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PubMedDate not supplied

[Xerostomia--a complication of antihypertensive drugs].

A hundred fifty six patients taking antihypertensive drugs and complaining for xerostomia were examined, in order to compare the incidence of xerostomia with age and sex of those patients. Xerostomia was recorded in 62.3% of the patients. In 74.2% of the patients taking sympatholytic drugs xerostomia was recorded, and in 64.3% of the patients taking diuretic drugs. Xerostomia seemed to be a complication of ageing in both sexes with a predilection in women. Finally, the incidence of xerostomia during the first six months was 32%.

Age Factors↗
PubMed1985

[Role of hypothalamic adrenoreactive structures in regulating the protective reaction to plasmin].

Electrical stimulation of the hypothalamic dorsomedial and wentromedial nuclei induced an activation of the coagulating system in rats. Plasmin in the vascular bed increased the electrical activity of medial and mamillary hypothalamic neurons, the activity coinciding in time with the maximal level of the blood hypercoagulating response. The activation does nor occur after plasminogen administration. The activation of the blood coagulating system is due to an excessive amount of plasmin in the blood and can be suppressed with sympatholytic agents. The plasmin-induced electrical activity is suppressed with aminasin whereas phentolamine administration does not affect the activity though no activation of coagulating system occurs. Absence of humoral hypercoagulating shift in the blood confirms participation of alpha-adrenoreception in peripheral efferents. The increased efferent sympathetic activity seems to be the cause of plasmin-induced hypercoagulation.

Animals↗
PubMed1985

Structural and functional adaptation in the rat myocardium and coronary vascular bed caused by changes in pressure and volume load.

The structural and functional characteristics of the myocardium and coronary vessels are major determinants of cardiac function. Both can be influenced by long-term hemodynamic changes, such as sustained alterations of pressure and/or volume load on the heart. The diastolic pressure-volume relationship of the left ventricle (LV) was evaluated in arrested isolated hearts from spontaneously hypertensive rats (SHR), Wistar Kyoto normotensive rats (WKY), pregnant and hyperthyroid SHR and WKY. Such measurements of the LV dimensions were also performed after antihypertensive therapy by hydralazine, felodipine, metoprolol and alpha-methyldopa. Cardiac function was studied in a perfusion system in which external work could be measured at various pre- and afterloads. Coronary flow and O2-extraction could also be determined. LV function was examined in young and aged SHR and WKY, in metoprolol-felodipine treated SHR and in two-kidney, one clip hypertension before and after its reversal by renal artery unclipping. The SHR LV in early established primary hypertension mainly showed eccentric hypertrophy, with increased LV enddiastolic volume for a given filling pressure and a marginal reduction of wall to lumen ratio (w/ri). Hence, a higher stroke volume could be delivered for a given myocardial fibre shortening. Nevertheless, when challenged by high afterloads, LV function in SHR was considerably augmented compared with WKY. The antihypertensive drugs used reduce arterial pressure in different ways, which may differently affect cardiac design. Generally, the results suggest that wall thickness was structurally adapted to keep w/ri balanced to the prevailing blood pressure, while internal radius was adapted to long-term changes in diastolic filling. Thus sympatholytic drugs which lowered arterial pressure by reducing cardiac output, induced a reduction of wall thickness at a minor change of internal radius, while drugs which reduced pressure by systemic vasodilation increased internal radius, thus reducing w/ri. Further, the results stress the importance also to consider the type of load which causes LV hypertrophy, and how rapidly it is imposed. Thus, renal hypertension was associated with reduced LV performance, despite considerable hypertrophy. However, on reversal of renal hypertension by unclipping, cardiac function was soon enhanced to match the degree of LV hypertrophy as in SHR. This suggests that the renal hypertensive state per se adds some cardio-depressive influence, possibly by inducing reversible changes of cardiac myosin isoenzymes, which tends to offset the improved ventricular performance inherent in LV hypertrophy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1988

Impact of antihypertensive therapy on blood pressure reactivity during mental stress.

The effects of baseline antihypertensive drugs or sympatholytic agents on the characteristic hemodynamic response pattern (i.e. increase in blood pressure and heart rate, decrease in total peripheral resistance) during emotional stress were examined. Middle aged male caucasian patients with hitherto untreated mild essential hypertension were given nitrendipine 10-20 mg per day, oxprenolol 160 mg per day or clonidine 75-300 micrograms per day until casual blood pressure was below 140/90 mmHg for at least three months. Blood pressure, heart rate and stroke volume was assessed, at rest and during emotional stress, before and during effective antihypertensive therapy. The increase in systolic pressure during stress was not attenuated by any of the drugs. Heart rate reactivity was lowest when patients received oxprenolol, but peripheral resistance during emotional stress was significantly increased. Clonidine had no unfavorable effects on the hemodynamic pattern during emotional stress but nitrendipine decreased peripheral resistance even more than the decrease in resistance observed during stress before initiation of therapy. If one accepts that antihypertensive therapy should not alter a physiological hemodynamic pattern to an unphysiological response, psychophysiological examinations seem to be valid in selecting suitable patients for the different alternatives in antihypertensive therapy.

Adult↗
PubMed1977

Preventing, detecting and managing adverse reactions of antihypertensive agents in the ambulant patient with essential hypertension.

The adverse reactions of antihypertensive agents are reviewed, including their clinical implications and suggested methods of preventing, detecting and managing them. The drugs discussed are: (1) diuretics--thiazides, furosemide, ethacrynic acid and spironolactone; (2) sympatholytics--reserpine, methyldopa, guanethidine, propranolol and clonidine; (3) vasodilators--hydralazine, prazosin and minoxidil. It is suggested that cooperative multi-disciplinary efforts should be undertaken to counteract the factors which contribute to improper use of antihypertensive agents.

Antihypertensive Agents↗
PubMed1987

Plasma catecholamine levels in the postoperative period in complication-free and "paralytic" ileus patients.

Plasma catecholamine concentrations were compared in a group of postoperative "paralytic" ileus patients and in another group of patients, who had undergone medium-size abdominal operations followed by uneventful recovery. The plasma epinephrine level was significantly in the former group, whereas no such difference was observed in the norepinephrine concentration. The data appear to confirm that the epinephrine released from the adrenal medulla appreciably contributes to the development of "paralytic" ileus. The therapeutically effective major tranquillizer and alpha-receptor blocking drug, trifluperidol, was found to reduce both epinephrine and norepinephrine levels in "paralytic" ileus patients. The decrease of the plasma epinephrine level was the higher, the greater its initial concentration. These findings seem to support the decisive role of increased catecholamine release in the development of postoperative motor inhibition ("postoperative" ileus) and also explain the success of sympatholytic treatment in such cases, i.e. the return of normal peristalsis.

Abdomen↗
PubMed1987

Predictions for the future of antihypertensive drug therapy.

Treatment of hypertension is changing rapidly because drugs with greater specificity are being developed and knowledge is evolving concerning factors that determine responses to available drugs. For almost a decade US physicians have relied on national guidelines called Stepped-Care. Step 1 calls for using either a diuretic or a beta blocker; in subsequent steps other drugs are added. Because of the new drugs and the new knowledge it is likely that Step 1 will soon be broadened to include many other drugs. The short-term changes in Step-1 will be based upon those factors now known to influence pressure responsiveness: age--young vs old; race--black vs white; type--renovascular vs essential; and severity--mild-to-moderate vs severe. In young hypertensives, much evidence suggests a dominant neurogenic component of central origin; therefore, a central sympatholytic drug or an alpha-beta receptor blocker seem to be preferable as firstline drugs. Hypertension, primarily systolic, in elderly patients responds well to diuretics or calcium channel blockers. Mild-to-moderate hypertension in blacks is particularly responsive to diuretics, while beta blockers are relatively ineffective. Renovascular hypertension is predominantly caused by increased angiotensin II, so converting enzyme (ACE) inhibition is indicated in unilateral stenosis. The hallmark of severe hypertension is vasoconstriction, so a vasodilator (nifedipine, minoxidil, or an ACE inhibitor) is indicated as first treatment, not a diuretic or a beta blocker alone. Long term changes will depend on development of drugs with specificity for newly, or better defined, pressor mechanisms.

Age Factors↗
PubMed1987

Effect of propofol anesthesia on baroreflex activity in humans.

Previous studies have shown that infusions of propofol, a new intravenous anesthetic, were associated with decreased arterial pressure and slow heart rates. To evaluate the role of baroreflex mechanisms in sustaining these conditions, the effects of two infusion rates of propofol (54 and 108 micrograms.kg-1.min-1) to supplement 66% nitrous oxide in oxygen anesthesia were studied in twelve ASA class I patients having a mean age of 34 years. Baroreflex control of heart rate was studied by perturbing the patients' arterial pressure with phenylephrine or sodium nitroprusside. Valsalva maneuvers were used to assess the response of the systemic arterial system. Steady state anesthesia at both infusion rates was not associated with decreased sensitivity of the baroreflex control of heart rate, but resetting of the reflex occurred to allow lower arterial pressures for a given heart rate than in the awake state. During propofol infusions at either rate, the diastolic pressure overshoot normally associated with the relief of raised airway pressure in the Valsalva maneuver was significantly reduced. It is concluded that propofol/nitrous oxide anesthesia is not associated with impairment of baroreflex sensitivity, but that central sympatholytic and/or vagotonic mechanisms enable low heart rates to be sustained despite decreased arterial pressures.

Adult↗
PubMed1986

[Cardiac protection and antihypertensive therapy: facts and theories].

After a brief introduction on the problems involved in the interpretation of long-term trials, the methods and the results of large clinical trials, on cardioprotection (defined as the ability of a drug to reduce mortality from all causes or fatal cardiovascular events) are reviewed, with the aim of providing useful clinical information for the treatment of the hypertensive patients. At the end of the review the author draws the following conclusions: The benefits of antihypertensive therapy reported in male patients suffering from severe hypertension are such that further controlled trials with placebo are not acceptable from an ethical point of view. The incidence of fatal and non fatal cardiovascular events is relatively low in mild uncomplicated hypertension but increases three-fold in the presence or organ involvement. A statistically significant reduction of mortality from all causes and of fatal cardiovascular events has been obtained in such patients by means of antihypertensive treatment in the Australian trial, contrary to the results of the MRC trial and the Oslo study. Furthermore, the HDFP trial has shown that mortality from all causes an fatal cardiovascular events are less frequent among patients in stepped care than among those in referred care. The EWPHE trial has demonstrated that antihypertensive treatment reduces non fatal complications and probably reduces mortality in elderly hypertensive patients. Diuretics, sympatholytics and beta-blockers have been used in the large trials on cardioprotection. When several trials prove the equivalence of drugs of different efficacy and safety, it is acceptable to extend the results obtained with such drugs to the therapeutic class they belong to. An example is represented by the results of the MRC and IPPPSH trials on cardioprotection with beta-blockers in male non-smokers suffering from mild-moderate hypertension.

Adult↗
PubMed1986

The diuretic dilemma and the management of mild hypertension.

Diuretics are presently used as antihypertensive medications as first-step monotherapy or in combination with adrenergic-inhibiting agents in the majority of hypertensive patients in the United States. A 30-year experience has demonstrated that blood pressure is lowered to as great or greater degree with diuretics than with many of the antihypertensive drugs presently available, including converting enzyme inhibitors, calcium entry blockers, beta- or alpha-adrenergic inhibitors, or centrally acting sympatholytic agents. Diuretics appear to be especially effective in the elderly and in black patients. All of the major hypertension clinical trials on which we base our decisions for treatment have employed diuretics as first-step therapy, with a reduction in morbidity and mortality. The debate concerning the long-term safety of diuretic therapy has focused on the United States Multiple Risk Factor Intervention Trial results and several papers suggesting that the lipid-raising or potassium-lowering properties of diuretics may produce adverse effects. Suggestions have been made that the use of other drugs without metabolic side effects may result in greater benefit with less risk, especially in the management of mild hypertension where the risk of the disease is not immediate or great. A review of the MRFIT and lipid data from long-term studies have failed to establish the "toxicity" of diuretic agents. In addition, recent studies have not confirmed previous observations that diuretic-induced hypokalemia increases ventricular ectopy or contributes to sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1987

[Indications and possibilities of blockade of the sympathetic nerve].

Treatment of chronic pain through permanent or temporary interruption of sympathetic activity is marked by great clinical success, but nevertheless there are rather skeptical reports about long-term results of these blocks as therapeutic measures. There are many symptoms and signs of chronic pain, while diagnosis is expensive, the pathogenesis is complex, and the etiology is generally due to multiple factors. Indications for sympathetic blockade depend upon the possible means of access, as in the cervicothoracic, thoracic, lumbar, or sacral regions. General indications are: symptoms not limited segmentally within peripheral body areas; pain resulting from microtraumata and lesions of peripheral nerve branches; and pain caused by intensified sympathetic tone with consequent circulatory disturbances. Peripheral circulatory disturbances are the most common indication for sympathetic blockade, as the block produces a vasomotor reaction that leads to increased capillary circulation. Pain caused by herpes zoster, sudden hearing loss, hyperhidrosis, and pseudesthesia can also be influenced by sympathetic blockade. There are several possibilities for reducing or interrupting sympathetic activity; for us, however, blocking of the sympathetic trunk is the most important. During the last 16 years we performed 15,726 sympathetic blockades on 2385 patients, which included: 3735 stellate ganglion blocks, 6121 blocks of the lumbar sympathetic trunk, 5037 continuous peridural anesthesias, 29 blocks of the thoracic sympathetic trunk, and 12 celiac blocks. In 792 cases sympathetic blocks were performed using neurolytic drugs, in most cases 96% ethyl alcohol and less often 10% ammonium sulphate. Other possibilities, such as enteral administration or infusion of sympatholytic drugs, were not taken into consideration; regional intravascular injection of guanethidine can be recommended, however.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗
PubMed1987

[Electrophysiologic and hemodynamic effects of the new anti-arrhythmia agent diprafenone].

Diprafenone is a new antiarrhythmic agent currently under clinical investigation, with close chemical similarity to propafenone. In this study, the electrophysiological and haemodynamic effects of the compound were investigated both in animals, by experiment, and in man. Diprafenone produces a dose-dependent prolongation of conduction in all parts of the conducting system. Lengthening of PQ-time is more pronounced than prolongation of QRS. The atrial and ventricular refractory periods are also significantly prolonged. There are no significant changes in the QT-time. Heart rate and aortic pressure are slightly decreased. The electrophysiological and haemodynamic profile of Diprafenone is similar to propafenone with respect to a dominant local anaesthetic activity and an additional beta-sympatholytic effect. However, with respect to the dose needed, the efficacy of the new drug appears to be significantly stronger. Diprafenone can be considered an effective antiarrhythmic drug for the treatment of supraventricular and ventricular tachyarrhythmias.

Animals↗
PubMed1986

[Dynamics of various characteristics of the sympathetic ganglia of animals subjected to chemical sympathectomy at high altitude].

The effect of high altitude hypoxia on the sympathetic nervous system was studied on desympathized rats. The degree of the sympathetic ganglion neurons destruction and catecholamine fluorescence were determined. The investigation showed an increase of catecholamine fluorescence in sympathetic ganglia in high altitude adaptation. 30-day administration of sympatholytic guanethidine at high altitude results in destruction of less ganglion neurons than at low altitude. At high altitude the rate of fluorescence of biogenic amines in unaffected cells remains high. After partial desympathization (7 days), the rate of neuron destruction diminishes and biogenic amines fluorescence increases along with the duration of preliminary adaptation.

Adaptation, Physiological↗
PubMed1985

The management of severe hypertension with minoxidil in a once-a-day treatment regimen.

We evaluated the antihypertensive efficacy of "once-a-day" minoxidil, given in conjunction with a diuretic and sympatholytic, and the effect of this simple regimen on patient compliance. Twenty-one severely hypertensive patients had their existing antihypertensive regimens changed to a single daily dose of chlorthalidone (50-100 mg) and either nadolol (160 mg) or reserpine (.25 mg) for a 3-week period. After stabilization on these two drugs, a single daily dose of minoxidil (2.5 mg) was added to each patient's regimen. Doses were titrated as necessary to achieve diastolic blood pressures of less than 90 mmHg. After 3 and 6 months of maintenance therapy, blood pressures were measured 24 hours after the previous day's dosing to evaluate the persistence of the antihypertensive effect. Twenty-four-hour blood pressure control was achieved on 76% of these occasions, and on at least one occasion in 90% of the patients. In addition, compliance was excellent.

Adult↗
PubMed1985

Cardiovascular and hormonal effects of clonidine in patients with essential hypertension and renal hypertension.

The putative role of the central nervous system in the maintenance of elevated blood pressure in patients with essential hypertension (EH) and renal hypertension [unilateral renal parenchymal disease (RPD) and unilateral renal artery stenosis (RAS)] was studied by investigating the cardiovascular and hormonal effects of the predominantly centrally acting sympatholytic agent, clonidine. Oral clonidine lowered blood pressure substantially in all three groups. Levels of plasma renin activity were unchanged in EH and RAS but progressively fell in RPD. Plasma noradrenaline levels fell in all three groups. Clonidine therefore reduced blood pressure to the same extent in three distinct groups of hypertensives, in two of which the initiating cause was undoubtedly renal. This indicates that, although the primary cause differed, a prominent factor sustaining hypertension may have been an increase or an inappropriate maintenance of central pressor mechanisms.

Adult↗
PubMed1985

Assessment of the antiarrhythmic profile of the new class I agent diprafenone.

The antiarrhythmic profile of the new compound diprafenone was evaluated using various dog models relevant to conditions in humans. In 8 animals, dose related effects on intracardiac conduction, atrial and ventricular refractoriness, fibrillation thresholds and on hemodynamics were determined. In this part of the study also the comparative actions of propafenone were assessed (8 animals). IN another 28 dogs the antiarrhythmic and antifibrillatory actions of diprafenone following short-term coronary occlusion and subsequent release were established. In additional 16 animals the effects of diprafenone on "delayed" reperfusion arrhythmias following release of coronary artery occlusion after 2 h and on stimulus-induced ventricular tachycardia in acute myocardial infarction were investigated. The results show: Diprafenone slows conduction through all parts of the AV-conduction system. The AH-interval is significantly prolonged, QRS-duration and ventricular repolarization are slightly lengthened, and both the atrial and ventricular refractory periods and fibrillation thresholds are markedly increased. Heart rate is slowed, aortic pressure and cardiac output are not significantly changed. Following acute short-term coronary artery occlusion, the incidence of ventricular fibrillation is reduced, and the drop in the ventricular fibrillation threshold is diminished. By contrast, the frequency of ventricular fibrillation after release of short-term occlusion is not influenced. "Delayed" reperfusion arrhythmias, however, are completely abolished, and initiation of ventricular tachycardia in myocardial infarction can be easily prevented. With a predominant local anesthetic mechanism of action and a potential additional beta-sympatholytic activity, the new compound displays close similarities to propafenone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Effect of imipramine on the vasomotor tone, blood supply and activity of the heart].

In tests conducted on anesthetized cats it was shown that imipramine used in doses of 1 and 3 mg/kg causes hypertension, increases the vascular tone in the kidneys and limbs. In doses of 5 and 10 mg/kg the drug provokes a short-lived (1--3 minutes) hypertension with a subsequent prolonged drop of the arterial pressure. The tonicity of the kidney and limb arteries changes in the same way as the arterial pressure, but the vascular tone in the heart only falls. In these doses imipramine blocks the adrenergic transmission of the excitation from the sympathetic nerve to the effector, e. g. produces a sympatholytic effect. Imipramine in a dose of 1 mg/kg intensifies the coronary circulation and then the oxygen absorption by the heart increases to a still greater degree. This is attended by the development of tachycardia, a greater cardiac output and an intensified contractility of the myocardium. In doses of 5 and 10 mg/kg imipramine protractedly reduces the cardiac ejection, coronary blood flow and significantly lowers the contractile function of the heart muscle.

Animals↗