentrations were measured by gas chromatography during and after treatment. Renal impairment had little or no effect on the pharmacokinetics of amlodipine. The elimination half-life was of the order of 50 h, similar to previously observed values, and did not vary with differences in renal function. Steady-state predose concentrations were observed after the ninth dose. Accumulation of amlodipine to steady-state levels was not significantly different from that expected on theoretical grounds and did not significantly change with renal function. These results suggest that once-daily administration of amlodipine is suitable for all degrees of renal function and that dosage adjustment is not necessary in renal impairment.
1. Lisinopril and enalapril were administered as 2.5 mg single doses and as eight single daily 2.5 mg doses to separate groups of six patients with chronic renal failure. Patients were receiving regular haemodialysis. 2. In the absence of haemodialysis, the decline in plasma concentrations of lisinopril and enalaprilat was extremely slow and plasma concentrations were generally high. 3. Haemodialysis had large effects on plasma concentrations of lisinopril and enalaprilat. A 4 h period reduced plasma concentrations of both drugs by around one-half and often by significantly more than this. Even 1 or 2 h of haemodialysis had significant effects. 4. Haemodialysis plasma clearance was similar for both drugs with mean values of the order of 40 ml min-1. Clearance did not markedly differ when measured after 1, 2 or 4 h of haemodialysis or after single or multiple doses of lisinopril or enalapril. 5. The design of dosage regimens of both lisinopril and enalapril for patients with severe renal impairment or chronic renal failure should take into consideration the use and effects of haemodialysis.
The antihypertensive efficacy and safety of lisinopril, a long-acting angiotensin-converting enzyme inhibitor, were assessed in 23 patients with hypertension associated with impaired renal function (glomerular filtration rate 60 ml/min or less) in an open study of 12 weeks' duration. Lisinopril was given orally in single daily doses. The starting dose was 2.5 mg in patients with glomerular filtration rate (GFR) of less than 30 ml/min and 5 mg in all other patients. This was titrated to a maximum of 40 mg daily according to blood pressure response. A diuretic was then added if blood pressure was not controlled. Mean sitting and standing blood pressures were significantly reduced by lisinopril treatment. The median dose of lisinopril taken was 10 mg daily (range 2.5-40 mg), and only three patients required the addition of a diuretic. The mean glomerular filtration rate was unchanged during the study (38 +/- 16.4 ml/min at baseline, 41 +/- 21.0 ml/min after 12 weeks of treatment). Twenty-two patients completed the study. One patient was withdrawn because of nausea and vomiting due to reflux oesophagitis which was probably not drug related. Another patient had transient mild angioneurotic oedema and continued on lisinopril. No clinically significant haematological or biochemical changes were observed. In conclusion, lisinopril provided effective blood pressure control and was well tolerated in this group of hypertensives who are typically difficult to treat.
Lisinopril is a new, long-acting, nonsulfhydryl angiotension-converting enzyme (ACE) inhibitor that is excreted unchanged by the kidney. The antihypertensive efficacy and safety profiles of lisinopril were assessed in 24 patients (15 men, 9 women; mean age 52.3 years; range 21-75 years) with hypertension associated with impaired renal function (glomerular filtration rate GFR 60 ml/min or less), in an open study of 12 weeks' duration. Previous antihypertensive drugs were discontinued at entry into the study. Lisinopril was given orally once daily; the starting dose was 2.5 mg in patients with a GFR of less than 30 ml/min, and 5 mg in all other patients. The dosage of lisinopril was titrated upward to 40 mg daily according to BP response. A diuretic could then be added if hypertension was inadequately controlled. Twenty-three patients completed the study. Mean sitting BP was reduced from 177 +/- 21.2/106 +/- 9.1 mm Hg (mean +/- SD) at entry to the study to 145 +/- 21.4/88 +/- 8.3 mm Hg after 12 weeks of treatment (p less than 0.001). The median dose of lisinopril used was 10 mg (range 2.5-40 mg) and only 4 patients had a diuretic added to the lisinopril. Overall GFR was unchanged during the study: mean baseline value was 37 +/- 16.4 ml/min (range 10-60 ml/min) at the beginning of the study and 40 +/- 21.0 ml/min at the end. As in a previous pharmacokinetic study in similar patients, a tendency toward drug accumulation was noted only in those patients with the most severe renal impairment.(ABSTRACT TRUNCATED AT 250 WORDS)
Sarcoidosis and IgA nephropathy diagnosed simultaneously in a 23-year-old male patient is described. This association is most unusual. The possible inter-relationship between the two conditions is discussed.
In order to correlate symptoms, osteoid volume, and aluminum deposition in bone, 46 methacrylate-embedded biopsy specimens from 26 hemodialysis patients were examined. Osteoid volume was measured using computer-assisted morphometric analysis, and aluminum was detected using the Aluminon stain. Positive staining for aluminum was present in biopsies from 21 patients. Osteoid volume did not correlate with duration of dialysis therapy or ingestion of aluminum hydroxide but displayed a logarithmic relationship with dialysate aluminum exposure. Patients with bone pain at the time of biopsy had a greater degree of hyperosteoidosis than asymptomatic subjects. Osteoid volume in patients with fractures and positive aluminum staining decreased on withdrawal from aluminum-rich dialysate. The Aluminon staining technic is a convenient method of confirming aluminum overload.