Arrhythmogenic potential of diuretic induced hypokalaemia in patients with mild hypertension and ischaemic heart disease

In view of evidence suggesting an association of mild hypokalaemia with cardiac arrhythmia, the arrhythmogenic potentials of potassium losing and potassium sparing diuretic treatments were compared in a controlled prospective crossover study of 10 patients with mild hypertension and ischaemic heart disease. Mean (SEM) plasma potassium was 4.3(0.06) mmol/l and 3.3(0.07) mmol/l after potassium sparing and potassium losing treatments respectively. Blood pressure and volume depletion as assessed by weight change, plasma renin activity, and noradrenaline concentrations did not differ significantly in the two treatment periods. The potassium losing treatment phase was associated with an increased frequency of ventricular extrasystoles, a higher Lown grading during ambulatory electrocardiographic monitoring, prolonged duration and decreased phase 0 velocity of the monophasic action potential, a prolonged ventricular effective refractory period, and increased myocardial electrical instability as assessed by programmed ventricular stimulation. It is concluded that minor changes in plasma potassium concentration are associated with increased ventricular electrical instability in patients with ischaemic heart disease. Mild hypokalaemia in such patients may predispose to life threatening arrhythmias and should be avoided.

Atenolol and chlorthalidone in combination in the management of older hypertensive patients: a randomized clinical trial

In a double-blind, crossover study in 100 elderly hypertensive patients, the hypotensive effect of a fixed combination of atenolol (50 mg) with chlorthalidone (12.5 mg) was compared with that of each of its component drugs given alone. Patients were allocated at random into two groups: one group received treatment for 4 weeks with either the combination or atenolol alone before being crossed over to the alternative medication for a further 4 weeks; the other group received either the combination or chlorthalidone alone and followed the same treatment pattern. Dosage was a single tablet per day given in the morning. Blood pressure and pulse rate were measured approximately 24 hours after dosing at the end of each treatment period. The results showed that significantly lower blood pressures were achieved, both in the standing and lying positions, with the combination than with either atenolol or chlorthalidone used alone. Combination treatment was well tolerated, few side-effects being reported and there was no significant disturbance of plasma electrolytes.

Different effects of metoprolol and chlorthalidone on serum lipoprotein levels in mild hypertension. Possible implications for coronary heart disease risk status

The effects of chlorthalidone and metoprolol on fasting plasma lipids and lipoprotein levels were compared in two similar nonrandomized groups of patients with mild hypertension. Chlorthalidone therapy was associated with an increase in serum cholesterol of 8.1% (17 mg/dl), mainly reflecting an increase in low-density lipoprotein (LDL)-cholesterol. High-density lipoproteins (HDL)-cholesterol decreased, but the difference between pre- and posttreatment levels did not reach statistical significance. Serum triglyceride (TG) concentration increased by 16% (20 mg/dl). Metoprolol therapy was not associated with changes in total, very low-density lipoprotein (VLDL)-, LDL- and HDL-cholesterol levels. Serum TG concentration increased by 22% (28 mg/dl), mainly due to an increase in VLDL-TG. Application of the Israel Ischemic Heart Disease Study data to these findings could predict only a very slight decrease in the 5-year estimated probability of myocardial infarction in the chlorthalidone-treated group. Metoprolol therapy has, theoretically, a more favorable influence on coronary heart disease risk status. These data suggest that the different forms of therapy for mild hypertension have a different effect on the theoretical coronary heart disease risk status, a fact that should be taken into consideration in the choice of medication.

Comparison of the effectiveness of a beta blocker (atenolol) and a diuretic (chlorthalidone) in black hypertensive patients

A double-blind crossover trial of atenolol and chlorthalidone was done in black Jamaican hypertensive patients. After an initial four weeks of single drug therapy, the beta blocker and thiazide diuretic were used in combination. Chlorthalidone at a daily dose of 25 mg produced a significant (P less than .05) fall in the mean systolic and diastolic pressures (19.4 mm Hg and 12.2 mm Hg, respectively); atenolol produced a significant fall in the diastolic blood pressure (6.5 mm Hg); and combination therapy produced a reduction in systolic and diastolic blood pressures (27.8 mm Hg and 17.8 mm Hg, respectively). The study showed that combination therapy using a low dose of thiazide diuretic and a beta blocker was synergetic, but that a thiazide was more effective than a beta blocker in lowering the blood pressure in black hypertensive patients.

[Clonidine-diuretic combination in patients with essential hypertension. Modification of sympathetic activity and blood pressure as well as the reaction following sudden withdrawal]

In ten patients with essential hypertension, 6 weeks of treatment with a clonidine/diuretic combination (1 retard capsule/day, 75 micrograms or 150 micrograms clonidine, and 15 mg chlortalidon) was suddenly discontinued. The blood pressure, heart rate and sympathetic tone were monitored via the noradrenaline level (NA) in the blood. The six-week treatment with an average of 97.5 micrograms clonidine and 15 mg chlortalidon/day, reduced the NA blood level from 0.48 to 0.37 ng/ml, the blood pressure from 167/102 to 142/86 mmHg, and the heart rate from 73 to 69 bpm. On the second day after termination of therapy, the NA level had increased, on average, 35% above the initial value in 4 out of the 10 patients. In the remaining six patients, the NA level was increased only slightly, and remained markedly below the pre-treatment levels. The blood pressure, however, remained below its initial levels throughout the whole of the two-week observation period. During the phase of increased sympathetic activity, the patients experienced no symptoms. The results show that even after discontinuation of a very low dose of clonidine, some patients can be expected to show a mild increase in sympathetic tone which however would seem to have no clinical significance.

Comparison of three different methods of monitoring unwanted effects during antihypertensive therapy

In a double-blind, randomized, crossover, multicenter study performed in 227 hypertensive outpatients, two antihypertensive drugs, oxprenolol and chlorthalidone, were investigated to determine unwanted effects. Three main methodologic procedures were applied: the conventional evaluation of unwanted effects by the physician and involving the whole patient population, the checklist, and the free questionnaire. The latter two were assigned by randomization to the patients themselves. The study showed that unwanted effects seem to be frequently overreported when a checklist is used, whereas the free questionnaire gives more information about the symptoms of the disease than about the tolerance of the drug. The conventional method, when physicians are well-informed and sensitized to the problem, seems to provide more reliable information about unwanted effects of a drug.

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. I

Chlorthalidone 25 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 25 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reactions.

Chlorthalidone-triamterene: a potassium-sparing diuretic combination for the treatment of oedema

The efficacy of a once-daily combination of chlorthalidone 50 mg plus triamterene 50 mg or chlorthalidone 100 mg plus triamterene 100 mg was compared to that of chlorthalidone 50 mg or 100 mg. This double-blind study was carried out in eighty-eight patients over a treatment period of 12 weeks. All patients entered the active medication period of 12 weeks after a placebo run-in period of 3 to 7 days, during which pretibial or malleolar pitting oedema averaging 2 to 4 mm developed. All patients started at the lower doses, i.e. forty-one started on chlorthalidone 50 mg plus triamterene 50 mg and forty-seven started on chlorthalidone 50 mg. The protocol provided for doubling the dose (but not for reducing it thereafter) at any time during the 12-week period when control of oedema was deemed inadequate. Eight of the combination therapy patients and sixteen of those on chlorthalidone required the higher doses. By Week 12, 96% of the chlorthalidone plus triamterene patients and 100% of the chlorthalidone patients had shown a reduction of at least 2 mm in depth of pits, and 92% and 72%, respectively, had complete disappearance of oedema. The decreases in pitting oedema were paralleled by mean weight losses of 2.4 kg and 3.1 kg, respectively, for the combination treatment group and the chlorthalidone group. Average serum potassium levels throughout the 12-week treatment period were 3.70 mEq/L for the patients taking the combination compared to 3.41 mEq/L of those taking chlorthalidone.(ABSTRACT TRUNCATED AT 250 WORDS)

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. II

Chlorthalidone 50 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 50 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reaction.

Propranolol versus chlorthalidone--a prospective therapeutic trial in children with chronic hypertension

A prospective study of propranolol versus chlorthalidone has been performed in eleven patients with renal hypertension and one with essential hypertension. The patients were treated for 4 to 6 weeks consecutively. Both drugs proved to be effective in lowering elevated systolic and diastolic blood pressure. The mean blood pressure decreased by 22.3 mm Hg in propranolol-treated patients and by 15 mm Hg in chlorthalidone-treated patients. One patient developed an asthmatic attack provoked by propranolol. Four of twelve patients receiving chlorthalidone developed hypokalemia and required potassium supply. Both drugs can be recommended as drugs of first choice in children with hypertension.

Diuretic-induced hypokalemia in uncomplicated systemic hypertension: effect of plasma potassium correction on cardiac arrhythmias

Sixteen patients with diuretic-induced hypokalemia underwent 24-hour ambulatory electrocardiographic monitoring during and after correction of hypokalemia. Plasma potassium averaged 2.83 +/- 0.08 mEq/liter before and 3.73 +/- 0.06 mEq/liter after correction with potassium chloride, triamterene or both. Premature atrial contractions decreased in 6 patients, increased in 6 and remained unchanged in 4. There was no improvement in ventricular ectopic activity after plasma potassium correction. Ventricular ectopic activity improved in 5 patients, worsened in 10 and remained unchanged in 1. Ventricular tachycardia was not observed in either phase. Plasma magnesium remained normal throughout. The investigators conclude that in patients with uncomplicated hypertension, correction of diuretic-induced hypokalemia does not significantly reduce the occurrence of spontaneous atrial or ventricular ectopic activity.

Some wrong-way chemical changes during antihypertensive treatment: comparison of indapamide and related agents

Despite the beneficial therapeutic effects of antihypertensive drugs, some agents--particularly diuretics--seem to go in the "wrong direction" chemically. In fact, these changes could counteract some of the benefits resulting from lowering a patient's blood pressure. In the absence of hard evidence of the efficacy of long-term diuretic treatment of mild hypertension, we must be maximally sure that such therapy causes no harm. Thiazide and related diuretics have been associated with four distinct wrong-way chemical changes: increases in plasma concentrations of cholesterol, glucose, and uric acid, and a decrease in plasma potassium levels. The potential ramifications of such changes are well understood. The increase in circulating cholesterol, an established risk factor of myocardial infarction and stroke, is of particular concern--each year approximately one million hypertensive patients have myocardial infarctions. As a result, the search for safer and more effective diuretics must continue. Indapamide, a new antihypertensive drug, appears to meet these criteria. It is an effective diuretic with a considerable peripheral vasodilatory effect. Additionally, it does not appear to induce any significant change in circulating cholesterol, whereas chlorthalidone has been found to increase total cholesterol by 5%. Hydralazine is the only antihypertensive agent that seems to lower total cholesterol levels significantly. Neither indapamide nor hydralazine appears to affect plasma glucose levels; benzothiadiazines, however, have been found to induce an increase in circulating glucose.

Total body potassium in patients receiving chlorthalidone and metoprolol for hypertension

Measurements of potassium status were reviewed in 23 hypertensive patients receiving metoprolol either alone or in combination with chlorthalidone or chlorthalidone plus potassium over an average period of nine months. There was no statistically significant change in plasma potassium, total blood cell or total body potassium in patients on long-term metoprolol. Four subjects (17%) in the diuretic groups developed hypokalaemia (serum potassium less than 3.0 mmol/l) in the absence of significant falls in total blood cell or total body potassium. Thus the use of chlorthalidone plus potassium did not provide adequate prophylaxis against hypokalaemia even in metoprolol recipients. The study confirms that monitoring parameters of potassium handling is still necessary in beta-blocker recipients who also receive diuretics alone or in a fixed-dose combination with potassium.

Adverse reactions to pindolol administration

More than 1200 patients who received pindolol for the treatment of hypertension, angina pectoris, and various arrhythmias in studies conducted in the United States were included in the New Drug Application submitted to the FDA. Nearly 1000 of these patients received pindolol as monotherapy. The side effects reported were generally transient and of mild or moderate severity. The most frequently reported side effects seen after pindolol administration, compared to those seen after placebo, were in decreasing order of incidence: headache, dizziness, insomnia, muscle pain, fatigue, weakness, nervousness, joint pain, edema, nausea, and muscle cramps. Other side effects that occurred more frequently with pindolol than with placebo but at a rather low incidence induced weight gain, bizarre dreams, visual disturbances, lethargy, and diarrhea. Nasal congestion, throat discomfort, nocturia, impotence, pruritus, anxiety, hypotension, bradycardia, and heart failure occurred only rarely. Of the 323 patients who received pindolol alone for the treatment of mild to moderate hypertension, only 20 (6.2%) were withdrawn from the study because of side effects. Overall, 3.4% of the patients treated with pindolol were withdrawn because of side effects, most of which involved the central nervous system, that is, insomnia, anxiety, dizziness, and headache. However, a few patients manifested some edema and weight gain while receiving pindolol alone. Review of the side effects data did not reveal a tendency for the incidence of side effects to be dose related. One placebo-controlled, double-blind study designed to evaluate the fixed dosages of 15, 30, and 60 mg in the treatment of mild to moderate hypertension suggested that only the incidences of insomnia and nervousness increased with increasing doses. However, these side effects were generally transient and of mild or moderate severity. The evidence indicates that pindolol has an acceptable safety profile and that any side effects that appear are generally well tolerated and disappear with continued treatment.

Diuretic induced hypokalemia in the elderly

The effects of four commonly prescribed diuretics on serum potassium were assessed. One hundred sixteen elderly clinic patients, independently living, (mean age 74.3 years, range 60 to 99 years) were taking hydrochlorothiazide (HCTZ) (n = 40; mean daily dose, 53.9 mg), a combination of hydrochlorothiazide-triamterene (HCTZ-TMTR) (n = 38; mean daily dose, 1.28 capsules), furosemide (n = 20; mean daily dose, 38.0 mg), or chlorthalidone (n = 18; mean daily dose, 55.6 mg). Patients did not take more than one diuretic. No patients received potassium supplementation or had diseases affecting potassium balance. The study design was a nonblinded, noncrossover retrospective chart audit with chi-square analysis. All patients were counseled about reducing excessive sodium intake and using potassium-rich foods and salt substitutes, although compliance concerning these dietary factors was not assessed. Even though some comparisons of diuretics showed statistical significance, these differences probably are not clinically significant because all serum potassium values were above 3.0 mEq/L and no patient was symptomatic. This study supports the use of HCTZ as an initial antihypertensive diuretic; it is as efficacious as the other diuretics in this study, is less expensive, and usually does not cause clinically significant hypokalemia more often than do the other diuretics.

Clinical evaluation of labetalol alone and combined with chlorthalidone in essential hypertension: a double-blind multicentre controlled study

In a multicentre, double-blind, crossover, placebo-controlled study, the antihypertensive effect of labetalol 100 mg and chlorthalidone 10 mg, given alone or in combination, has been assessed in 32 hypertensive patients. The combination had a greater effect in reducing blood pressure than did its separate components. This was particularly evident after exercise. Heart rate increased during chlorthalidone therapy, decreased during labetalol therapy, and a summation effect was observed during treatment with the combination. In most cases additivity was observed, as no interaction between the single components was observed, except for heart rate after exercise, and for diastolic blood pressure in the upright position. No interaction was observed either in the biochemical indices or in the clinical side-effects.

Probable fatal cardiac dysrhythmia secondary to diuretic-induced hypokalemia

This case study describes the investigation of the sudden, unexpected death of a young, slightly hypertensive woman. She had a previous history pf serious hypokalemic-induced cardiac dysrhythmias associated with diuretic usage. Postmortem examination revealed no anatomic cause for her death. Her agonal plasma potassium, 5.4 mmol/L, seemed too low in light of her extreme acidosis, hypoxemia, and emergency treatment. Diuretic analysis indicated surreptitious ingestion of hydrochlorothiazide. Hypokalemia and the control of serum potassium concentration are discussed as are various modifiers of serum potassium.

Protean manifestations of neonatal hyperinsulinism

Endogenous hyperinsulinism is the leading cause of persistent hypoglycemia in children under one year of age. Classically, the symptoms of neonatal hypoglycemia have been referable to central nervous system dysfunction, with seizures described in nearly all patients. Our experience with eight neonates emphasizes the protean manifestations of this disease. One patient presented with a maternal history of diuretic use, and developed asymptomatic hyperinsulinism documented by provocative testing. The hyperinsulinism cleared after two weeks of medical therapy. This transient hyperinsulinism may have been secondary to use of a thiazide-type diuretic. A second patient presented, as a neonate, with a large abdominal mass but no seizure activity. Exploratory laparotomy revealed an 11 x 5 x 3 cm pancreatic tumor, which required splenectomy, 60% gastrectomy and duodenectomy for removal. Histologic examination demonstrated an insulin-secreting hamartoma. A third patient died suddenly without prior symptoms, and was found to have striking nesidioblastosis on pathologic examination. One infant presented with absence of the abdominal musculature (prune belly syndrome) and features of the Beck-with-Wiedeman syndrome, as well as profound hypoglycemia. Only three patients had seizures, and an additional patient had jitteriness. Pathologic diagnoses were: nesidioblastosis (n = 2); islet cell hyperplasia (n = 1); adenoma (n = 1); hamartoma (n = 1); transient hyperinsulinism (n = 1). One patient's pancreas showed areas of nesidioblastosis, islet cell hyperplasia, and a discrete adenoma in the region of the common bile duct. Careful diagnostic testing is essential in these patients, inasmuch as hypoglycemia is poorly tolerated by neonates and infants. Using the diagnostic algorithm presented here, all patients' endogenous hyperinsulinism was documented quickly and efficiently. Recognition of the broad spectrum of symptoms with which these patients may present is essential if serious neurologic sequelae are to be avoided.

Chlorthalidone plus reserpine versus hydrochlorothiazide plus reserpine in a stepped-care approach to the treatment of essential hypertension

The efficacy of thiazide-like chlorthalidone, 50 mg, plus reserpine, 0.25 mg, was compared with that of hydrochlorothiazide, 50 mg, plus reserpine, 0.125 mg, in a six-week double-blind study of 57 patients with essential hypertension unresponsive to diet control and diuretic (step 1) therapy. An average decrease in diastolic pressure of 17.0 mm Hg was attained at the end of week 6 by the chlorthalidone/reserpine group; the average drop in the hydrochlorothiazide/reserpine group was 18.6 mm Hg. Both treatment groups displayed greater blood pressure control each week than the preceding week; and, at the end of week 6, both groups attained control of at least 5 mm Hg below the diastolic goal pressure of 90 mm Hg. The chlorthalidone/reserpine-treated group required fewer titrations than the hydrochlorothiazide/reserpine-treated group. There were no reports of frequent or severe side effects with either drug.

Blood pressure response to a single daily dose of a clonidine-chlorthalidone combination

A single evening dose of a clonidine-chlorthalidone combination (Combipres) was compared with the usual twice-daily schedule in 11 patients with essential hypertension. No significant difference was found between the blood pressures recorded on the two regimens or between morning and afternoon pressures on the once-daily schedule. Only one patient did not maintain adequate blood pressure control. We suggest that some patients with essential hypertension can be adequately treated with a single daily dose of a combination of clonidine and chlorthalidone.

Drug-induced pancreatitis: a critical review

We critically reviewed the English language literature pertaining to drug-induced pancreatitis and attempted to determine whether the reported association between each drug and pancreatitis was valid. The following drugs seem to cause pancreatitis: azathioprine, thiazides, sulfonamides, furosemide, estrogens, and tetracycline. Less convincing, but suggestive evidence exists for: 1-asparaginase, iatrogenic hypercalcemia, chlorthalidine, corticosteroids, ethacrynic acid, phenformin, and procainamide. Evidence implicating other drugs is either inadequate or contradictory. Little is known about the pathogenesis of drug-induced pancreatitis. Ethanol was not considered in this review.

[Secondary hyperlipoproteinemia induced by diuretic therapy (author's transl)]

In order to study the degree and pathogenic aspects of the secondary hyperlipoproteinemia in patients under diuretic therapy we measured serum lipids, lipoproteins and the apoproteins A1, A2 and B in 12 adults after a 4 weeks placebo period and 6 weeks of treatment with chlorthalidon. There was a significant increase in atherogenic low density lipoproteins (LDL), (18%, P less than 0.05) whereas the high density lipoprotein-cholesterol Apo A1 and A2 levels were not significantly altered. The same was true for the total serum triglyceride- and the very low density lipoprotein- and LDL-triglyceride levels. The activity of lipoprotein lipase and hepatic triglyceride lipase was slightly but not significantly increased. A delayed LDL-catabolism seems to be the most probable pathogenic mechanism underlying the Chlorthalidon-induced hyperlipoproteinemia.

Hypokalaemia and diuretics: an analysis of publications

Published data have been used to define the characteristics of the fall in serum potassium concentration after taking diuretics and the efficacy of the various treatments given to prevent or correct it. The average fall is less after the usual doses of frusemide (about 0.3 mmol/l) than after the usual doses of thiazides (about 0.6 mmol/l) and is little influenced by the dose or duration of treatment. The fall with a given drug is the same in heart failure and hypertension, but the initial serum potassium concentration is higher in heart failure, so that the final value is lower in hypertension. In standard doses potassium supplements are less effective than potassium-retaining diuretics in correcting the hypokalaemia. The relation between the average serum potassium value and the frequency of low values (hypokalaemia) is such that very low values after taking diuretics are unusual in patients with hypertension or heart failure. Hypokalaemia would almost disappear as an important complication of diuretic treatment if it was defined as a value less than 3.0 mmol/l rather than as a value less than 3.5 mmol/l.

The antihypertensive and biochemical effects of hydrochlorothiazide/amiloride (Moduretic) versus chlorthalidone

In an open two-period crossover study hydrochlorothiazide/amiloride and chlorthalidone were compared with regard to their anti-hypertensive and biochemical properties in ambulatory patients with mild to moderate hypertension. Twenty-five out of twenty-six patients completed the study. In the chlorthalidone group plasma potassium was consistently lower than in the hydrochlorothiazide/amiloride group, the difference achieved significance at 8 and 12 weeks after the start of treatment. With regard to the hypertension and other parameters no statistically significant differences were found.

Atenolol and chlorthalidone in combination for hypertension

1 The hypotensive effect of single daily dosing with atenolol 100 mg and chlorthalidone 25 mg given alone or in combination has been assessed in a double-blind, crossover, placebo controlled trial in fifteen hypertensive patients. 2 Average lying blood pressures were: Placebo 155.4/103.9 mm Hg, atenolol 134.6/85.8 mm Hg, chlorthalidone 139.5/90.1 mm Hg, combination 127.7/82.5 mm Hg. 3 The effect of the combination therapy in reducing lying diastolic pressure compared with placebo (a fall of 21.4 mm Hg) was significantly less than the 31.9 mm Hg fall predicted from the sum of the individual effects (P = 0.01). 4 Observations on blood pressure at rest and under mental, isometric and bicycle ergometer stress were made pre-dose and post-dose for a 12 h period at the end of the last treatment period. 5 Lying blood pressure declined from the zero hour (pre-dose) reading on all treatments to a low at 15.00--18.00 h and then rose again. 6 The rise in systolic blood pressure after isometric exercise and mental stress was of a similar magnitude with all four treatment regimes. 7 Atenolol, alone and in combination with chlorthalidone, reduced the blood pressure and the pulse rate increase on exercise 2 h post-dose when compared with readings 24 h post-dose. 8 Once daily dosing with a combination of atenolol and chlorthalidone produced a fall in supine blood pressure over a 24 h period but the effect on exercise induced changes was not uniform over this period.

[The effect of diuretic therapy on serum lipoproteins: an undesirable effect?]

The effect of diuretics on serum lipids and lipoproteins was evaluated in 23 patients with essential hypertension treated with chlorthalidone for six weeks. Compared to placebo conditions, diuretic therapy significantly increased serum beta (+8%, p less than 0.05) or low-density-lipoprotein (LP) cholesterol (+17%, p less than 0.025). Since alpha-LP or high-density-LP cholesterol was unchanged or tended to decrease slightly, there was also an increase in the beta/alpha-LP (+26%, p less than 0.025) or low/high-density-LP cholesterol (21%, p less than 0.025) ratio. Serum cholesterol (+4%), triglycerides (+3%), phospholipids and the Apo-LP A-I, A-II and B were not changed significantly. Blood pressure and plasma potassium were decreased (p less than 0.01), blood volume and serum insulin were not changed significantly, and serum glucose was increased mildly. Plasma renin, aldosterone and norepinephrine levels rose significantly (p less than 0.05), while circulating epinephrine was unaltered. Alterations in LP were not related to variations in blood pressure, blood volume, plasma electrolytes or serum glucose or insulin; and they did not correlate with chlorthalidone-induced increases in plasma renin, aldosterone or norepinephrine. Treatment with certain diuretics may have an adverse influence on lipoprotein metabolism.

Prazosin and clonidine for moderately severe hypertension

In a single-blind comparative study of the cases of 30 moderately hypertensive patients, clonidine hydrochloride and prazosin hydrochloride had similar effectiveness in lowering blood pressure. Neither agent had significant effects on the renin-aldosterone axis. Addition of polythiazide to prazosin and chlorthalidone to clonidine notably increased the antihypertensive effect of both drugs. Serum cholesterol levels were observed to decrease when prazosin and clonidine were given and to rise when the diuretics were added to the regimen. The patients treated with clonidine were troubled by side effects, particularly drowsiness and dry mouth. Prazosin was better tolerated, with side effects tending to diminish with time. The "first-dose" effect was seen in two patients given prazosin, but it did not limit treatment. Both diuretics induced notable hypokalemia.

[Ergometry in the assessment of antihypertensive treatment (author's transl)]

A standardized ergometric test, suitable for recognizing abnormally high exercise blood pressures as well as the influence of hypotensive drugs on blood pressure, was employed in 13 of 28 hypertensives being treated with a combination of beta-receptor blockers (oxprenolol, 80 mg), a diuretic (chlortalidone, 10 mg), and a vasodilator (hydralazine, 25 mg). This combination was an effective antihypertensive measure with few side effects, particularly so in reducing elevated exercise blood pressures.

Acute stomatitis medicamentosa. Two case reports

Two cases of acute drug reaction with oral mucosal lesions and problems of diagnosis in the absence of specific clinical and histopathological findings are presented.

Dose response to chlorthalidone in patients with mild hypertension. Efficacy of a lower dose

A multicenter study of chlorthalidone was performed to determine the relative antihypertensive efficacy and side effects of doses lower than those usually recommended for therapy. After a 4-wk placebo control period 100 patients with mild hypertension were randomly assigned doubleblind to 12.5-, 25-, 50-, or 75-mg regimens of chlorthalidone or to placebo for 12 wk. The groups of patients taking 25, 50, and 75 mg had declines in blood pressure which were not significantly different from each other. Serum potassium decreased in the 50- and 75-mg groups but not significantly in the 25-mg group. We conclude that chlorthalidone, 25 mg daily, was at least as effective for hypertension as 50 and 75 mg with less perturbation of potassium. Use of smaller initial diuretic doses may provide equal efficacy with fewer side effects for many patients.

[Aldosteronism after hypokalemia in diuretic therapy of systemic arterial hypertension]

Twenty-two cases with essential arterial hypertension were studied in the final part of a chronic period of treatment with Chlortalidona and in the first 30 days after treatment. Measurements of the following parameters were made: 1) Change in the excretion of urinary aldosterone (aldo). 2) Change in the arterial pressure (delta P). 3) Transtherapeutic serum potassium (delta K). 4) Change in the Q-T (delta QT) in the electrocardiogram. The measurements were made 3 days after the suppression of the drug and afterwards every 3 to 6 days for a month. The correlation of the K and QT was significant (r = 0.63). The P did not correlate with the K nor with the aldo (r = 0.14). The aldo was -5.92 +/- 3.1 ug./24 hs (p = 0.01) in those cases responsive to the drug. The disappearance of the antihypertensive effect occurred at 9.61 +/- 3.7 days and correlated with the normalization of the QT (r = 0.83) and the serum potassium. The delta aldo correlated with K (r = 0.56) and normalized 6.7 days after the suspension of the drug. The secondary aldosteronism participates in the parogenia of the transtherapeutic hypokalemia although with a slightly significant correlation. The important correlation between the disappearances of the antihypertensive effects and the electrocardiographic signs of hypokalemia may dwell in changes which directly or indirectly exercise the diuretic in the intracellular metabolism of K without necessarily cousing an antihypertensive effect additive of the same hypokalemia.

Chlorthalidone-induced syndrome of inappropriate secretion of antidiuretic hormone

A 60-year-old woman who had been instructed to increase her water intake because of nephrolithiasis developed the syndrome of inappropriate secretion of antidiuretic hormone when treated with chlorthalidone for mild hypertension. Serum osmolality was 235 mOsm/kg with concomitant urine osmolality of 490 mOsm/kg. When serum sodium decreased to 110 mEq/liter, plasma antidiuretic hormone (ADH) was elevated at 30 pg/ml. The syndrome resolved when chlorthalidone was discontinued together with fluid intake restriction. Plasma ADH returned to normal (less than 0.5 pg/ml) after three days of treatment. The favorable outcome in this patient is attributed to early recognition of the syndrome, which might occur even with nonthiazide diuretics such as chlorthalidone.

Initial potassium loss and hypokalaemia during chlorthalidone administration in patients with essential hypertension: the influence of dietary sodium restriction

To investigate the initial potassium loss and development of hypokalaemia during the administration of an oral diuretic, metabolic balance studies were performed in ten patients with essential hypertension who had shown hypokalaemia under prior oral diuretic treatment. Chlorthalidone (50 mg daily) was given for 14 days. Six patients received a normal-sodium diet and four a low-sodium (17 mmol/day) diet. All patients had a normal initial total body potassium (40K). The electrolyte balances, weight, bromide space, plasma renin activity, and aldosterone secretion rate were measured. In both groups a potassium deficit developed, with proportionally larger losses from the extracellular than from the intracellular compartment. In the normal-sodium group the highest mean potassium deficit was 176 mmol on day 9, after which some potassium was regained; in the low-sodium group the highest deficit was 276 mmol on day 13. The normal-sodium group showed an immediate but temporary rise of the renin and aldosterone levels; in the low-sodium group renin and aldosterone increased more slowly but remained elevated. It is concluded that dietary sodium restriction increases diuretic-induced potassium loss, presumably by an increased activity of the renin-angiotensin-aldosterone system, while sodium delivery to the distal renal tubules remains sufficiently high to allow increased potassium secretion.