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)

Terazosin is a post-synaptic alpha 1-adrenoceptor antagonist with a similar pharmacodynamic profile to prazosin. It differs from prazosin in having a longer duration of action, with an elimination half-life some 2 to 3 times that of prazosin, allowing the convenience of once daily administration. Moreover, its absorption from the gastrointestinal tract is more complete and predictable than that of prazosin which may facilitate dose titration. Terazosin therapy results in a significant reduction in blood pressure in patients with mild to moderate essential hypertension, with little influence on heart rate. The drug is an effective antihypertensive when administered as monotherapy or in combination with a range of antihypertensive agents including beta-blockers, diuretics and combinations of the two. In the few patients with congestive heart failure studied, terazosin produced an increase in cardiac output with a reduction in ventricular filling pressure and systemic vascular resistance, but no studies have been performed to assess the therapeutic potential of terazosin in this indication. Reductions in total plasma cholesterol and low density plus very low density lipoprotein cholesterol fractions have been reported after terazosin therapy, while high density lipoprotein cholesterol concentrations have tended to increase. Should such beneficial changes be confirmed in long term clinical studies they would suggest a therapeutic advantage of terazosin over some other antihypertensive drugs, particularly diuretics, which have been reported to adversely affect the plasma lipid profile. The most common side effects associated with terazosin treatment are dizziness, headache, asthenia and nasal congestion, but these are usually mild and do not require treatment discontinuation. Terazosin is normally administered once daily, starting at a dose of 1 mg/day and gradually titrating upwards as the blood pressure stabilises at each new dose, until blood pressure is adequately controlled or to a maximum dose of 20mg daily. First-dose syncope occurs rarely after terazosin, and can largely be avoided by giving the first dose at bedtime. Thus, terazosin offers a useful alternative to the drugs currently available for the management of mild to moderate essential hypertension either as monotherapy or in combination with other antihypertensive drugs.
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PMID:Terazosin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in essential hypertension. 288 69

A randomised double blind parallel group study was performed to compare the efficacy and acceptability of slow release nifedipine (maximum dose 40 mg twice a day) with those of atenolol (maximum dose 100 mg once a day) as single agents for the treatment of essential hypertension. Of 410 patients recruited almost exclusively from general practices in 22 centres in the United Kingdom 210 received nifedipine and 200 atenolol. Both drugs significantly reduced blood pressure, and control--a reduction of the diastolic pressure to less than 95 mm Hg--was obtained in about 65% of patients. Those who received nifedipine had more pronounced reductions in systolic pressure than those who received atenolol. One hundred and forty nine patients who failed to respond adequately to either atenolol or nifedipine in low doses were given both drugs once daily for eight weeks in a fixed combination capsule that contained atenolol 50 mg and nifedipine 20 mg. All patients showed further reductions in blood pressure, although those who were taking beta atenolol before the combination capsule had more pronounced reductions in systolic pressures. Twenty six patients (12%) were withdrawn because of adverse effects while taking nifedipine compared with 19 (10%) taking atenolol. Flushing and oedema were more common after the calcium antagonist, whereas diarrhoea and dyspepsia were more common after atenolol. The frequencies of headaches, dizziness, fatigue, and dyspnoea were equally distributed between the two groups. When the fixed combination capsule was taken side effects such as flushing and oedema continued. Nifedipine was more effective than atenolol in lowering systolic blood pressure, although neither drug used alone controlled the pressure of more than two thirds of the patients studied. When used in a fixed combination slightly better control of blood pressure was achieved with a lower dose of each drug.
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PMID:Nifedipine and atenolol singly and combined for treatment of essential hypertension: comparative multicentre study in general practice in the United Kingdom. Nifedipine-Atenolol Study Review Committee. 289 83

A double-blind, multicenter study compared the safety and efficacy of oral betaxolol 10 to 40 mg once daily (n = 68) with propranolol 40 to 160 mg twice daily (n = 73) in the treatment of mild to moderate essential hypertension. Both agents produced significant (P less than 0.01) and comparable reductions in mean supine systolic and diastolic blood pressures (7/11 mm Hg on betaxolol and 9/10 mm Hg on propranolol). Both betaxolol and propranolol significantly (P less than 0.01) reduced mean supine heart rate by 9 beats per minute. Patients achieved a more significant (P less than 0.01) reduction in blood pressure earlier (weeks 2 and 4 of the titration period) with betaxolol. By the end of treatment there was no significant difference in response between treatment groups. A higher incidence of central nervous system side effects (insomnia, bizarre dreams, depression, hallucinations, dizziness), however, was seen with propranolol than with betaxolol. Overall, the data show that in patients with mild to moderate essential hypertension, betaxolol 10 to 40 mg administered once daily is as effective as and better tolerated than propranolol 40 to 160 mg administered twice daily.
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PMID:Comparison of betaxolol, a new beta 1-adrenergic antagonist, to propranolol in the treatment of mild to moderate hypertension. 290 Dec 66

The long-term treatment of essential hypertension with terazosin, a new once-a-day alpha 1-adrenergic blocking agent, was evaluated in 364 hypertensive patients who received total daily doses of 1 to 40 mg for 3 weeks to 56 months. Consistent mean decreases in supine and standing systolic and diastolic blood pressures were observed throughout the study for patients treated with terazosin as monotherapy (supine, 9 to 12/10 to 13 mm Hg; and standing, 12 to 18/11 to 14 mm Hg) or in combination with other antihypertensive agents (supine, 12 to 16/12 to 15 mm Hg; and standing, 16 to 22/13 to 19 mm Hg). The most commonly reported adverse experiences were dizziness, headache, asthenia, cold symptoms, and nasal congestion. Adverse effects and metabolic disorders often associated with diuretics and beta blockers such as sexual dysfunction, hyperglycemia, hyperuricemia, hypokalemia, or adverse lipid effects were seen infrequently during long-term treatment with terazosin as monotherapy. Overall, terazosin was shown to be effective, safe, and well tolerated by most patients.
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PMID:Terazosin, a new selective alpha 1-adrenergic blocking agent. Results of long-term treatment in patients with essential hypertension. 290 Dec 67

In order to evaluate the usefulness of urapidil in the treatment of severe hypertension and in the long-term treatment of essential hypertension, two open multicentre studies were performed. In one study, 34 outpatients with diastolic blood pressure exceeding 105 mmHg following treatment with a combination of a diuretic and a sympatholytic or a diuretic and a beta-blocker were additionally given 15-60 mg urapidil twice a day for 8 weeks or more. The responder rate was 73.5%. The pulse rate did not change throughout. Side effects such as dizziness and malaise were observed in five patients (14.7%), but they were slight and did not require withdrawal of treatment. The other study included 95 outpatients with essential hypertension (World Health Organization stages I or II), 15-60 mg urapidil twice a day for 1 year or more in monotherapy (n = 48) or in combined therapy with a thiazide (n = 47). Under both therapies, diastolic blood pressure was reduced significantly at week 4, further reduced at week 12 and remained stable until week 52. Responder rates were 82.9% in monotherapy and 78.4% in combined therapy. Two patients (4.2%) taking monotherapy and six patients (12.8%) taking combined therapy were withdrawn due to inadequate blood pressure control or to side effects. These results indicate that urapidil is useful in severe and in long-term hypertension.
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PMID:Urapidil in patients with severe hypertension and in long-term treatment. 290 99

The aim of this multicentre, double-blind, randomised, controlled study was to evaluate the antihypertensive effect and to determine the response rates, safety and tolerability of 3 doses of carvedilol (25, 50 and 100 mg) compared with those of pindolol 15 mg, in ambulatory patients with mild to moderate uncomplicated essential hypertension. Mean supine diastolic blood pressure was the primary efficacy variable. 205 subjects between 23 and 70 years of age were randomly assigned to receive an oral dose of carvedilol or pindolol once daily for 13 weeks after a placebo run-in period of up to 4 weeks. Before administration of the study medication, blood pressure was recorded at each visit by use of the cuff method, and heart rate was counted. The results showed similar reductions in mean supine diastolic blood pressure among all 4 treatments after 13 weeks. Carvedilol showed a good and similar response rate of approximately 84% at all doses. Heart rate was not significantly changed. The number of patients having adverse experiences possibly related to drug therapy was 4, 16 and 15 with 25, 50 and 100 mg carvediolol, respectively, and 9 with pindolol 15 mg. Dizziness was the most common side effect reported for all medications. In conclusion, carvedilol 25 mg appeared to be the optimum dose in the present study, displaying a high antihypertensive potency with few side effects.
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PMID:Response rate with respect to the blood pressure-lowering effect of the vasodilating and beta-blocking agent carvedilol. 290 7

The role of serotonin in the pathogenesis of hypertension is interesting, and its investigation is much in vogue at present. This study compared the hypotensive effect of ketanserin, a specific 5-hydroxytryptamine receptor antagonist, with metoprolol in essential hypertension. On a double-blind basis, one treatment group (19 patients on ketanserin) was compared with another (21 patients on metoprolol). There was a significant reduction in diastolic blood pressure with both ketanserin and metoprolol (P less than 0,001). Side-effects were insignificant. One patient on metoprolol and 2 on ketanserin complained of dizziness. The dose of ketanserin was 40 mg twice a day and that of metoprolol 100 mg twice a day. Ketanserin does not appear to cause abnormal haematological values or biochemical adverse effects. It can be given to hypertensive patients with cardiac failure or bronchial asthma without adverse effects and may improve the peripheral vascular status of a hypertensive patient.
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PMID:A comparative study of ketanserin and metoprolol in essential hypertension. 293 40

Doxazosin is a new quinazoline derivative that, like prazosin, has selectivity for alpha 1-receptors. A three-way crossover, randomized, open study in 18 patients with essential hypertension was conducted to investigate the clinical pharmacokinetics of 2, 4, and 8 mg doxazosin at steady state. The pharmacokinetics of the initial 2 mg dose was also studied. Doxazosin showed linear pharmacokinetics. Increases in doses from 2 to 8 mg (steady state) produced proportional increases in doxazosin serum levels (maximum plasma drug concentration [Cmax] minimum plasma drug concentration [C min], and O-24-hour area under the curve [AUC(p-24)], whereas half-life (t1/2) (19.4, 18.7, and 19.7 hours, respectively), volume of distribution (3.4, 3.4, and 3.6 L/kg, respectively), clearance from serum (2.2, 2.2, and 2.1 ml/min/kg, respectively), and degree of protein binding (1.2%, 1.0%, and 1.0% unbound, respectively) were dose independent. Similar t1/2 and time to reach peak concentration (tmax) were obtained with 2 mg initial dose and 2 mg steady state. alpha 1-Acid glycoprotein levels were unchanged during doxazosin treatment. Doxazosin lowered supine and standing systolic and diastolic blood pressure. The blood pressure reduction was associated with an increase in heart rate. Peak hypotensive and tachycardic effects occurred 5.7 +/- 0.1 hours after administration, whereas Cmax was achieved at 2.4 +/- 0.7 hours (tmax). Greater decreases in systolic blood pressure and increases in heart rate were seen in standing than in supine position. The reduction in standing systolic and diastolic blood pressure with 8 mg was greater than with 2 mg (P less than 0.05); however, the increases in heart rate were not different. Dizziness, headaches, and dry mouth were the most frequent side effects. This study indicates that doxazosin shows linear pharmacokinetics between 2 and 8 mg and that because of its long t1/2, once-a-day administration should be adequate for the treatment of hypertension.
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PMID:Clinical pharmacology of doxazosin in patients with essential hypertension. 295 Oct 51

More than 5,000 primary-care physicians enrolled more than 22,000 patients with mild to moderate hypertension in a postmarketing study in which guanfacine hydrochloride, a centrally acting antihypertensive agent, was given for 28 days. The objectives of the evaluation were: (1) to obtain broad experience with guanfacine for the management of essential hypertension in a clinical practice setting; (2) to obtain information on patient acceptance of guanfacine, 1 mg HS, for the control of essential hypertension; and (3) to obtain more information on the drug's safety in clinical practice. Patients had to be at least 21 years of age, to be receiving a thiazide-type diuretic, and to have a sitting diastolic blood pressure of 95 to 114 mmHg. Women who were pregnant or lactating or planning to become pregnant during the evaluation were excluded. Blood pressure and heart rate were measured before guanfacine was started and at the completion of the study. Adverse on-therapy events were reported at the return visit. The average blood pressure in the general patient population decreased by 17/12 mmHg, that is, from 164/100 to 147/88 mmHg in four weeks. The magnitude of the reduction was not significantly influenced by age, race, sex, duration of hypertension, or the use of concomitant antihypertensive therapy. Adding guanfacine to another antihypertensive regimen resulted in mean reductions of 11 to 15 mmHg diastolic pressure, and the substitution of guanfacine for another antihypertensive agent resulted in mean reductions of 10 to 11 mmHg diastolic pressure. The most common side effect reported was dry mouth in 6% of patients, followed by dizziness, somnolence, fatigue, headache, and nausea, each reported in fewer than 3% of patients. More than 80% of the participants continued to receive guanfacine after the study. Of the total patient population, 7% discontinued guanfacine because of lack of efficacy, 10% because of side effects, and 3% for other reasons. The results of this large postmarketing study confirmed the results of controlled clinical trials conducted prior to marketing.
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PMID:A postmarketing evaluation of guanfacine hydrochloride in mild to moderate hypertension. 306 7

The blood pressure-lowering effect and tolerability of urapidil 120 mg once daily versus urapidil 60 mg twice daily was compared in 36 outpatients with newly diagnosed mild to moderate essential hypertension. Patients were enrolled in the study if they showed a favourable response to urapidil 60 mg twice daily at the end of a 2-week run-in as revealed by a first non-invasive 24-hour blood pressure profile. The patients were then randomly allocated to a 6-week double-blind treatment with either urapidil 120 mg once daily or urapidil 60 mg twice daily. Blood pressure, heart rate and adverse reactions were recorded every 2 weeks in the morning before drug intake. A second 24-hour blood pressure profile was taken at the end of this treatment phase. Compared with the pretreatment value after placebo run-in, urapidil 60 mg twice daily lowered supine morning blood pressure from 159/103 to 138/89. Urapidil 120 mg once daily lowered blood pressure from 161/102 to 139/90. The decrease in blood pressure was statistically significant within (p less than 0.001) but not between the treatment groups. Similar results were obtained with standing blood pressures. Side effects were observed in 2 patients with urapidil 60 mg twice daily (dizziness, intermittent lack of ejaculation) and in 7 patients with urapidil 120 mg once daily (5 with dizziness, and 1 each with headache and palpitations). Thus, urapidil 120 mg once daily lowers elevated blood pressure throughout a 24-hour period as effectively as 60 mg twice daily. Therefore, during long term therapy, the tolerability but not the efficacy of urapidil appears to be directly related to its peak serum concentrations.
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PMID:Efficacy of once-daily urapidil treatment in mild or moderate essential hypertension assessed by ambulatory 24-hour blood pressure monitoring. 340 55


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