Pharmacotherapeutic stature of doxazosin and its role in coronary risk reduction

Otorhinolaryngological adverse effects of urological drugs

PURPOSE

To describe the otorhinolaryngological adverse effects of the main drugs used in urological practice.

MATERIALS AND METHODS

A review of the scientific literature was performed using a combination of specific descriptors (side effect, adverse effect, scopolamine, sildenafil, tadalafil, vardenafil, oxybutynin, tolterodine, spironolactone, furosemide, hydrochlorothiazide, doxazosin, alfuzosin, terazosin, prazosin, tamsulosin, desmopressin) contained in publications until April 2020. Manuscripts written in English, Portuguese, and Spanish were manually selected from the title and abstract. The main drugs used in Urology were divided into five groups to describe their possible adverse effects: alpha-blockers, anticholinergics, diuretics, hormones, and phosphodiesterase inhibitors.

RESULTS

The main drugs used in Urology may cause several otorhinolaryngological adverse effects. Dizziness was most common, but dry mouth, rhinitis, nasal congestion, epistaxis, hearing loss, tinnitus, and rhinorrhea were also reported and varies among drug classes.

CONCLUSIONS

Most of the drugs used in urological practice have otorhinolaryngological adverse effects. Dizziness was most common, but dry mouth, rhinitis, nasal congestion, epistaxis, hearing loss, tinnitus, and rhinorrhea were also reported. Therefore, doctors must be aware of these adverse effects to improve adherence to the treatment and to minimize damage to the health of patients.

Effect of administration and withdrawal of doxazosin on ambulatory blood pressure in patients with essential hypertension

The effect of both administration and withdrawal of doxazosin on patients with essential hypertension was evaluated by twenty-four-hour ambulatory blood pressure (BP) monitoring. Six hypertensive men were treated with doxazosin starting at 1 mg/day, and the dosage was titrated at weekly intervals up to a maximum of 8 mg/day. The twenty-four-hour BP profile was monitored noninvasively before treatment, in the fourth week of treatment, and on days 2 and 7 after the discontinuation of doxazosin. The average twenty-four-hour systolic and diastolic BPs (SBP and DBP) were lowered by doxazosin treatment and returned to the pretreatment levels within two days of doxazosin withdrawal. Doxazosin treatment produced a significant decrease in the daytime SBP and DBP but not in the nighttime BP values. The daytime BP decrease was no longer detected on days 2 and 7 after drug withdrawal. The twenty-four-hour pulse rate was not influenced by either doxazosin administration or discontinuation. The plasma norepinephrine concentration and plasma renin activity were increased by doxazosin treatment and were decreased by drug withdrawal. There was no rebound hypertension following doxazosin withdrawal. Thus, the present study using twenty-four-hour BP monitoring showed that doxazosin treatment reduced the daytime BP in patients with essential hypertension and that this reduction was abolished within two days after doxazosin discontinuation.

29-week doxazosin treatment in patients with symptomatic benign prostatic hyperplasia. A double-blind placebo-controlled study

In a placebo-controlled study, the safety and efficacy of the selective alpha 1-adrenoceptor-blocking agent doxazosin 4 mg once daily in the symptomatic treatment of benign prostatic hyperplasia (BPH) were evaluated. One hundred patients were primarily included in a 9-weeks study, and after this 75 patients accepted to continue in the present 20 weeks extension. Of the patients in the doxazosin-group (DG) 61% reported overall improvement against 53% in the placebo-group (PG)--(p = 0.56). In the DG, 49% of obstructive symptoms were improved compared to 27% in the PG (p < 0.01), and a reduction of 60% of irritative symptoms was found in the DG against 36% in the PG (p < 0.01). Daytime frequency was reduced by median 1.5 in the DG and remained unchanged in the PG (p < 0.01). Nocturia was reduced by median 1 and 0.5 respectively (p = 0.06). Maximum urinary flow rate (MFR) was improved by median 1.5 ml/s in the DG, while it deteriorated by median 0.5 ml/s in the PG (p < 0.05), Considering postvoid residual urine volume, cystometry variables (first sensation and bladder capacity), changes in sexual function and adverse events there was no difference between the two groups. In conclusion, doxazosin 4 mg once daily in long-term treatment of patients with BPH reduces both obstructive and irritative symptoms, daytime voiding frequency and although only slightly, significantly augments MFR without interference with sexual function and without other serious adverse effects.

Doxazosin treatment in patients with prostatic obstruction. A double-blind placebo-controlled study

The safety and efficacy of the selective alpha 1-blocking agent doxazosin 4 mg once daily in the symptomatic treatment of benign prostatic hyperplasia were evaluated in a randomized, double-blind and placebo-controlled 9-week study of 100 patients. By patients' overall assessment of voiding difficulties, 79% in the doxazosin group (DG) and 44% in the placebo group (PG) reported improvement (p = 0.001). In the DG, improvement was noted in 63% of obstructive symptoms compared to 32% in the PG (p = 0.015), whereas improvement was noted in 76% and 45%, respectively, of irritative symptoms (p = 0.12). Daytime frequency was reduced by 1.5 in the DG and increased by 0.3 in the PG (p = 0.001), and nocturia was reduced by 1.1 and 1.0, respectively (p = 0.12). Maximum urinary flow rate was improved by 1.5 ml/s in the DG, while it deteriorated by 0.3 ml/s in the PG (p = 0.11). Considering postvoid residual urine volume, cystometry variables (first sensation and bladder capacity) and adverse events there was no difference between the two groups. In conclusion, doxazosin 4 mg once daily is safe and effective in relieving symptoms in patients with BPH.

Selective alpha 1-adrenoreceptor blockers in the treatment of hypertension: should we be using them more?

It has become apparent in recent years that in the treatment of essential hypertension, reduction of blood pressure alone is not sufficient to reduce significantly the morbidity and mortality from ischaemic heart disease. Since the emergence of a multifactorial approach to the prevention of cardiovascular disease, the potential interaction between antihypertensive therapy and metabolic factors, such as control of blood glucose and lipid levels, has become an important consideration. Abnormal function of the sympathetic nervous system may contribute to both the initiation, or maintenance, of hypertension and the associated metabolic disturbances. The new generation of selective alpha 1-adrenoreceptor blockers, besides lowering blood pressure, appear to have favourable effects on lipid and glucose metabolism. The use of these drugs and their place in the treatment of hypertension are discussed.

Alpha 1 blockers. Safe, effective treatment for hypertension

Alpha 1-adrenergic blocking agents, used alone or in combination with other medications, are efficacious in the management of hypertension. They are safe and well tolerated, and they offer unique advantages. Their mechanism of action in lowering blood pressure targets elevated peripheral vascular resistance, which is the principal hemodynamic abnormality of essential hypertension. The alpha 1 blockers maintain cardiac output and blood flow to vital organs, and they do not affect renin release. These agents have beneficial lipid and metabolic effects and can improve left ventricular hypertrophy, theoretically having a positive impact on cardiovascular morbidity and mortality. The only drug interaction identified with the alpha 1 blockers is an increased hypotensive effect when they are combined with other antihypertensive agents. A further advantage of the alpha 1 blockers is that, because of the widespread location of alpha 1 receptors, the agents offer potential benefit for a number of disease states, including benign prostatic hyperplasia. They also provide an especially useful antihypertensive choice for middle-aged and elderly patients.

Doxazosin effects on insulin and glucose in hypertensive patients. The Finnish Multicenter Study Group

This study investigates the effects of prolonged doxazosin treatment on serum lipids, glucose, serum insulin, and blood pressure in hypertensive patients. Following 26 weeks of treatment with doxazosin, supine and standing blood pressures were significantly decreased at a final mean daily dose of 6.4 mg. Blood glucose levels were significantly lower at 26 weeks than after the initial placebo period (p less than 0.05) or after 4 weeks' treatment with doxazosin (p less than 0.001). There was a significant (p less than 0.05) decrease in serum insulin levels following 4 weeks of treatment, and a highly significant (p less than 0.001) decrease after 26 weeks. In addition, doxazosin produced a significant reduction in total cholesterol (p less than 0.05) and low-density lipoprotein (LDL) cholesterol (p less than 0.01) after 26 weeks, although the levels of high-density lipoprotein (HDL) cholesterol, very-low-density lipoprotein (VLDL) cholesterol, and triglycerides showed no significant change. There was a tendency for the ratio of HDL: total cholesterol to increase. The combined changes in blood pressure, blood glucose levels, serum insulin, and serum lipids favorably affect the probability of developing coronary heart disease (CHD).

A double-blind comparative study of doxazosin and prazosin when administered with beta-blockers or diuretics

The antihypertensive efficacy and safety of doxazosin (once daily) and prazosin (twice daily) were compared in patients with mild or moderate essential hypertension (diastolic blood pressure [DBP] 95 to 114 mm Hg) not adequately controlled by diuretics and beta-blockers. Doxazosin produced significantly greater mean reductions in standing (p = 0.01) and supine (p = 0.04) DBP than did prazosin; there were no significant between-group differences in either mean systolic blood pressure or heart rate. The overall mean daily doses for efficacy-evaluable patients were 4.7 mg of doxazosin and 6.7 mg of prazosin. Sixteen patients (84.2%) treated with doxazosin and 13 patients (56.5%) treated with prazosin were considered therapeutic successes (decrease in standing DBP greater than or equal to 10 mm Hg or to less than or equal to 90 mm Hg with greater than or equal to 5 mm Hg reduction from baseline). Of the 19 efficacy-evaluable patients treated with doxazosin, 15 (78.9%) showed improvement in the severity category of hypertension; an improvement in severity was reported in 14 patients (60.9%) treated with prazosin. Doxazosin produced a more favorable effect on serum lipid levels than did prazosin, although no statistically significant within- or between-group differences were observed. Most side effects experienced with either doxazosin or prazosin were mild or moderate and were tolerated or disappeared with continued treatment. The overall evaluation of toleration was excellent or good for 18 (90%) doxazosin- and 21 (91%) prazosin-treated patients. Clinical efficacy was rated as excellent or good for 16 patients (80%) treated with doxazosin and 15 patients (68%) treated with prazosin.

Efficacy of doxazosin in specific hypertensive patient groups

In practice, some of the major problems for the physician who treats hypertension are patients who are resistant to treatment or who have other complicating risk syndromes. Therefore the overall efficacy of an antihypertensive agent must include an assessment of effect in patients with serious ancillary problems. In this article, doxazosin is reviewed for its efficacy in the treatment of severe essential hypertension and specific complications or conditions of mild or moderate essential hypertension, namely, left ventricular hypertrophy, hyperlipidemia, noninsulin-dependent diabetes mellitus, renal insufficiency, pheochromocytoma, chronic obstructive pulmonary disease, peripheral vascular disease, and smoking. Doxazosin is particularly efficacious in many specific subgroups of patients with hypertension, and the results of relevant studies are discussed.

A multicenter study of doxazosin in the treatment of patients with mild or moderate essential hypertension and concomitant intermittent claudication

This study assessed the efficacy and safety of once-daily doxazosin in the treatment of patients (n = 19) with mild or moderate essential hypertension (sitting diastolic blood pressure [DBP] 95 to 114 mm Hg) and concomitant intermittent claudication (Doppler ankle/arm ratio of less than 0.80 and walking tolerance of less than 700 m on the treadmill). After 14 weeks of treatment with doxazosin, a significant (p less than 0.05) reduction in systolic blood pressure and DBP was observed. Mean blood pressures were reduced from 170/100 mm Hg at baseline to 161/93 mm Hg at the end of treatment. Minor changes in heart rate occurred, which with continued treatment were not statistically significant from baseline. In 12 of 16 (75.0%) efficacy-evaluable patients blood pressure was normalized (DBP to less than or equal to 90 mm Hg with an greater than or equal to 5 mm Hg reduction from baseline) with a mean daily dose of 7.6 mg/day. Doxazosin improved the hypertension severity category in 13 of 16 (81.3%) patients. The blood pressure ratios between both the thighs and arms and ankles and arms showed no statistically significant changes after treatment with doxazosin. Thigh blood flow at rest and the reactive hyperemia after 3 minutes of arterial occlusion did not change statistically. There was a tendency for pain-free distance to improve. Laboratory data were not significantly changed after treatment with doxazosin. Of the 19 patients studied, 5 reported mild or moderate side effects that were either tolerated or disappeared with continued treatment. No patient had therapy withdrawn and no patient required a dose reduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic assessment of doxazosin on left ventricular mass in patients with essential hypertension

A single daily dose of doxazosin taken during a 12-week period produced a significant reduction in blood pressure and left ventricular mass index in patients with mild or moderate hypertension. The systolic shortening coefficient was also increased and a trend in the improvement of ejection fraction, rate of circumferential fiber shortening, systolic contraction time, and preejective/ejective ratio was observed. No change in heart rate was recorded and no patients had side effects. The serum lipid profile was modified favorably, particularly with regard to the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio. By producing a reduction in blood pressure and left ventricular mass while favorably modifying the serum lipid profile, doxazosin produced a beneficial change in the overall coronary heart disease risk profile.

Preliminary results of the Norwegian doxazosin postmarketing surveillance study: a twelve-week experience

The study was designed to investigate the safety and efficacy of doxazosin in the control of blood pressure in general medical practice; the results presented concern the first 748 patients evaluated over a 12-week period. Blood pressure was significantly reduced after treatment with doxazosin (-13/-9 mm Hg), and heart rate was not significantly altered. In addition, doxazosin significantly reduced total cholesterol levels (-6.7%), reduced triglyceride levels (-19.8%), increased high-density lipoprotein cholesterol levels (+2.5%), and the high-density lipoprotein:total cholesterol ratio (+9.7%). The calculated risk of coronary heart disease was reduced by 20.5% over a 12-week period. Thirty-five percent of patients reported at least one side effect, and the number of patients experiencing severe adverse reactions was small. Twenty patients (2.7%) discontinued treatment because of adverse events, and 2.7% had the dose of doxazosin reduced.

Efficacy and safety of doxazosin in the treatment of patients with mild or moderate essential hypertension and elevated levels of cholesterol

In hypertensive patients, elevated serum cholesterol is a frequent and sinister additional coronary risk factor. Selective alpha 1-adrenoreceptor inhibitors appear to have the unique ability to control both risk factors. Forty-two patients, ages 42 to 65 years, including 21 men with sustained hypertension and elevated serum cholesterol levels, were included in a trial of monotherapy with doxazosin administered once daily (range, 1 to 16 mg). The influence of the drug on high blood pressure and elevated serum cholesterol was evaluated over a 28-week period, which consisted of a 4-week, single-blind placebo lead-in period, an open 10-week dose-adjustment period, and finally a 14-week maintenance period. Of the 39 efficacy-evaluable patients, 25 (64%) achieved adequate blood pressure control (diastolic blood pressure less than 90 mm Hg or a decrease in diastolic blood pressure greater than 10 mm Hg) at a mean daily dose of 2 mg of doxazosin. No persistent changes occurred in heart rate. In the 32 patients with evaluable lipid data, there were nonsignificant trends to an increase in high-density lipoprotein cholesterol and a reduction in total cholesterol, together with a significant reduction in serum triglyceride concentration. The combined changes in blood pressure and blood lipid levels resulted in a reduction of 36% in the calculated risk of coronary heart disease. Eleven patients reported side effects and four were withdrawn from therapy. These results confirm the antihypertensive and anticholesterolemic efficacy of once-daily treatment with doxazosin.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacotherapeutics of doxazosin

Doxazosin is the latest in a series of highly selective postsynaptic alpha 1-adrenoceptor inhibitors. It is readily absorbed, with high bioavailability and a relatively long plasma half-life, neither of which property is influenced by age. This accounts for the prolonged pharmacologic activity of doxazosin following a single oral dose. Its prime pharmacodynamic activity resides in its ability to counter sympathetic vasoconstriction of the systemic arteriolar resistance vessels and venous capacitance system, which enables the drug to target the major pathophysiologic abnormality in hypertension, i.e., the generalized systemic arteriolar constriction. The widespread vasodilation induced by doxazosin relieves both cardiac preload and afterload and, consequently, reduces left ventricular wall stress and myocardial oxygen consumption. In hypertension, doxazosin reduces blood pressure both at rest and during exercise by reduction of systemic vascular resistance without precipitating substantial reflex cardiac stimulation. The effects are maximal on the standing blood pressure between two and four hours after ingestion; due to doxazosin's relatively slow absorption, postural hypotension is infrequent. Its antihypertensive activity is maintained over 24 hours following a single oral dose, and the optimal dose range is 2 to 8 mg once daily. The antihypertensive efficacy of doxazosin has been shown to be comparable with that of other alpha-adrenoceptor inhibitors, beta-blocking drugs, diuretics, calcium antagonists, and angiotensin-converting enzyme inhibitors. In contrast to other conventional antihypertensive drugs, a unique feature of alpha-adrenoceptor-inhibiting drugs, including doxazosin, is their ability to reduce the plasma concentrations of triglycerides, total cholesterol, and low-density lipoprotein cholesterol and to increase high-density lipoprotein cholesterol concentration. This contrasts with the opposite effect on lipid levels induced by hydrochlorothiazide and atenolol seen in comparative studies. Side effects show no predilection for any organ system, and the overall incidence of such effects compares well with those of other commonly used antihypertensive drugs. This unique combination of antihypertensive efficacy and favorable effect on blood lipid levels indicates that once-daily treatment with doxazosin holds considerable promise in the treatment of hypertension, both from the point of view of its antihypertensive efficacy and also from its primary preventative potential.