Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The efficacy of labetalol in lowering blood pressure was assessed in 18 patients with chronic renal failure and hypertension. Before the start of labetalol therapy, all patients were receiving combined antihypertensive therapy, the most common being a beta-blocker and hydrallazine. Over the period of about four weeks labetalol was substituted for the prior therapy. 51Cr edetic acid (EDTA) estimations of glomerular filtration rate were performed before labetalol therapy, and then again after one and six months. Before the therapy with labetalol, 12 of the 18 patients had supine diastolic blood pressures of 100 mm Hg or more. At six months, 14 patients remained in the trial and, of these, only four had a supine diastolic blood pressure of 100 mm Hg or more. In the supine position there was a significant reduction of systolic, but not of diastolic, blood pressure. However, in the erect position there was a significant reduction both in systolic and in diastolic blood presure. Pulse rate did not vary significantly. Few side effects were encountered, transient postural dizziness being the most common side effect. Labetalol seems to be an effective substitute for the beta-blocker plus hydrallazine therapy. However, it is not as potent as minoxidil.
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PMID:Labetalol in the treatment of hypertensive renal patients. 2 15

The side-effect profile of labetalol was assessed in 34 patients with mild to moderate essential hypertension who had previously experienced side effects during beta-blocker therapy. The most frequently reported beta-blocker side effects were fatigue, impotence, cold extremities, and depression. After discontinuing their previous beta-blocker for 4 weeks, labetalol was titrated (100-400 mg b.i.d.) to achieve blood pressure control. Twenty-seven of 34 patients did not have a recurrence of a beta-blocker related side effect while receiving labetalol. The most common new side effect with labetalol was dizziness (3 patients). As judged by the attending physician and the patient, labetalol was better tolerated than conventional beta-blocker therapy in 30 of 34 patients (88%). Twenty-four of 34 patients (71%) preferred labetalol over previous therapy. Labetalol controlled blood pressure in 30 of 34 patients (88%). At equal antihypertensive doses, some side effects common to beta-blockers are seen less frequently with labetalol.
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PMID:Comparative tolerability of labetalol versus propranolol, atenolol, pindolol, metoprolol, and nadolol. 287 65

A case of intravenous labetalol in the treatment of a resistant hypertensive emergency is reported. Although there have been several reports of the use of oral labetalol in resistant hypertension, no intravenous administration in hypertensive emergency resistant to other drugs has been reported to date. A 36-year-old black female with BP of 270/160 mm Hg with complaints greater than one month's duration of dizziness, severe headaches, blurred vision, shortness of breath, vomiting, palpitations, flushing, agitation, diarrhea, weakness, and weight loss, was treated successfully with intravenous labetalol after she failed to respond to other established parenteral antihypertensive drugs. The patient received labetalol 20 mg iv bolus, and then 20 mg every ten minutes until a cumulative dose of 200 mg was attained. Labetalol produced a prompt but smooth reduction in BP without any reflex tachycardia or other adverse effects. Intravenous labetalol may be safe and effective for the management of rapid BP control in hypertensive emergencies resistant to other parenteral antihypertensive agents.
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PMID:Intravenous labetalol in the management of resistant hypertensive emergency. 360 97

The purpose of this study was to investigate the efficacy and safety of labetalol, an alpha and beta-adrenergic receptor blocking agent in 32 patients aged from 72 to 97 years (mean = 85 years) with blood pressure (B.P.) greater than or equal to 160/95 mmHg. This study was carried out in a double-blind, randomized, placebo-controlled design. After 6 weeks of treatment with labetalol (mean dose = 235 +/- 47.5 mg/day), the systolic pressure was lowered from 187 +/- 24 to 145 +/- 28 mmHg (p less than 0.001) and the diastolic pressure from 98 +/- 10 to 82 +/- 9 mmHg (p less than 0.001). Likewise, in the placebo group, both systolic and diastolic pressures were significantly reduced but the changes were significantly greater in the labetalol group, -33 +/- 26 versus -13 +/- 20 mmHg and -14 +/- 10 versus -8 +/- 14 mmHg respectively. Labetalol achieved B.P. control (160/95 mmHg) in 64% of the treated patients, compared to 40% in the placebo group. Two patients on labetalol discontinued their treatment due to side-effects (one bradycardia and one cutaneous reaction) compared with one patient on placebo (cardiac failure). Two other cases in the labetalol group had side-effects (one fatigue and one dizziness) which prevented increasing the treatment as necessary.
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PMID:[Arterial hypertension in the elderly. Double-blind study versus placebo of the efficacy and tolerability of an alpha-beta blocker: labetalol]. 382 57

Labetalol is a combined alpha- and beta-adrenoceptor blocking agent for oral and intravenous use in the treatment of hypertension. It is a nonselective antagonist at beta-adrenoceptors and a competitive antagonist of postsynaptic alpha 1-adrenoceptors. Labetalol is more potent at beta that at alpha 1 adrenoceptors in man; the ratio of beta-alpha antagonism is 3:1 after oral and 6.9:1 after intravenous administration. Labetalol is readily absorbed in man after oral administration, but the drug, which is lipid soluble, undergoes considerable hepatic first-pass metabolism and has an absolute bioavailability of approximately 25%. There are no active metabolites, and the elimination half-life of the drug is approximately 6 hours. Unlike conventional beta-adrenoceptor blocking drugs without intrinsic sympathomimetic activity, labetalol, when given acutely, produces a decrease in peripheral vascular resistance and blood pressure with little alteration in heart rate or cardiac output. However, like conventional beta-blockers, labetalol may influence the renin-angiotensin-aldosterone system and respiratory function. Clinical studies have shown that the antihypertensive efficacy of labetalol is superior to placebo and to diuretic therapy and is at least comparable to that of conventional beta-blockers, methyldopa, clonidine and various adrenergic neuronal blockers. Labetalol administered alone or with a diuretic is often effective when other antihypertensive regimens have failed. Studies have shown that labetalol is effective in the treatment of essential hypertension, renal hypertension, pheochromocytoma, pregnancy hypertension and hypertensive emergencies. In addition, preliminary studies indicate that labetalol may be of value in the management of ischemic heart disease. The most troublesome side effect of labetalol therapy is posture-related dizziness. Other reported side effects of the drug include gastrointestinal disturbances, tiredness, headache, scalp tingling, skin rashes, urinary retention and impotence. Side effects related to the beta-adrenoceptor blocking effect of labetalol, including asthma, heart failure and Raynaud's phenomenon, have been reported in rare instances.
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PMID:Labetalol: a review of its pharmacology, pharmacokinetics, clinical uses and adverse effects. 631 May 29

The antihypertensive effects of oral labetalol, a new alpha- and beta-adrenergic blocking agent, and metoprolol, a relatively beta1 selective adrenergic blocker, were evaluated in 91 patients with mild to moderate hypertension (standing diastolic blood pressure of 90 to 115 mm Hg) in a double-blind parallel group multicenter clinical trial. The effects of the two drugs on plasma lipids and lipoprotein fractions were also assessed. Following a four-week placebo phase, 44 patients were randomized to receive labetalol and 47 metoprolol. During a four-week titration phase, the labetalol dose was increased from 100 mg twice daily to a maximum of 600 mg twice daily to achieve a standing diastolic blood pressure of 90 mm Hg that was decreased by 10 mm Hg or more. Metoprolol was titrated from 50 mg to 200 mg twice daily. An eight-week maintenance period followed during which hydrochlorothiazide could be added. At the end of the maintenance phase, the doses of labetalol and metoprolol were tapered over a two to four day period after which patients received a placebo for one week. Blood pressure in the supine and standing position was measured at each visit. Labetalol and metoprolol both significantly (p less than 0.01) lowered the supine and standing blood pressure from baseline with no significant difference found between the two treatment groups. Both drugs lowered the heart rate; however, the rate-lowering effect was significantly greater with metoprolol (p less than 0.01). There were no significant effects of either drug on plasma lipids or lipoprotein fractions. Fatigue was the most frequently reported complaint with both drugs. Dizziness, dyspepsia, and nausea were more common with labetalol; bradycardia was more common with metoprolol. There was no blood pressure "overshoot" after withdrawing drug treatment; however, a heart rate "overshoot" was seen after metoprolol was tapered off and stopped. Labetalol is as safe and effective as metoprolol in the treatment of patients with mild to moderate hypertension.
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PMID:Multiclinic comparison of labetalol to metoprolol in treatment of mild to moderate systemic hypertension. 635

The long-term efficacy and safety of labetalol, an antihypertensive agent with combined beta- and alpha-blocking activity, were evaluated alone (number = 193) and in combination with a diuretic (number = 144) in an open-label multicenter trial of 337 hypertensive patients aged 21 to 75 years, including initially 205 (61 percent) men and 219 (65 percent) Caucasians. There were 219 (65 percent) mild, 85 (25 percent) moderate, and 33 (10 percent) severe hypertensive patients. Labetalol (100 to 1,200 mg twice a day) alone or in combination with a diuretic reduced the mean standing blood pressure by 13/11 and 25/16 mm Hg to 135/88 and 130/91 mm Hg, respectively (p less than 0.01), and supine blood pressure by 6/7 and 18/13 mm Hg to 141/86 and 138/90 mm Hg (p less than 0.01), respectively. Blood pressure reductions observed at one month were maintained after one year; 206 (62 percent) patients had 10 mm Hg or greater reductions and 184 (56 percent) patients were maintained at diastolic blood pressures less than 90 mm Hg. Most frequently reported drug-related side effects included fatigue (14 percent), dizziness (12 percent), nausea (11 percent), nasal stuffiness (8 percent), headache (4 percent), and male sexual dysfunction (14 percent). Side effects were generally of mild to moderate intensity and often transient. In addition, in 27 (8 percent) patients reversible asymptomatic transaminase elevations to greater than twice normal developed at some time during the study. In 13 (4 percent) patients these alterations resolved during continued labetalol therapy, but in five (2 percent) patients these marked elevations led to discontinuation of the drug. A total of 32 (9.5 percent) patients were terminated prematurely due to side effects (most commonly genitourinary or gastrointestinal) possibly attributable to the drug. These findings indicate that labetalol with or without a diuretic is a potentially effective, safe, and relatively well-tolerated long-term antihypertensive therapy.
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PMID:Multicenter clinical evaluation of long-term efficacy and safety of labetalol in treatment of hypertension. 635 1

Labetalol, a new alpha- and beta-adrenergic blocking agent, was administered to 57 patients with essential hypertension whose standing diastolic blood pressure was 105 to 120 mm Hg after three and four weeks of placebo therapy and greater than 90 mm Hg after three to four weeks of therapy with hydrochlorothiazide, 25 mg twice a day. Patients were then randomly assigned on a double-blind basis to receive either labetalol, 100 mg twice a day, or placebo combined with hydrochlorothiazide. Thereafter, the dose of labetalol was titrated weekly in both groups to a maximum of 400 mg twice a day to achieve a standing diastolic blood pressure of less than 90 mm Hg that was also decreased from the hydrochlorothiazide baseline by 10 mm Hg or more (therapeutic goal). Labetalol was abruptly discontinued after four weeks of treatment and patients were given hydrochlorothiazide alone for two additional weeks. After one week of labetalol therapy, 100 mg twice a day (added to hydrochlorothiazide), there was a significantly greater reduction in supine systolic/diastolic blood pressure (6/5 mm Hg, p less than 0.04/less than 0.03) and standing blood pressure (9/7 mm Hg, p less than 0.01/less than 0.01) than with placebo therapy (3/0.5 and 3/1 mm Hg, respectively). The blood pressure reduction in the labetalol-treated group was associated with a 4 and 5 beats per minute reduction in the supine and standing heart rates, respectively. The median labetalol dose required to achieve the standing diastolic blood pressure goal was 400 mg twice a day. After four weeks of labetalol treatment, the mean reduction in blood pressure from the hydrochlorothiazide baseline was 12/13 mm Hg (p less than 0.01/0.01) in the standing position and 8/8 mm Hg (p less than 0.01/0.01) in the supine position. These blood pressure reductions were accompanied by a mean reduction in heart rate of 7 beats per minute. The most frequently reported complaints other than thiazide-induced nocturia included dizziness, fatigue, nausea, rash, and/or pruritus. Most of these complaints were reported at a similar incidence while patients were receiving placebo or hydrochlorothiazide alone as when receiving labetalol with hydrochlorothiazide. After abrupt withdrawal of labetalol, no evidence of rebound hypertension was observed. Labetalol is a safe and effective step II drug when added to hydrochlorothiazide for the treatment of patients with moderate to moderately severe hypertension.
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PMID:Step II treatment with labetalol for essential hypertension. 635 2

Few studies have examined the characteristics of patients presenting with hypertensive urgency, factors contributing to their presentation, or their management. The time and cost associated with treatment are unknown. Retrospective analysis of 50 emergency department patients with hypertensive urgency (symptomatic blood pressure (BP) elevation focusing on systolic BP >180 mm Hg or diastolic BP >110 mm Hg) was performed. The hospital database was queried to determine the cost of the average treat-and-release visit. The mean age was 54.3+/-15.6 years; 64% were female; 46% were black; 90% had diagnosed hypertension. The mean presenting BP was 198+/-27.6/109+/-17.3 mm Hg; 66% had systolic BP >180 mm Hg, and 38% had diastolic BP >110 mm Hg. Initially, 30% were not on antihypertensives, and 28% were on monotherapy. Headache (42%) and dizziness (30%) were most frequently reported symptoms. Presentation was most often attributed to running out of medication (16%). IV and oral labetalol were given to 28% and 24% of patients, respectively. Fifty-six percent of patients had no change in baseline therapy at discharge. The average emergency department stay was 5 hours 17 minutes +/- 4 hours 27 minutes. The average cost for similar visits in 2004 was 1543 dollars per visit. Emergency department visits for hypertensive urgency are related mostly to noncompliance. Labetalol was the most frequently used therapy. Management in the primary care office could result in substantial cost savings.
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PMID:Characteristics and management of patients presenting to the emergency department with hypertensive urgency. 1640 84