Biomedical subjects

J D Wallin

Publications and source records attributed to J D Wallin.

At least 19 recordsLinked to original sources

PubMed1999

Antihypertensive effect of the combination of fosinopril and HCTZ is resistant to interference by nonsteroidal antiinflammatory drugs.

Nonsteroidal antiinflammatory drugs (NSAID) are frequently reported to interfere with the blood pressure lowering actions of various antihypertensive medications. We studied 17 women with arthritis and hypertension who were receiving fosinopril and HCTZ, and administered sequentially in random order ibuprofen, sulindac, and nabumetone for 1 month each, with an intervening 2-week washout period between each treatment period. During the washout period, subjects received acetaminophen. Blood pressure at the end of 2 weeks of acetaminophen was compared with blood pressure after 1 month of treatment with each of the NSAID. Mean blood pressure was unchanged before and after all NSAID: 108 +/- 7 v 107 +/- 9 for nabumetone, 108 +/-9 v 108 +/- 9 for sulindac, and 108 +/- 8 v 107 +/- 9 for ibuprofen. The 24-h urinary sodium excretion was not significantly different. We conclude that the three NSAID did not neutralize the antihypertensive effect of the combination of fosinopril and HCTZ, and hence the blood pressure lowering action of the combination may not be prostaglandin dependent.

Acetaminophen↗

PubMed1998

End-stage renal disease in specific ethnic and racial groups: risk factors and benefits of antihypertensive therapy.

During the past few years, it has become apparent that there are factors that place a person at greater risk for the development and progression of renal failure. This has been documented since the early 1980s by the United States Renal Data System that has collected data confirming that end-stage renal disease occurs at a greater rate in certain subpopulations of Americans. It is evident from an examination of the data that African Americans and American Indians have an incidence of end-stage renal disease that is not proportional to their percentage of the total population. In fact, African Americans and American Indians are reported to have at least a 4-fold greater incidence of end-stage renal disease than white Americans. There have been 5 factors identified: hypertension, glucose intolerance, insulin resistance, salt sensitivity, and hyperlipidemia, which may play a greater role in these subpopulations. In addition, as with other populations, lifestyle issues may serve to alter these primary risk factors or may act as direct modulators of renal disease progression. There is also a possibility that interactions between risk factors frequently occur that may modify the development or progression of the disease. This article reviews these risk factors and emphasizes the interaction between hypertension and the other factors. In addition, the effects of antihypertensive agents on risk factors and on renal outcome are emphasized. Where possible, issues specific to African Americans and American Indians are underscored; however, one must accept that the database on these populations is only now developing. This review should help the clinician make appropriate choices when prescribing antihypertensive therapy for patients who may be at risk of developing progressive renal failure.

Black or African American↗

PubMed1997

Comparative effects of nabumetone, sulindac, and ibuprofen on renal function.

OBJECTIVE: Nonsteroidal antiinflammatory drugs (NSAID) have been associated with hemodynamically mediated acute renal failure. There appear to be differences among NSAID in producing this effect. We compare renal effects of ibuprofen, sulindac, and nabumetone. METHODS: Seventeen women over age 56 receiving hydrochlorothiazide and fosinopril for hypertension who had osteoarthritis requiring NSAID received 3 different NSAID to evaluate potential varying renal effects. In an investigator blinded randomized study, patients received nabumetone, sulindac, or ibuprofen for 1 month with intervening 2 week control periods. After each period renal function was assessed by inulin and para-aminohippurate clearances and urinary prostaglandins were measured. RESULTS: No overall statistical differences among the NSAID were observed. However, there were clinically meaningful differences during ibuprofen therapy: 4 patients developed a clinically significant decrease in renal function; during sulindac therapy one of these also developed a clinically significant decrease in renal function. During nabumetone there were 0 episodes of clinically significant decrease in renal function. Using Gomez equations, glomerular hydrostatic pressure and afferent and efferent arteriolar resistances were estimated. None changed overall during any intervention. However, the 4 patients who developed decreased renal function while taking ibuprofen were analyzed separately. Glomerular hydrostatic pressure decreased 15%; afferent arteriolar resistance increased 85%. These changes were associated with marked decreases in vasodilatory prostaglandins compared to patients receiving ibuprofen who did not develop decreases in renal function. CONCLUSION: There are differences in effect on renal function among NSAID. These can be correlated with specific alterations in suppression of the cyclooxygenase system cascade and related to changes in the hemodynamic control of glomerular filtration.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1996

Calcium antagonists and the kidney.

Calcium antagonists have evolved as an important class of cardiovascular therapeutic agents. Usefulness in treating hypertension, angina pectoris, and cardiac arrhythmias has been established. Investigations show that calcium antagonists have a role in altering renal functions. They are natriuretic and may benefit salt-sensitive hypertensives. They have been shown to block vasoconstriction of the afferent arteriole in the presence of constrictors such as endothelin, thromboxane, norepinephrine, and angiotensin II. These vasoconstrictors may be mediators of nephrotoxins such as radiocontrast agents, and cyclosporine A. Actions of calcium antagonists which are being investigated for potential benefit in ameliorating chronic renal disease include: preventing glomerular hypertrophy, blocking angiotensin II-mediated macromolecule entry into mesangial cells and cytokine release, free-radical scavenger activity, and decreasing calcium deposition within the kidney. Slowing the progression of renal disease with the calcium antagonists has been demonstrated in both short- and long-term trials. Further studies are currently underway.

Animals↗

PubMed1993

Renal failure and hyperkalemia associated with ketorolac tromethamine.

Three patients who were treated with ketorolac tromethamine (Toradol), an injectable nonsteroidal anti-inflammatory drug for pain management, developed acute renal failure or hyperkalemia or both. These complications were reversible in two cases after discontinuing the drug. Clinical conditions preexisted in each patient that rendered them susceptible to the renal complications of nonsteroidal anti-inflammatory use. It is well known that caution should be observed while using nonsteroidal anti-inflammatory drugs in patients whose renal function may be preserved through prostaglandin-mediated vasodilatory effects. The same cautions apply to ketorolac. Since its major marketed use is as an analgesic and its potent effect on prostaglandin synthesis may not be well recognized, those cautions must be emphasized.

Acute Kidney Injury↗

PubMed1992

Transdermal clonidine as an adjunct to enalapril: an evaluation of efficacy and patient compliance.

This four-center, 20-week, open-label study evaluated transdermal clonidine as an adjunct to enalapril 10 mg daily and demonstrated patterns of compliance. Seventy-four mildly to moderately hypertensive patients (mean seated blood pressure, 150/101 mm Hg) received enalapril 10 mg once daily as initial monotherapy. In 66 patients, the seated diastolic blood pressure remained greater than or equal to 90 mm Hg at the trough blood levels of enalapril. Transdermal clonidine (3.5 cm2, 7.0 cm2, or 10.5 cm2, equivalent to 0.1 mg, 0.2 mg, and 0.3 mg clonidine/day, respectively) then was added as needed to achieve blood pressure control. Forty-eight patients achieved diastolic blood pressures less than 90 mm Hg on concomitant therapy; 44 patients completed 8 weeks of maintenance dosing with a mean blood pressure of 134/85 mm Hg. Oral compliance, as measured by an electronic device that was actuated each time the medication vial was opened, varied from 48 to 140%. Compliance with the transdermal clonidine regimen was excellent; the patch was worn as directed during 96% of the patient-weeks of therapy. The authors conclude that blood pressure can be controlled by a combination of transdermal clonidine and enalapril in patients that do not adequately respond to enalapril monotherapy. Patients poorly complying with oral regimens may be candidates for a trial of transdermal clonidine monotherapy.

Administration, Cutaneous↗

PubMed1991

Therapeutic adherence in the elderly: transdermal clonidine compared to oral verapamil for hypertension.

This double-blind, double-dummy, randomized clinical trial, conducted in elderly patients with mild hypertension, compared adherence to treatment, efficacy, side effects, and quality of life during treatment with transdermal clonidine versus oral sustained-release verapamil (verapamil-SR). Blood pressure declined significantly--from 148/95 mm Hg at baseline to 139/84 after titration and 135/86 after maintenance--with transdermal clonidine (n = 29), and from 156/96 to 144/85 and 148/88, respectively, with verapamil-SR (n = 29). Adverse event rates and quality-of-life questionnaire responses were similar in the two treatment groups. Transdermal clonidine was worn as directed during more than 96% of patient-weeks of treatment. Compliance with the oral verapamil regimen was less consistent: Verapamil-SR was taken as directed during approximately 50% of patient-weeks of therapy, and individual compliance, assessed by tablet counts, varied from 50-120%. In all, 86% of subjects were satisfied or highly satisfied with the convenience of transdermal therapy; 87% reported that side effects were slightly or not bothersome; 65% indicated that transdermal patches were more convenient than oral therapy; and almost 60% preferred transdermal to oral therapy. In this study transdermal clonidine and oral verapamil were equally safe and effective. A substantial majority of patients preferred transdermal to oral therapy, and adherence to treatment was greater with transdermal therapy.

Administration, Cutaneous↗

PubMed1990

Intravenous nicardipine hydrochloride: treatment of patients with severe hypertension.

Nicardipine hydrochloride, a dihydropyridine calcium entry-blocking drug, was administered to 66 patients with severe hypertension during three protocols designed to examine the efficacy and safety of this investigation drug. It was shown that nicardipine was uniformly effective in lowering blood pressure to a therapeutic goal of 95 mm Hg. Time to achieve therapeutic effect was dose dependent, and steady-state blood levels were achieved after 8 to 12 hours. Reductions in both systolic and diastolic blood pressure but not changes in heart rate were correlated with plasma concentrations of nicardipine. In dose-ranging studies, the minimal effective dose of nicardipine appeared to be 2 mg/hr; 1 mg/hr was an ineffective dose, and little additional effect was seen above 4 mg/hr. Side effects were modest and consisted of those associated with vasodilation--headache, flushing, and feelings of warmth. In the initial group of patients studied, local thrombophlebitis occurred in a substantial number of patients. This was seen only after 14 hours of infusion. In subsequent studies, the infusion site was changed after 12 hours, and no further cases of thrombophlebitis were seen. Nicardipine appears to be therapeutic agent for parenteral use that shows promise in the treatment of severe hypertension.

Blood Pressure↗

PubMed1990

Ureteral obstruction due to blood clot following percutaneous renal biopsy: resolution with intraureteral streptokinase.

The nonsurgical approach to unilateral ureteral obstruction due to impaction of a blood clot is described. A patient with the nephrotic syndrome secondary to minimal change disease had gross hematuria and acute renal failure following percutaneous renal biopsy. After he responded to prednisone therapy, clot obstruction developed at the site of the percutaneous biopsied kidney, which was treated with intracaliceal infusion of streptokinase via a ureteral catheter. Complete resolution of the clot and the urinary tract obstruction was accomplished within 3 days. This approach appears to be the treatment of choice in upper urinary tract obstruction secondary to blood clots when simple ureteral catheter drainage is ineffective.

Adult↗

PubMed1990

The effects of mercuric chloride on calmodulin-mediated Ca2+ transport in rat brain.

We have shown previously that mercuric chloride (HgCl2) inhibits in vitro vasopressin release from the isolated rat neurohypophysis with maximum inhibition occurring with 0.5 mM HgCl2. Associated with the inhibition of hormone release is an increase in 45Ca+2 uptake, an increase in cytosolic 45Ca+2, and a reduction of 45Ca+2 accumulation by mitochondria in the intact gland. In the present series of studies, the effect of HgCl2 on calmodulin (CM) function in neural tissue preparations is reported. Mercuric chloride (0.5 mM) reduced 45Ca+2 binding to CM purified from bovine neurohypophyses by 20% and inhibited endogenous CM-stimulated Ca,Mg-ATPase activity from rat brain mitochondria in a dose-dependent fashion. Ca,Mg-ATPase activity was inhibited by 50 and 80% with 0.5 and 5.0 mM HgCl2, respectively. CM-stimulation of Ca,Mg-ATPase activity was inhibited by calmidazolium (CMZ) with maximal inhibition seen with 0.1 mM CMZ. Reversibility of the HgCl2 interaction with CM was demonstrated using CM-stimulated phosphodiesterase (PDEase) activity from rat brain. HgCl2 inhibited both basal and CM-stimulated PDEase activity in a dose-dependent manner with maximum inhibition occurring with 1.0 mM HgCl2. Preexposure of CM to an inhibitory concentration (1.0 mM) of HgCl2 resulted in no loss of stimulatory PDEase enzyme activity. From these results, we conclude that HgCl2 reversibly interferes with 45Ca+2 binding to CM and also inhibits CM-regulated Ca+2 pumping enzyme systems in the neurohypophysis. The inhibition of vasopressin release from the intact gland in the presence of HgCl2 thus, may be associated with a disruption of calcium in the neurohypophysis.

Animals↗

PubMed1990

Intravenous nicardipine: an effective new agent for the treatment of severe hypertension.

Fifty-six patients with severe hypertension were treated with intravenous nicardipine for infusion periods of eight to twenty-four hours. Each patient achieved satisfactory blood pressure control during the infusion period with a mean controlling dose of 7.85 mg/hr. The dose of nicardipine needed for sustained blood pressure control correlated with untreated diastolic blood pressure but not with untreated systolic blood pressure. These results demonstrate the potential usefulness of intravenous nicardipine for the treatment of severe hypertension requiring rapid lowering, and they suggest also that the severity of pretreatment diastolic hypertension might be a useful indicator of the dose required for blood pressure control.

Acute Disease↗

PubMed1990

Nicardipine in severe hypertension: oral therapy following intravenous treatment.

Nicardipine is an investigational dihydropyridine calcium-channel blocker. In the present study, 21 patients with severe hypertension were treated with oral nicardipine, alone or in combination with beta-blockers and diuretics for 4-5 weeks, following initial control of their blood pressure with intravenous nicardipine. Each of the 21 patients had a satisfactory response to intravenous nicardipine which was administered as an infusion following initial blood pressure lowering. At 1 h prior to discontinuation of the intravenous treatment, oral nicardipine therapy was begun as a 40 mg dose. Oral nicardipine, 40 mg t.i.d., was continued for the remainder of hospitalization and for a 4-5-week outpatient follow-up period. The dose of oral nicardipine was downtitrated and additional antihypertensive drugs, beta-adrenergic blocking agents and/or diuretics, were added to maintain blood pressure in an acceptable range. Compared to baseline, mean supine systolic blood pressure was lowered significantly (p less than 0.001) by 57 mmHg at the end of intravenous maintenance and by 50 mmHg at the end of oral treatment. Likewise, significant (p less than 0.001) decreases in diastolic blood pressure of 43 and 32 mmHg, respectively, were observed for the same time periods. At the end of oral treatment, 6 patients remained on nicardipine monotherapy, 8 patients were on two-drug therapy and 7 patients required three-drug therapy. Side-effects were mild except for a moderate headache reported in one patient during intravenous treatment. From these observations we conclude that oral nicardipine is a useful new agent for initial, single treatment of chronic severe hypertension, although a significant number of patients eventually need additional antihypertensive therapy.

Administration, Oral↗

PubMed1989

Intravenous nicardipine in severe systemic hypertension.

Sixty-six patients with severe hypertension were treated with intravenous nicardipine in 3 separate protocols. Each protocol had a common end point: Diastolic blood pressure would either reduce 25 mm Hg or measure below 95 mm Hg. Each of the 66 patients studied attained the desired clinical response end point. Intravenous nicardipine produced a gradual reduction in blood pressure, was effective in maintaining blood pressure control during constant infusion and had few undesirable effects. These observations suggest that intravenous nicardipine maybe a useful addition to a limited number of therapeutic agents currently available to the physician for treatment of hypertensive urgencies.

Adult↗

PubMed1989

Dilevalol compared with propranolol and placebo for systemic hypertension.

Dilevalol is a new antihypertensive agent that is both a vasodilator, through its beta 2-agonist action, and a nonselective beta antagonist. Two multicenter, double-blind studies were performed: study 1 compared dilevalol administered once-daily with either dilevalol or propranolol every 12 hours; study 2 compared dilevalol administered once daily with placebo. Both studies had a placebo run-in period to establish that the baseline supine diastolic blood pressures were consistent in the mild to moderate severity range (95 to 115 mm Hg) at 2 consecutive visits for study 1 and in the mild severity range (95 to 105 mm Hg) in study 2. Patients then were randomized to the double-blind titration phase, during which doses were titrated over a 9-week period to achieve a supine diastolic blood pressure of less than 90 mm Hg and a decrease from baseline of greater than or equal to 10 mm Hg. Patients were then maintained on a fixed dose for 2 months (study 1) or for 1 month (study 2). Dilevalol given once daily was as effective in reducing supine diastolic blood pressure as dilevalol every 12 hours and propranolol every 12 hours (study 1) and was superior to placebo (p less than 0.001) (study 2). In both studies, dilevalol given once daily was effective and well tolerated. The side-effect profile of dilevalol was similar to that of placebo and different from that of propranolol. Treatment with dilevalol resulted in significantly less fatigue (p less than 0.05), bradycardia (less than 50 beats/minute) and mental depression than with propranolol, but significantly (p less than 0.05) more diarrhea/loose stools.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Effects of dilevalol on renal function.

Renal function was measured in a total of 35 volunteers and patients who were given dilevalol, the R,R optical isomer of labetalol. Young normotensive volunteers (n = 6) and elderly normotensive volunteers (n = 12) received single 400- and 200-mg doses of dilevalol, respectively. Renal function was determined in these subjects on the same day before and after dosing. In addition, patients with mild to moderate essential hypertension (n = 11) and hypertensive patients with renal insufficiency (n = 6) were treated with placebo to establish baseline blood pressure and then were given dilevalol, 400 to 1,600 mg/day, for 2 to 6 weeks until blood pressure was controlled. Renal function was determined at the end of the baseline period and again at the end of dilevalol treatment. A subgroup of elderly hypertensives from the 2 protocols used to study hypertensive patients was treated as a separate study group. The only effect on parameters of renal function seen in any of the study groups was a statistically significant 15% decrease in glomerular filtration rate after single-dose treatment in the elderly normotensive group. Effective renal plasma flow, filtration fraction, renal blood flow and renal vascular resistance were unchanged before and after treatment in all groups. Mean arterial pressure was reduced significantly in all groups except in the elderly normotensive volunteers. Dilevalol appears to be a well-tolerated, effective therapeutic agent that is neutral regarding its effect on renal function and potentially useful in a variety of patient populations.

Adult↗

PubMed1989

Dilevalol: a selective beta-2 adrenergic agonist vasodilator with beta adrenergic blocking activity.

Dilevalol is the R-R' optical isomer of labetalol and differs pharmacologically from the racemic mixture in the following ways: it is seven-fold more potent as a selective beta-2 agonist; it is four times more potent as a nonselective beta antagonist; it has no clinically significant alpha antagonist property. Dilevalol is a vasodilator and reduces blood pressure by reducing systemic vascular resistance. It has a half-life of 15-18 hours, and is demonstrated to be effective as an antihypertensive agent for 24-30 hours. Hemodynamic studies in humans show that following administration of dilevalol either orally or intravenously, blood pressure falls as a consequence of a decrease in systemic vascular resistance. Cardiac index is unchanged and heart rate decreases slightly. Dilevalol is shown to cause regression of left ventricular hypertrophy in younger individuals, to improve left ventricular performance and to have no effect on parameters of renal function. Prospective double-blinded clinical trials in comparison with placebo, propranolol, metoprolol and atenolol were conducted and demonstrate dilevalol to be an effective antihypertensive agent with a favorable side effect profile with a particularly low incidence of central nervous system side effects.

Animals↗

PubMed1989

Monoexponential analysis of plasma disappearance of 99mTc-DTPA and 131I-iodohippurate: a reliable method for measuring changes of renal function.

Glomerular filtration rate and effective renal plasma flow were measured in 170 subjects using monoexponential analysis of plasma disappearance curves for 99mTc-DTPA and 131I-iodohippurate after single injection. In the current study population, glomerular filtration rate and effective renal plasma flow decreased with increasing age, were less in females than in males, and were less in hypertensives than in normotensives. Differences in glomerular filtration rate according to age and sex in the current study were similar to those reported using traditional creatinine clearance methodology. Monoexponential treatment of plasma isotope disappearance gave reproducible values for both glomerular filtration rate and effective renal plasma flow when measured either during the day or on a daily basis. Intraindividual coefficient of variation was less than 10% for both 99mTc-DTPA and 131I-iodohippurate clearances derived from monoexponential analysis. These results demonstrate that monoexponential analysis of plasma disappearance curves for 99mTc-DTPA and 131I-iodohippurate after a single injection is a useful method for evaluating changes in renal hemodynamics either during chronic drug therapy or acutely after single dose administration.

Adult↗

PubMed1989

The renal function and blood pressure effects of dilevalol in the normotensive and hypertensive elderly.

Dilevalol, the R-R optical isomer of labetalol, is a nonselective beta adrenergic blocking drug with selective beta-2 agonist properties. In a double-blind, crossover study the renal function effects of dilevalol were compared to placebo in 12 normotensive elderly volunteers before and after single dose administration. In addition, chronic treatment (greater than 4 weeks) effects of dilevalol were determined in eight elderly patients with mild to moderate essential hypertension. Renal function was determined by plasma disappearance curves from single injections of 99mTc-DTPA and 131I-orthohippurate. In both study populations renal function tests commenced two hours after dosing at expected peak plasma levels of dilevalol. Normotensive volunteers had an acute decrease in glomerular filtration rate of 10.3 ml/min, which was significant (P less than 0.05), while hypertensive patients had no change in glomerular filtration rate. There were no significant changes in other parameters of renal function measured. In the hypertensive elderly dilevalol treatment resulted in significant reductions, 18 and 19 mmHg respectively, of systolic (P less than 0.01) and diastolic (P less than 0.001) blood pressure. Heart rate was reduced by 5 beats per minute, and the change was not statistically significant. Dilevalol appears to be an excellent agent for treatment of hypertension in the elderly hypertensive patient, and does not change renal function when administered chronically to the hypertensive patient. Small but significant decrements in glomerular filtration rate occur with acute administration to normotensive volunteers.

Aged↗