Failure of the antioxidant vitamin E to protect against adriamycin-induced cardiotoxicity in the rabbit.

Recently, vitamin E has been proposed to protect against Adriamycin-induced cardiotoxicity. We studied contractile decline and ultramicroscopic alterations of the heart of rabbits chronically treated with Adriamycin up to a cumulative dose of 400 mg/sq m. High doses of vitamin E did not protect against the Adriamycin-induced development of severe contractile decline as evaluated by means of measurement of the interval-force relationship curve. Light and electron microscopic analysis did not show any signs of protection against Adriamycin-induced morphological alterations. Biochemical and hematological alterations. Biochemical and hematological alterations caused by the antineoplastic agent were similar in both Adriamycin-treated animal groups. Coadministration of vitamin E did result in an increased life span. This study indicates that vitamin E does not protect against the development of cardiomyopathy and contractile decline after chronic exposure to Adriamycin.

The influence of perindopril and the diuretic combination amiloride+hydrochlorothiazide on the vessel wall properties of large arteries in hypertensive patients.

OBJECTIVE: To compare the cardiovascular effects of 6 months of treatment with the angiotensin converting enzyme inhibitor perindopril and with the diuretic combination amiloride+hydrochlorothiazide, and to study possible persistence of observed treatment effects after discontinuation of antihypertensive therapy. DESIGN: A placebo run-in period preceded a 6-month active-treatment phase in 41 patients with essential hypertension, according to a double-blind, randomized, parallel-group design. Patients received either 4 mg perindopril or 2.5/25 mg amiloride+hydrochlorothiazide once a day. Patients were then studied for a 3-month single-blind placebo run-out period. RESULTS: After 6 months of treatment, systolic blood pressure was reduced significantly by perindopril (supine by 11%, sitting by 10%) and by amiloride+hydrochlorothiazide (supine by 8%, sitting by 12%). Diastolic blood pressure was also decreased significantly by perindopril (supine by 8%, sitting by 11%) and by amiloride+hydrochlorothiazide (supine by 4%, sitting by 9%). Mean arterial pressure decreased significantly during treatment with perindopril (by 9%) and with amiloride+hydrochlorothiazide (by 6%). Cardiac index increased with perindopril (by 6%), because of an increased stroke index (by 5%), but amiloride+hydrochlorothiazide did not change cardiac function. Systemic vascular resistance index decreased significantly more with perindopril (by 14%) than with amiloride+hydrochlorothiazide (by 8%). The distensibility of the common carotid artery was significantly enhanced by perindopril (by 16%), but not changed by amiloride+hydrochlorothiazide (1% difference). The difference between perindopril and amiloride+hydrochlorothiazide for carotid distensibility was statistically significant. The compliance of the common carotid artery tended to be increased more by perindopril (by 7%) than by amiloride+hydrochlorothiazide, which induced a 5% decrease in carotid compliance. After withdrawal of therapy, for both drugs, all treatment-induced changes were reversed to pretreatment values within 7 weeks. CONCLUSION: The distensibility of the elastic common carotid artery was increased by perindopril, but not by amiloride+hydrochlorothiazide. Large-artery properties of the muscular arteries and systemic vascular resistance improved with both drugs, but in general the changes were more pronounced with perindopril than with amiloride+hydrochlorothiazide. The present results indicate a more pronounced effect of perindopril at both macro- and microcirculatory levels, which will consequently lead to a larger decrease in cardiac afterload. After discontinuation of therapy all parameters returned to baseline values within 7 weeks.

A randomized trial in primary biliary cirrhosis comparing ursodeoxycholic acid in daily doses of either 10 mg/kg or 20 mg/kg. Dutch Multicentre PBC Study Group.

BACKGROUND: Ursodeoxycholic acid (UDCA) prolongs transplantation-free survival in primary biliary cirrhosis (PBC). However, the optimal therapeutic dose has not been established. AIM: To compare the effects of UDCA administered in daily doses of 10 vs. 20 mg/kg on symptoms, liver biochemistry and biliary UDCA enrichment. METHODS: A 6-month multicentre randomized open controlled trial was conducted to assess the effects of an increase in the dose of UDCA to 20 mg/kg/day vs. continuation of 10 mg/kg/day for patients who had not achieved biochemical normalization during treatment for at least 6 months with the 10 mg/kg dose. Clinical and laboratory evaluations were performed at entry and at 3-month intervals. The percentage UDCA in duodenal bile was assessed at entry and at 6 months. RESULTS: Sixty-one patients were enrolled. No side-effects of UDCA were observed. Within the 20 mg/kg/day group significant decreases were found for alkaline phosphatase (- 8%; P = 0.003), aspartate aminotransferase (- 11%; P = 0.01), alanine aminotransferase (- 17%; P < 0.001), gamma-glutamyl transferase (- 34%; P < 0.001), immunoglobulin M (- 11%; P = 0.002) and cholesterol (- 8.1%; P < 0.001). In the 10 mg/kg group none of these parameters differed significantly from baseline. No significant differences between dose groups for symptom scores or serum bilirubin were found. Biliary enrichment with UDCA increased from 37% to 46% in the 20 mg/kg group (P = 0.02) while remaining stable in the 10 mg/kg group. CONCLUSIONS: Liver biochemistry improved in PBC patients receiving UDCA 20 mg/kg/day compared to a dose of 10 mg/kg/day. Both doses were equally well tolerated. These results indicate that UDCA 10 mg/kg/ day is a suboptimal dose for treating PBC.

Treatment of elderly patients with isolated systolic hypertension with isosorbide dinitrate in an asymmetric dosing schedule.

Nitrates decrease pulse pressure more than mean arterial pressure (MAP) and are advocated for the treatment of isolated systolic hypertension (ISH). Nitrates show drug tolerance during chronic treatment so an asymmetric dosing regimen may prevent loss of effect of nitrates. This study investigates the anti-hypertensive effect of isosorbide dinitrate (ISDN) given in a twice daily asymmetric dosing regimen in elderly patients with ISH. After a 6-week placebo run-in period, patients entered the double-blind study. Ten patients received placebo and 11 patients ISDN 20 mg b.i.d. for 8 weeks. This dose could be doubled once. Office systolic and diastolic blood pressures (SBP/DBP) and ambulatory BP were measured. Pulse pressure was calculated as SBP-DBP. Office pulse pressure was more reduced during ISDN (17.9%) than with placebo (5%; P < 0.05). SBP and MAP decreased compared to baseline, but the changes were not statistically significant between the two groups. DBP tended to increase with ISDN compared to placebo. Mean 24-h, mean daytime and mean night-time pulse pressure decreased after treatment with ISDN (10.7%, 12.1%, 7.9%, respectively). Pulse pressure tended to decrease more during the day than during the night with ISDN. No changes could be demonstrated with placebo. In conclusion, pulse pressure decreased with ISDN, resulting in a lower SBP without a decrease in DBP. The latter may preserve coronary perfusion in ISH. With the asymmetric dosing regimen the decrease in pulse pressure was not clear at night. Whether a decrease in nocturnal BP, in addition to the spontaneous decrease, is advisable in ISH remains a matter of debate.

Calcium antagonists, a useful additional therapy in treatment resistant hypertension: comparison of felodipine ER and nifedipine Retard by 24-h ambulatory blood pressure monitoring.

OBJECTIVE: To compare the efficacy and tolerability of felodipine extended release (ER) 2.5 mg (F2.5) and 5 mg (F5) once daily with nifedipine Retard 10 mg (N20) and 20 mg (N40) twice daily as additional therapy in patients who remained hypertensive despite treatment with an ACE-inhibitor, beta-blocker or diuretic. DESIGN AND METHODS: In a multicentre, double-blind parallel study, 61 men and 54 women, aged 35-75, with a supine diastolic blood pressure between 95 and 115 mmHg were randomised to treatment with F2.5, F5, N20 or N40 for 8 weeks, with optional doubling of the dose after 4 weeks. Blood pressure was measured at the office after 0, 4 and 8 weeks and by 24-h ambulatory monitoring (ABPM) after 0 and 4 weeks. Spontaneously reported adverse events and a subjective symptom assessment questionnaire were used for side-effect profiling. RESULTS: Mean office systolic/diastolic blood pressure was clinically relevantly reduced in all treatment groups after 4 weeks by 8/7, 12/9, 11/9 and 18/11 mmHg for F2.5, F5, N20 and N40, respectively, and after 8 weeks (F2.5-5: 17/11 mmHg: F5-10: 18/14 mmHg; N20-40: 19/14 mmHg; N40-80: 25/14 mmHg) with no statistically significant differences between these groups. The lowest dose of felodipine (F2.5) was the least effective. After 4 weeks the ABPM showed consistent 24-h reductions in blood pressure (4/2; 8/5; 7/5; 10/6 mmHg, respectively) over 24 h for the felodipine ER 5 mg group only and for both nifedipine groups. No statistically significant difference between these groups was found. An office responder does not appear to be identical to an ambulatory one and vice versa. The adverse events, mostly oedema, flushing and headache, were dose-related. CONCLUSIONS: Both felodipine ER and nifedipine Retard are effective "add-on' drugs in patients with monotherapy-resistant hypertension. The blood-pressure-lowering effect is dose-dependent and tolerability is inversely related to efficacy. The results emphasize the benefits of combining two agents with low doses.

The interval-force relationship: a technique for evaluating the cardiac toxicity of anthracycline analogs.

The most serious side effect of the anthracycline derivatives is dose-related cardiac toxicity induced during repeated administration. An in vitro method is described which assesses the interval-force relationship in evaluating the contractility of the rat and rabbit heart. Repeated administration of Adriamycin resulted in a progressive decrease in contractility which correlated closely with the cumulative dose administered. This model offers a reliable method to evaluate the effect of new anthracycline analogs on the heart and to study the potential of other drugs or agents to protect against cardiac toxicity.

Quality of life perception during antihypertensive treatment: a comparative study of bisoprolol and enalapril.

The well-being of hypertensive patients may be adversely affected by the disease itself, its complications, and other concomitant processes such as anxiety, sedation, and side effects of prescribed drugs. Some recently developed antihypertensive agents have been suggested to be devoid of these deleterious effects on well-being expressed as quality of life. We compared the effect on quality of life of the angiotensin-converting enzyme (ACE) inhibitor enalapril to the effect of bisoprolol as a representative of a new class of selective beta 1-adrenoreceptor blocking agents. Fifty-seven patients with mild to moderate hypertension were eligible to enter an 18-week cross-over study, consisting of a single-blind 2-week run-in period and two 8-week double-blind cross-over periods. At the end of the run-in period and the two cross-over periods, both systolic and diastolic blood pressure (SBP, DBP) were assessed, as was quality of life perception by the Inventory of Subjective Health. During bisoprolol treatment, supine BP decreased from 163 +/- 2/102 +/- 1 to 144 +/- 3/86 +/- 1 mm Hg. The antihypertensive effect was at least as good with bisoprolol as with enalapril. Quality of life perception as measured with the Inventory of Subjective Health was comparable for the two drugs. Spontaneously mentioned adverse effects were more frequent (74%) during enalapril than during bisoprolol treatment. At the end of the study, 69% of patients chose to continue antihypertensive treatment with bisoprolol. Our results show that the highly selective beta 1-adrenoreceptor blocking drug bisoprolol is at least as effective as enalapril and has no deleterious effects on well-being.

Nebivolol in hypertension: a double-blind placebo-controlled multicenter study assessing its antihypertensive efficacy and impact on quality of life.

Nebivolol is a selective beta 1-adrenoceptor antagonist with a particular hemodynamic profile, suggesting an ancillary vasodilating property. The nature of this ancillary property is still unknown. The present double-blind placebo-controlled multicenter study investigated the effect of 4 and 8 weeks treatment with nebivolol 5 mg once daily on blood pressure (BP), heart rate (HR), blood parameters, and ECG. The effect on quality of life perception and the adverse effect profile were also studied. Nebivolol 5 mg once daily had a good antihypertensive effect in supine (10/8 mm Hg) as well as in standing position (16/10 mm Hg). Of 114 patients studied, 65% had either normalization of or > 10% reduction in diastolic BP (DBP). No evidence of drug tolerance was observed during the 8-week treatment period. Quality of life perception, as measured with the Inventory of Subjective Health (ISH) and the perceived health rating scale, was not impaired with nebivolol during the entire 8-week study. Nebivolol showed a favorable adverse effect profile and appeared to be devoid of central nervous system (CNS) adverse effects. The total number of complaints with nebivolol treatment did not differ from the number of complaints with placebo treatment. ECG and blood analyses, also show that nebivolol is safe and well tolerated. This study also shows that absolute drug-induced changes in quality of life perception can be assessed only in a placebo-controlled study and that comparison with baseline might be incorrect and misleading.