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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies have indicated that some hypertensive patients, following a period of effective treatment with certain antihypertensive drugs, may experience prolonged normotension after drug withdrawal. We have studied the ability of carteolol, a nonselective beta-adrenoceptor antagonist with intrinsic sympathomimetic activity, to produce such remissions of hypertension. Thirty-four patients whose diastolic blood pressure was controlled at 90 mm Hg or less with carteolol monotherapy (2.5 to 5.0 mg/d for an average of 328 days) were randomized to a nine-month, double-blind, placebo-controlled drug-withdrawal trial. Those patients randomized to continue carteolol therapy had initially responded to carteolol treatment with reduction in blood pressure from 151 +/- 4/99 +/- 2 to 132 +/- 4/80 +/- 2 mm Hg. Those randomized to treatment with placebo had initially responded with blood pressure reductions from 154 +/- 4/97 +/- 2 to 137 +/- 4/81 +/- 2 mm Hg. Changes in mean systolic and diastolic blood pressure (mm Hg +/- SEM) from baseline during carteolol therapy to the final visit at nine months were not different for patients receiving placebo (13 +/- 5/6 +/- 4 mm Hg, recumbent; 11 +/- 6/4 mm Hg, standing) or carteolol (11 +/- 5/7 +/- 3 mm Hg, recumbent; 12 +/- 6/7 +/- 3 mm Hg, standing). The final mean recumbent diastolic blood pressure (86.9 mm Hg) was the same in both groups. Prolonged normotension may follow a period of carteolol treatment, again suggesting the potential importance of periodic withdrawal of antihypertensive medication.
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PMID:Remission of mild to moderate hypertension after treatment with carteolol, a beta-adrenoceptor blocker with intrinsic sympathomimetic activity. 304 36

A 1-year retrospective study of all serum profiles of patients with hypercalcaemia analysed at the Johannesburg Hospital was carried out to ascertain the causes of hypercalcaemia and physician awareness of primary hyperparathyroidism. Hypercalcaemia was found in 560 subjects (2.9% of 19,200), but in 147 of these (26%) this was not confirmed by repeat estimations. Malignant tumours were the commonest cause (38.4%) and accounted for the most severe hypercalcaemia (mean serum calcium 2.93 mmol/l). Renal disease resulted in significant hypercalcaemia, at times requiring parathyroidectomy. Drug-associated hypercalcaemia was usually mild and reversible on drug withdrawal. Although primary hyperparathyroidism occurred in 21.3% of cases, overall physician awareness of the disease was poor (39%). 'Incidental' profile hypercalcaemia (P less than 0.005) and hypertension (P less than 0.005) were frequent presenting features in this study. Renal disease (P less than 0.001) occurred infrequently.
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PMID:Hypercalcaemia in the Johannesburg Hospital. Differential diagnosis and physician awareness of primary hyperparathyroidism. 361 82

Guanfacine, 1 to 3 mg/day, and clonidine, 0.1 to 0.3 mg twice a day, were compared in a 24-week double-blind, randomized, parallel study of 42 patients with hypertension that was inadequately treated by chlorthalidone, 25 mg/day. Mean reduction of blood pressure was 18/9 mm Hg after guanfacine and 14/8 mm Hg after clonidine. To determine the incidence of rebound hypertension, subjects were hospitalized for 7 days during chlorthalidone therapy for collection of baseline data and once again immediately after abrupt withdrawal of the alpha-agonist after 24 weeks of dosing. Although blood pressure and heart rate rose significantly in both groups, the changes after clonidine withdrawal were greater and occurred earlier (day 2) than those after guanfacine withdrawal (day 4). Forty percent of the subjects receiving guanfacine and 64% of subjects receiving clonidine had diastolic blood pressure elevations greater than or equal to 10 mm Hg from baseline. There were increases in urinary norepinephrine levels in both groups after drug withdrawal, but these correlated poorly with blood pressure rise. Side effects after guanfacine were much the same as those after clonidine. Guanfacine taken once a day provides an effective and safe alternative to clonidine in the management of essential hypertension.
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PMID:Clonidine and guanfacine in hypertension. 388 7

Guanfacine (BS 100-141) (N-amidino-2-(2,6-dichlorophenyl)-acetamide hydrochloride) is a centrally acting alpha-adrenergic receptor agonist. A comparison of its anti-hypertensive effect with that of methyldopa was made in patients with essential hypertension. After a wash-out period of 8-10 days, 33 patients with hypertension of different degrees of severity were treated with guanfacine or methyldopa, both combined with clorexolone, in a randomized double-blind study extending over 8 weeks. Blood pressure was reduced significantly by both drug treatments, compared with the placebo. The incidence of side-effects with both drugs was low. Those that did occur decreased after adjustment of dosage. Guanfacine was clinically effective in all patients with various degrees of hypertension, but treatment with methyldopa was inadequate in 30% of patients even at maximum dosage. Up to 40 hours after abrupt drug withdrawal, no rebound hypertension was noted in the guanfacine group.
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PMID:The antihypertensive effect of guanfacine compared with methyldopa. 610 13

After discontinuation of antihypertensive medications, patients may experience symptoms associated with catecholamine excess, with or without a rapid rise in blood pressure; this is referred to as antihypertensive drug withdrawal syndrome. Though most often associated with the discontinuation of clonidine, this syndrome has been reported to follow the withdrawal of many other antihypertensives. Proposed mechanisms for the syndrome, depending on the drug involved, include enhanced activity of (1) the sympathoadrenal system, (2) the renin-angiotensin-aldosterone system, and (3) the thyroid hormones. The typical patient at risk is a younger person with severe hypertension, who has been on multiple drugs in high doses for a long period. Guidelines are provided for minimizing the occurrence of the syndrome and for treating the reaction, should it occur.
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PMID:Antihypertensive drug withdrawal syndrome. 612 20

A previously normal 58-year-old woman developed a widespread psoriatic rash and asymmetrical peripheral polyarthritis a week after beginning treatment with oxprenolol for hypertension. Skin and joint disease resolved simultaneously after drug withdrawal and have not recurred.
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PMID:Acute psoriatric arthropathy precipitated by oxprenolol. 623 60

Subsequent to receiving aversive classical conditioning, which led to a decelerative heart rate (HR) conditioned response (CR) and a pressor-depressor blood pressure (BP) CR, three separate groups of restrained rats received intravenous infusion of sodium nitroprusside (40 micrograms/mg/min) to lower baseline BP, phenylephrine (17 micrograms/mg/min) to raise baseline BP, or an equivalent volume of saline. Conditioning test trials during infusion revealed that hypotension produced by sodium nitroprusside eliminated the HR CR and transformed the BP CR into a pressor-only reaction. Hypertension produced by phenylephrine facilitated the HR CR and changed the BP CR to a pressor-only response on selected trials in which baseline BP increases and baseline HR decreases were within restricted limits. Following drug withdrawal, the HR CRs of both drug groups and the BP CR of the phenylephrine group were attenuated. The unconditioned responses to the shock unconditioned stimulus under phenylephrine were exaggerated and consisted of tachycardias and depressor BP changes, whereas under sodium nitroprusside reduced tachycardias and depressor activity occurred. The results suggested that the loss of the vagally mediated HR CR under sodium nitroprusside was due to baroreceptor-controlled inhibition of vagal discharge and that the enhancement of the HR CR under phenylephrine was due to baroreceptor-influenced facilitation of vagal discharge.
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PMID:Effects of drug-induced changes in resting blood pressure on classically conditioned heart rate and blood pressure in restrained rats. 648 16

The effect of long-term administration of propranolol (0.2 and 0.4 mg/kg-1 p.o.) and that of labetalol (2.0, 4.0 and 8.0 mg/kg-1 p.o. and 1 mg/kg-1 i.p.) on the development of hypertension was studied in female rats of SHR/N/Ibn strain. The experiment was started on 6-week-old animals. Rats received the tested drugs once daily between 11 and 12 o'clock. From the 29th day on (i.e. after the age of 10 weeks) the arterial blood pressure was measured bloodlessly twice weekly 2 hours before the daily dose of the drug. Labetalol given p.o. in a dose of 2 mg/kg-1 had no effect on the development of hypertension, while the doses 4.0 and 8.0 mg/kg-1 decreased the arterial pressure by about 4 kPa (30 mm Hg). After drug withdrawal a rapid rise was observed in the arterial pressure to values approaching the values recorded in control animals. In the animals receiving labetalol parenterally (1 mg/kg-1 i.p.) the blood pressure was significantly lower than in control rats. After drug withdrawal the blood pressure increased gradually, however, even on the 54th day of the experiment it was slightly below that in controls. Propranolol given orally in doses of 0.2 mg/kg-1 delayed the development of hypertension, while in the dose of 0.4 mg/kg-1 it prevented its development. After withdrawal of the lower drug dose the blood pressure remained for about 2 weeks at a level similar to the previous one, later on it increased steeply to the values observed in controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of labetalol and propranolol on the development of hypertension in spontaneously hypertensive rats. 653 80

The possibility exists that dietary modification may increase the number of patients who remain normotensive after drug withdrawal. In an effort to resolve this question, former Hypertension Detection and Follow-up Program Stepped Care participants (n = 496) were randomized into four major groups at the end of the programme (greater than 5 years antihypertensive therapy): controls (continue medication); discontinue medication, no dietary intervention; discontinue medication and weight loss; discontinue medication and reduce sodium. Groups 1, 2 and 4 were further divided into obese (greater than or equal to 120% ideal weight, and non-obese groups). The weight reduction group (greater than or equal to 120% ideal weight) lost 10.1 +/- 11 lbs without changing dietary sodium (n = 87). The sodium restriction group reduced urine sodium excretion from 145 to 97 mEq per day (n = 169). Sixty per cent of the weight loss group were normotensive at 56 weeks compared to 35% withdrawn from medication without dietary intervention. The highest 56 weeks success rates were in the mild non-overweight hypertensives on sodium restriction (78%), and the mild overweight hypertensives on weight reduction (72%). Randomization to either weight loss group or sodium restriction group increased the likelihood of remaining off drugs (adjusted odds ratio of 3.43 for the weight group and 2.17 for the sodium group (P less than 0.05). Age, severe hypertension greater than 5 years previous to entry into Dietary Intervention Study of Hypertension (DISH) or need for several drugs increased the chance of failure.
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PMID:Effect of dietary change on the return of hypertension after withdrawal of prolonged antihypertensive therapy (DISH). Dietary Intervention Study of Hypertension. 659 65

Diuretic therapy was withdrawn from 42 patients receiving modest drug doses for reasons other than hypertension, active heart failure and renal or hepatic oedema, with frequent assessment by clinical, biochemical and radiological methods for 12 weeks. Of 38 patients who could have completed the study, 27 (71%) did so without ill-effect. Eleven (29%) patients deteriorated clinically or radiologically, 7 within 2 weeks of discontinuing diuretics, and 1 of them died after acute pulmonary oedema and a haematemesis, despite intensive resuscitation. The outcome of drug withdrawal could be predicted in 35 of the patients using a multifactorial discriminant analysis but individual parameters had poor predictive value. The lack of demonstrable benefit in many patients and the incidence of adverse effects associated with long-term diuretic therapy suggest that withdrawal should be considered more often in this type of patient. However, there is a need for caution in this situation and withdrawal should only be attempted if close medical supervision and radiological examination of the chest are possible.
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PMID:Diuretic withdrawal--a need for caution. 662 73


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