Comparison of equal-weight oral dosages of verapamil hydrochloride and diltiazem hydrochloride in patients with mild to moderate hypertension

The clinical efficacy, safety, and tolerability of oral verapamil and diltiazem, at total daily dosages of equal weight, were evaluated in a placebo-controlled, double-blind crossover study. Thirty-six ambulatory patients with chronic, stable, mild to moderate hypertension (supine diastolic blood pressure of 94-116 mm Hg) received a dosage of either verapamil or diltiazem 80 mg t.i.d. as the hydrochloride salt for one week after an antihypertensive-drug washout period. Each then received 120 mg of the same drug t.i.d. for one week. After another two-week washout period, the patients were crossed over to the other drug. Each patient had a 12-lead electrocardiogram and measurement of supine and standing blood pressure weekly. In the 32 patients completing the study, low-dose verapamil reduced supine diastolic blood pressure (DBP) from a mean of 101.5 +/- 5.2 to 95.3 +/- 9.5 mm Hg; high dose verapamil reduced DBP to 90.9 +/- 7.4 mm Hg. Standing DBP was reduced to a similar degree. Diltiazem showed an almost identical effect: Supine DBP was reduced from a mean of 101.7 +/- 5.3 to 94.0 +/- 10.1 mm Hg with the low dose and to 91.0 +/- 8.6 mm Hg with the high dose, with similar effects on standing DBP. The high dose of both drugs significantly increased the QTc interval, and both doses of diltiazem significantly increased the PR interval compared with baseline. Both drugs exhibited consistent efficacy with minimal adverse effects. The electrophysiologic safety profile of verapamil was superior to that of diltiazem.     

Dose-titration study of alfuzosin,a new alpha1-adrenoceptor blocker,in essential hypertension

Summary An open, dose-titration study of alfuzosin, a new selective post-synaptic alpha₁-adrenoceptor antagonist with additional direct vasodilator properties has been performed. After a 3-week runin placebo period, 12 patients with essential hypertension received alfuzosin 5 mg oral b.d., and then the dose was doubled every week, up to a maximum of 20 mg q.i.d. if the supine diastolic blood pressure was >90 mm Hg. The study lasted for 4 weeks.Supine blood pressure (SBP) decreased from 160/102 (Day 0) to 148/89 mm Hg and upright blood pressure (UBP) from 151/102 (Day 0) to 137/84 mm Hg. Alfuzosin did not cause any significant change in supine or upright heart rate.In addition, after the first dose of alfuzosin, supine and upright blood pressure and heart rate (SHR and UHR) were measured every 30 min for 5 h. The fall in blood pressure was significant after 90 min and it lasted up to the 5th hour; the maximum effect was observed after 3 h: SBP decreased from 159/103 (time 0) to 137/84 mm Hg and UBP from 150/102 (time 0) to 123/79 mm Hg.SHR was increased from 72 (time 0) to 81 beats/min at the 5th hour and UHR from 87 to 101 beats/min at the 4th hour.A weak but significant correlation was observed between the hypothensive effect 12 h after drug intake and the plasma concentration of the drug at that time. A 10% decrease in supine diastolic blood pressure was found at a drug plasma concentration higher than 7 ng/ml.Nine of the 11 patients reached the end-point (supine diastolic BP90 mm Hg) at the end of 28 days: 1 at the dose of 5 mg b.d., 6 at 10 mg b.d. and 2 at 20 mg q.i.d. At the high dose they both complained of palpitations. Two other patients complained of mild and transient palpitations at lower doses.     

Pharmacokinetic properties and antihypertensive efficacy of once-daily diltiazem.

The pharmacokinetic and clinical characteristics of a once-daily formulation of diltiazem are described. In a 20 subject, 5 day, steady-state pharmacokinetic study, 120 and 240 mg of once-daily diltiazem were bioequivalent on a dose-adjusted basis and were bioequivalent to a conventional reference product administered four times daily. The conventional formulation showed marked diurnal variation in its pharmacokinetics. Plasma concentrations following its administration at 2100 and 0300 h were significantly lower than following administration at 0900 and 1500 h. One hundred forty-four hypertensive patients completed a 16 week placebo-controlled, dose-titrated study examining the effects of once-daily diltiazem at doses of 120, 240, and 360 mg. Blood pressure was measured manually and (in 121 patients) by ambulatory evaluation. Following dose titration, diltiazem given once daily reduced blood pressure with significant effects present at 24 h following drug administration. Ambulatory blood pressures were lower than those measured manually and data from the manual measurements demonstrated a placebo effect suggested to result primarily from investigator bias. The placebo-adjusted reduction in blood pressure 24 h following a dose of diltiazem was approximately 5 mm Hg and was comparable for manual (supine and standing) and ambulatory measurements. Diltiazem was well tolerated. The only significant findings were of tiredness/dizziness (9 patients of 144) or oedema (also 9 of 144). The incidence of headache was not different than placebo. On both pharmacokinetic and pharmacodynamic grounds, the results indicate that diltiazem can be formulated in a manner suitable for once-daily antihypertensive use.     

Pharmacokinetics of verapamil in patients with hypertension

Summary Twelve hypertensive patients (WHO Stage I-II) were given oral verapamil (Isoptin) b.d. or t.d.s. as long-term treatment. The pharmacokinetics of verapamil and norverapamil were studied both after single and b.d. and t.d.s. doses of verapamil 240, 360 or 480 mg daily adjusted according to the blood pressure response. The apparent oral clearance of verapamil was decreased after both the twice and thrice daily dosage regimens (1.38 and 1.841/min, respectively) as compared to the single dose (4.39 l/min). The plasma half-life of verapamil was increased from 3.34 h (single dose) to 4.65 h (b.i.d.). Decreased elimination of norverapamil was also found after multiple doses of verapamil, as shown by an increase in the adjusted AUC of norverapamil (adjusted to a verapamil dose of 80 mg), namely from 574.9 h·ng·ml^–1 (single dose) to 1172 h·ng·ml^–1 (b.d.) and to 841 h·ng·ml^–1 (t.d.s.). The plasma half-life of norverapamil increase from 5.68 h to 7.34 h during twice daily dosing. During thrice daily verapamil, no increase in plasma half-life was found either for verapamil or norverapamil, probably due to the relatively short sampling time (6 h). The plasma concentration of verapamil and the reduction in supine systolic and diastolic blood pressure were correlated. The mean decrease in supine systolic blood pressure was 5.8 mm Hg per 100 ng verapamil/ml plasma, and for diastolic pressure 2.9 mm Hg per 100 ng verapamil/ml plasma. The mean steadystate plasma concentrations of verapamil were similar after twice and thrice daily dosing regimens, which agrees with the clinical observation that blood pressure control in hypertensive patients is as good after verapamil b.d. and t.d.s.     

Sustained-release diltiazem: duration of antihypertensive effect

The antihypertensive activity of a sustained-release preparation of diltiazem (given each 12 hours) was assessed in 96 patients with supine diastolic blood pressure (BP) between 95 and 110 mm Hg in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial comparing optimally titrated doses of diltiazem and placebo. The aim was to assess the onset of action as well as the extent and variability of BP control of this formulation during the 12-hour interval. Diltiazem was titrated from 120 mg bid to 180 mg bid as necessary to lower BP. At baseline, on the first day of titration, and at the end of 8 weeks, BP was evaluated at 0, 1, 2, 3, 4, 5, 6, 8, 10, and 12 hours after dosing. The onset of action was within 2 hours, and the effect was maintained throughout the 12-hour period. Mean BP for the diltiazem group at baseline was 154/101 mm Hg. At week 8, BP was 148/93 mm Hg at hour "0" (P less than .02 and P = .0001 for systolic and diastolic BP vs. placebo), 139/84 mm Hg at the nadir at hour 5 (P = .0001), and 149/91 mm Hg at the end of the 12-hour period (P less than .02 and P = .0001 for systolic and diastolic BP). Diltiazem was significantly more effective than placebo (P = .0001) with 50% of patients controlled to a diastolic pressure of less than 90 mm Hg at 7 of the 10 evaluation points, including the evaluation point of 12 hours post-dose.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relevance of genetic polymorphism in drug metabolism in the development of new drugs

Summary Cuff blood pressure data has suggested that the calcium channel antagonist nisoldipine has full twenty four hour efficacy. To test this, 24 h ambulatory intra-arterial blood pressure monitoring was performed on 18 untreated hypertensive subjects (12 men, 6 women) (cuff blood pressure >150/95 mm Hg) before and after chronic treatment with 10–20 mg oral nisoldipine taken daily at 08.00 h. Twelve patients completed the study, six being withdrawn, four because of side-effects. After baseline intra-arterial monitoring patients were started on 10 mg nisoldipine daily. Response was assessed by cuff pressures taken 24 h after dosing at fortnightly intervals, and if not controlled (<150/95 or at least 10 mm Hg reduction in diastolic BP) the dose was increased to 20 mg. All patients received at least six weeks' therapy before the second intra-arterial blood pressure monitoring.There was a slight but insignificant reduction in mean daytime heart rate of 3 beats·min^–1. Mean significant reduction in daytime systolic and diastolic BP was 19 mm Hg and 13 mm Hg respectively but there was no significant mean night-time reduction. By comparison 8 out of 12 patients were apparently controlled more than 24 h post dose according to cuff pressures.This study suggests that this formulation of nisoldipine does not control blood pressure over a full 24-h period, and emphasises the importance of 24 h ambulatory monitoring in assessing the efficacy of once-daily antihypertensive agents.     

Conventional and controlled release diltiazem

Diltiazem CR tablets 120 mg b.i.d. for 1 week were compared with plain tablets 60 mg q.i.d. in 13 healthy male volunteers in a study of pharmcokinetic variables. Their antianginal efficacy was also compared in 23 patients with stable angina pectoris who were already on metoprolol. Both studies were of randomised, cross over design, and the clinical study was double blind.The pharmacokinetic variables of the two formulations were very similar except for the longer t_max of 4.4 h for diltiazem CR in comparison to 2.9 h for the plain tablets. The mean relative bioavailability of diltiazem CR in comparison with plain tablets was 1.14.The clinical study showed that after four weeks on diltiazem CR 120 mg b.i.d. or diltiazem plain tablets 60 mg q.i.d. in addition to metoprolol, there were significant decreases in weekly anginal attacks from 11 to 5 attacks/week, the number of nitroglycerin tablets consumed from 6 to 3 tablets/week, and an increase in the maximum workload from 116 to 126 and 123 W for diltiazem CR and plain diltiazem tablets, respectively, as compared to placebo. Five of the patients were angina free during diltiazem treatment. No difference in antianginal efficacy between the two preparations was seen. It was concluded that CR 120 mg b.i.d. appears bioequivalent to plain diltiazem tablets 60 mg q.i.d.     

Atenolol-nifedipine combinations compared to atenolol alone in hypertension: efficacy and tolerability.

1. In a double-blind, randomised, three-way-crossover study, 25 patients with sitting diastolic blood pressure between 95 and 120 mm Hg (Phase V) after 4 weeks' run-in on atenolol 50 mg twice daily, received atenolol 50 mg twice daily alone, atenolol 50 mg plus nifedipine 20 mg each twice daily and atenolol 50 mg plus nifedipine 40 mg each twice daily in three treatment periods each lasting 4 weeks. 'Washout' periods were not included. 2. The two combination treatment regimes lowered the 12 h post-dose blood pressure more effectively than did atenolol alone, but the high dose nifedipine combination was no more effective than the low dose nifedipine combination. Sitting systolic BP (+/- s.e. mean) at the end of each period was 174 +/- 5 mm Hg after the atenolol run-in, 170 +/- 5 mm Hg with atenolol alone, 156 +/- 5 mm Hg with the low dose combination and 158 +/- 4 mm Hg with the high dose combination. Corresponding diastolic BP readings were 106 +/- 2 mm Hg, 106 +/- 2 mm Hg, 97 +/- 2 mm Hg and 99 +/- 2 mm Hg respectively. 3. Side-effects tended to occur less commonly with the low dose of the fixed combination than with atenolol alone. An increased number of side-effects occurred with the 40 mg twice daily doses of nifedipine, particularly flushing/erythema, oedema of the ankles/feet, and a hot feeling in the legs. These differences did not reach significance. 4. Overall compliance was good (98 +/- 0.7 s.e. mean %) and was similar within the different treatment regimes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sustained antihypertensive activity of diltiazem SR: double-blind, placebo-controlled study with 24-hour ambulatory blood pressure monitoring.

A new polymeric matrix technology provides a sustained-release formulation of diltiazem hydrochloride (diltiazem SR) suitable for once-daily therapy. The efficacy and safety of diltiazem SR were evaluated in a multicenter, randomized, double-blind, placebo-controlled, parallel-group study. After a single-blind, placebo lead-in period, 275 patients with mild to moderate essential hypertension were assigned to receive placebo or diltiazem SR 120, 240, 360, or 480 mg once daily for 4 weeks. The efficacy evaluation was based on office and 24-hour ambulatory blood pressure monitoring. Twenty-four hours after the last dose in the 4-week, double-blind treatment period, the mean reduction from baseline in supine diastolic blood pressure ranged from 5.1 to 10.6 mm Hg in the diltiazem SR 120- to 480-mg groups, resulting in a significant linear trend across all treatments (P less than .001). Reductions in systolic blood pressure were similar. Ambulatory blood pressure monitoring, performed in 138 patients, confirmed the dose-response relationship and showed consistent antihypertensive activity throughout the 24-hour dosing interval. The percentage of patients reporting adverse events was similar in the placebo- and active-treated groups. The results of this study indicate that diltiazem SR is well tolerated, lowers blood pressure in a dose-related manner, and provides sustained activity throughout the 24-hour dosing interval.     

Open comparative study to assess the efficacy and safety of two calcium antagonists: amlodipine and diltiazem in the treatment of symptomatic myocardial ischemia

The efficacy and safety of amlodipine (5-10 mg once daily) and diltiazem (30-60 mg three times daily) were compared in 40 patients with symptomatic myocardial ischemia. A 2-week placebo run-in period was followed by 10 weeks of open treatment with amlodipine (n = 20) or diltiazem (n = 20). Concomitant treatment with other antianginal drugs (except other calcium antagonists) was permitted throughout the study. The baseline blood pressures were 166/93 and 160/91 mm Hg for the amlodipine group and diltiazem groups, respectively. Amlodipine (mean final daily dose of 9.25 mg) reduced blood pressure by - 27/-11 mm Hg compared with a reduction of - 17/-8 mm Hg for diltiazem (mean final daily dose of 180 mg), with no significant effects on heart rate. A significantly greater reduction in the mean rate-pressure product was observed after amlodipine (-20.8%) when compared with diltiazem (-13.1%) (p < 0.05). Amlodipine reduced the mean weekly angina attacks to zero after 6 weeks of treatment (baseline of 3.4 attacks/week) compared with a reduction from 3.3 to 0.35 attacks/week after 10 weeks of treatment with diltiazem. The amlodipine group had a reduction in mean nitroglycerin consumption from baseline of 1.1 mg/week to zero by week 6, whereas the diltiazem group had reduced mean weekly intake from 0.9 to 0.1 mg at the end of the study. The overall assessment of clinical efficacy was excellent for 100% of amlodipine patients compared with 40% of diltiazem patients. The high-density lipoprotein cholesterol/total cholesterol ratio increased by 15.8% with amlodipine compared to diltiazem, which produced a 4.5% decrease. Amlodipine decreased triglycerides by 7.1% compared to 4.5% with diltiazem. The incidence and severity of side effects was comparable for both treatments. Amlodipine once daily was effective and well tolerated in the treatment of patients with symptomatic myocardial ischemia and was comparable with diltiazem three times daily.     

Factors in hydrazine formation from isoniazid by paediatric and adult tuberculosis patients

Summary The antihypertensive efficacy of sustained-release nicardipine compared to placebo as third-line therapy has been assessed by ambulatory blood pressure monitoring in severly hypertensive patients with clinically unsatisfactory blood pressure control on 50 mg hydrochlorothiazide o.d. and 75 mg captopril b.d. Forty-two patients, 31 m and 11 f, with supine diastolic blood pressure 95–115 mm Hg after a 4 week run-in period on open hydrochlorothiazide and captopril, were randomly allocated to sustained-release nicardipine 45–60 mg/d or placebo.At a visit to the clinic blood pressure and heart rate were measured 12 h after the evening dose by a trained observer unaware of the treatment. Twenty-four hour ambulatory monitoring was performed at the end of baseline and after 8 weeks of blinded medication.There was no significant change in BD at the visit or on ambulatory monitoring in the placebo treated patients. In contrast, nicardipine produced a significant reduction in both blood pressures without affecting heart rate. Nicardipine also decreased the mean 24-h blood pressure by 14/10 mm Hg in patients whose clinical hypertension had been confirmed by ambulatory blood pressure monitoring but by only 3/2 mm Hg in ambulant patients who were normotensive on two-drug therapy.One patient experienced an episode of severe symptomatic hypotension while on nicardipine. Otherwise, the numbers and percentages of patients from each group reporting adverse experiences were similar.It is concluded that nicardipine appears to be an effective antihypertensive agent when used as third line therapy with diuretics and angiotensin converting enzyme inhibitors in patients with severe hypertension. In addition, since 40% of such patients already on two drug therapy were found to have a normal ambulatory blood pressure, the results reinforce the value of ambulatory monitoring in distinguishing hypertensives in whom more aggressive treatment may not by justified.     

24 h blood pressure control with the once daily calcium antagonist, amlodipine.

1. Amlodipine is a novel calcium antagonist which, although pharmacologically similar to other dihydropyridine calcium antagonists, has a long plasma half-life, permitting steady state blood levels to be achieved with a once-daily dose regimen. 2. We have performed a study to examine the effects of this drug on the blood pressure of hypertensive patients over a 24 h period. After a placebo run-in, the drug was administered to 11 patients at a starting dose of 5 mg, and increased to 10 mg after 2 weeks of treatment if the cuff diastolic blood pressure response was unsatisfactory. Cuff measurements were made at entry, after 2 weeks treatment with placebo, after 2 weeks on amlodipine 5 mg once daily, and after a further 4 weeks on amlodipine 5 mg or 10 mg once daily. Intraarterial blood pressure recordings were made at the end of the placebo phase and at completion of the study. 3. Mean supine blood pressure measured sphygmomanometrically was 168/103 (n = 11) mm Hg at entry, 169/104 (n = 11) mm Hg at the end of the placebo phase, 153/95 (n = 11) mm Hg after 2 weeks of treatment and 146/92 (n = 11) mm Hg at the end of the study. Blood pressure curves plotted for each phase of the study revealed an effective 24 h duration of action. Mean daytime blood pressure was reduced from 165/103 to 147/89 mm Hg (P less than 0.05, n = 10), and mean night-time blood pressure was reduced from 137/79 to 121/69 mm Hg (P less than 0.05, n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of enalapril and metoprolol as initial therapy for mild to moderate hypertension

The safety and efficacy of step-one therapy with enalapril, a new angiotensin-converting enzyme inhibitor, and metoprolol were compared in a double-blind, multicenter study involving 150 patients who had mild to moderate essential hypertension. After a four-week period of placebo run-in, therapy was initiated with twice-daily administration of either 5 mg of enalapril (N = 75) or 50 mg of metoprolol (N = 75). Patients who did not achieve a supine diastolic blood pressure of less than 90 mm Hg after six weeks of enalapril (maximum dose = 40 mg/d) or metoprolol (maximum dose = 400 mg/d) had hydrochlorothiazide 50 mg/d added to their treatment regimen for an additional six weeks. Both treatments produced significant (P less than .001) mean reductions in supine and standing blood pressures after 2, 4, 6, 8, 10, and 12 weeks of active therapy. Maximum reductions from baseline values of supine blood pressure in enalapril-treated (-25/-16 mm Hg) and metoprolol-treated (-21/-15 mm Hg) patients were observed after 12 weeks of single- or double-drug therapy. Approximately two-thirds of the patients responded to single-drug therapy; when hydrochlorothiazide was added, response rates increased to 88% of the patients treated with enalapril and 80% of the patients treated with metoprolol. Enalapril produced a consistently greater reduction in systolic blood pressure. Blacks had a significantly smaller mean blood pressure response to both enalapril and metoprolol than did nonblacks. Metoprolol patients had significant mean pulse rate reductions; enalapril patients had no significant change. Four enalapril-treated and six metoprolol-treated patients discontinued treatment because of side effects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Demographic factors and the antihypertensive effect of diltiazem.

The maximum blood pressure (BP) decrease obtained after dose titration with calcium antagonists is said to be greater in older patients. Because the dose necessary to achieve this maximum effect may also vary, it is not clear whether the sensitivity to treatment is actually increased in older patients. We evaluated the possible influence of pretreatment BP, age, and weight on the BP and heart rate (HR) response to 14-day treatment with a fixed dose of 120 mg diltiazem twice daily (b.i.d.) in 231 hypertensive patients aged 24-82 years (44 +/- 27). Diltiazem decreased BP from 171 +/- 1/103 +/- 7 to 156 +/- 1/91 +/- 1 mm Hg. Decreases in both systolic and diastolic BP (SBP, DBP) were related to their pretreatment values (p less than 0.0001 for both). Although pretreatment SBP was related to age (p less than 0.0001), its decrease with diltiazem was not. Neither pretreatment DBP nor its decrease with diltiazem was related to age; BP decrease was not superior in elderly patients (aged greater than 60 years) as compared with that in younger patients (SBP -16 +/- 2 vs. -15 +/- 1 mm Hg, NS; DBP -13 +/- 1 vs. -12 +/- 1 mm Hg, NS). In conclusion, the response to this average dose of diltiazem is related to pretreatment BP and is not affected by patient's age. Because this result is at variance with the concept that calcium antagonists are more effective in the elderly, this concept should not be used as a general therapeutic guideline.     

Felodipine vs hydralazine: a controlled trial as third line therapy in hypertension. Cooperative Study Group.

In a placebo-controlled, double-blind, randomized, parallel group study one hundred and one patients with supine diastolic blood pressure greater than or equal to 100 mm Hg phase V, despite treatment with atenolol 100 mg plus chlorthalidone 25 mg once daily also received either felodipine 5-20 mg twice daily or hydralazine 25-100 mg twice daily for 6 weeks. Felodipine achieved a lower supine blood pressure (mean +/- s.d. 177/108 +/- 29/8-138/82 +/- 19/8 mm Hg) than hydralazine (174/109 +/- 25/8-149/92 +/- 26/11 mm Hg), (P less than 0.05/P less than 0.001). Felodipine also lowered supine diastolic blood pressure to less than 90 mm Hg more often than hydralazine (42 vs 22 patients, P less than 0.001). The incidence of unwanted effects was similar in both groups. The felodipine treated patients experienced more ankle swelling and flushing than those in the hydralazine group who experienced more headache and minor gastro-intestinal upset.     

Assessment of ‘once daily’ verapamil for the treatment of hypertension using ambulatory,intra-arterial blood pressure recording

Summary A new, slow release formulation of verapamil, “verapamil o.d.” was administered to 12 patients with essential hypertension. Drug administration was started at a dose of 240 mg and increased to 480 mg after 2 weeks of treatment if the cuff blood pressure response was unsatisfactory. The drug reduced the daytime intra-arterial blood pressure significantly from 180.7/106.8 mm Hg to 157.3/89.4 mm Hg. The daytime heart rate fell from 88.1 to 71.8 beats/min. The nighttime blood pressure decreased from 155.7/87.2 mm Hg to 140.5/75.3 mm Hg. The nocturnal heart rate decreased from 62.8 to 57 beats/min. Hourly plots of mean systolic and diastolic pressure showed a significant reduction of systolic pressure for 21 of 24 h and of diastolic pressure for all 24 h following a single morning dose. The drug modified the absolute blood pressure and heart-rate response during both forms of exercise, but did not alter the magnitude or rate of blood pressure change. The tilt-test produced no evidence of postural hypotension. Only one patient experienced any side effects whilst taking the drug. These results indicate good 24-h blood pressure control and reduced exercise blood pressure levels during treatment with this new formulation of verapamil. The reduced frequency of drug administration should improve patient complicance with treatment of hypertension.     

24-hour blood pressure control with the once-daily calcium antagonist amlodipine

The efficacy and toleration of once-daily amlodipine (5-10 mg) was studied in 11 patients with mild to moderate hypertension. Continuous intra-arterial blood pressure monitoring was used to study the effects of amlodipine over a 24-h period. Following a 2-week placebo run-in period, amlodipine was given initially as a single-blind 5-mg dose for 2 weeks and increased to 10 mg if required to control blood pressure for a further 4 weeks. Twenty-four-hour intra-arterial blood pressure recordings made after 6 weeks of treatment with amlodipine revealed that amlodipine effectively reduced blood pressure throughout the whole 24-h period without altering the normal circadian pattern. The mean daytime blood pressure was reduced from 165/103 to 147/89 mm Hg (p < 0.05) and the mean nighttime blood pressure was reduced from 137/79 to 121/69 mm Hg (p < 0.05). There was no significant change in heart rate. The mean supine blood pressure measured sphygmomanometrically was reduced from 169/103 mm Hg after placebo to 153/98 mm Hg after 2 weeks of treatment and to 145/92 mm Hg at the end of the study. The results of isometric and dynamic exercise testing showed that amlodipine decreased blood pressure, with no postural decrease on tilting and no change in the proportional increase in blood pressure at peak exercise. Amlodipine was well tolerated although one patient developed ankle edema that would have required discontinuation had she not already completed the study. This study has shown that amlodipine effectively reduced blood pressure for 24 h after once-daily dosing and was well tolerated.     

24-hour control of blood pressure by once daily doxazosin: a multicentre double-blind comparison with placebo

Summary The antihypertensive efficacy of the new, once daily, alpha₁-adrenoceptor inhibitor, doxazosin, was compared with placebo in 40 patients with mild to moderate hypertension. Following a dose titration the mean final daily doxazosin dose in 20 patients was 13.1 mg.Through-the-day blood pressure control was assessed by frequent measurements during 24 h hospitalisation in the 9 th week of double-blind treatment compared with similar measurements made during a 2 week single-blind placebo run-in.Mean reductions in standing and supine systolic and diastolic blood pressure during doxazosin treatment were statistically significantly greater than during placebo treatment at most hourly time points during the 24 h post-dose period. Twenty-four post-dose the mean falls in standing and supine diastolic blood pressure during doxazosin treatment were statistically significant when compared with placebo. Adverse effects during doxazosin treatment were generally minor and were tolerated or disappeared with continued therapy. No patients were withdrawn from the study due to adverse effects.We conclude that once daily doxazosin provides smooth and effective blood pressure control throughout a 24 h post-dose period.     

Efficacy and tolerability of isradipine and metoprolol in treatment of hypertension: the Finnish Isradipine Study in Hypertension (FISH).

Eight hundred seventy-six men and women with diastolic blood pressure (DBP) of 95-115 mm Hg during a 4-week placebo period were included in a multicenter trial; 479 patients had previously been treated for hypertension. The patients were randomized to receive isradipine or metoprolol; both groups were comparable for age, weight, height, smoking habits, and duration of hypertension. By the end of the placebo period, 79 patients did not fulfill the final entry criteria and were withdrawn. The isradipine group consisted of 398 patients (164 women and 234 men), and the metoprolol group consisted of 399 patients (173 women and 226 men). The initial dose of isradipine was 1.25 mg twice daily (b.i.d.), and the initial dose of metoprolol was 50 mg b.i.d.; the doses were doubled after 4 weeks if DBP had not decreased to less than or equal to 90 mm Hg. After 8 weeks, the isradipine group began combination therapy with metoprolol 50 mg b.i.d. and the metoprolol group began combination therapy with isradipine 1.25 mg b.i.d. if DBP was not less than or equal to 90 mm Hg. After 8 weeks monotherapy, mean BP (MBP) was reduced by 13/11 mm Hg (161/104 to 148/93) in the isradipine group and by 15/12 mm Hg (160/103 to 145/91) in the metoprolol group. Monotherapy with isradipine normalized DBP to less than or equal to 90 mm Hg in 52% with a mean dose of 4.26 mg daily, and monotherapy with metoprolol normalized DBP in 58% with a mean dose of 155 mg daily.1+     

Felodipine extended release in mild to moderate hypertension

A multi-centre study was carried out to examine the antihypertensive effect and adverse event profile of felodipine in an extended-release (ER) formulation given once daily as monotherapy. Doses of 5 mg, 10 mg or 20 mg felodipine ER were compared with placebo in 183 patients with mild or moderate hypertension. All antihypertensive medication was discontinued on entering a 4-week placebo run-in period. If, at the end of the run-in period, supine diastolic blood pressure was in the range greater than 95 less than 120 mmHg, patients were randomly allocated to double-blind treatment with felodipine, 5 mg, 10 mg or 20 mg, or placebo, to be taken once daily for 4 weeks. Supine and standing blood pressure, heart rate and body weight were measured every 2 weeks during the trial. Assessments were made 24 hours after intake of the study drug. Adverse events were recorded at each review. Over the 4-week treatment period, a dose-related decrease in supine diastolic blood pressure was observed, this reduction occurring already during the first 2 weeks of active treatment. In the placebo group and the felodipine 5 mg, 10 mg and 20 mg groups, supine blood pressure (systolic/diastolic) decreased by 7/6 mmHg, 9/8 mmHg, 12/10 mmHg and 14/11 mmHg, respectively. Supine diastolic blood pressure reduction in the felodipine 10 mg group and both systolic and diastolic blood pressure reductions in the 20 mg group were significantly greater than with placebo. Standing diastolic blood pressure reduction was significantly greater in all three dose groups on felodipine compared with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)