Platelet 3H-imipramine binding and response to minaprine in patients with major depression

Platelet 3H-imipramine binding was studied in 37 patients fulfilling Research Diagnostic Criteria for major depressive disorder, examined before and after four weeks of treatment with minaprine 200 mg/day, and in 19 healthy controls. Mean baseline Bmax values of depressed patients were found to be significantly lower than those of controls, while no significant difference between the two groups was observed with respect to mean Kd. Treatment with minaprine did not significantly affect Bmax or Kd in depressed patients. When patients who responded to treatment (n = 18) were compared with nonresponders (n = 19), mean baseline Bmax values were found to be significantly lower in the former group, whereas mean Kd values did not differ. It is hypothesized that reduced 3H-imipramine binding may represent a predictor of a favorable response to antidepressant drugs which potentiate serotonergic transmission.

[Efficacy and tolerability of a delayed-action vasodilator agent, cadralazine, in severe chronic cardiac failure]

The aim of this work is the evaluation of the hemodynamic effects during the 24 hours following a single administration of a new arterial vasodilator, cadralazine, in 12 patients whose mean age is 66 years and who present severe cardiac insufficiency. A clinical and hemodynamic examination was made before administration of the medicine in 3 doses at 12 hour intervals in order to check the stationary state of the patients, and then at 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 20 h and 24 h after 30 mg, and then 60 mg of cadralazine. We did not observe any significant change in cardiac frequency, nor in the systolic arterial pressure nor in the diastolic arterial pressure of the pulmonary artery, after either 30 mg or 60 mg. On the other hand, with 30 mg of cadralazine we observed a significant increase of the cardiac index, with a maximum between the 6th and 8th hour (1.58 +/- 0.51 l.min-1.m-2 before treatment to 2.66 +/- 0,75 l.min-1.m-2 8 hours after, p less than 0.001) and a fall of total systemic resistance which declined from 2,478 +/- 421 dyn.s-1.cm-5 before treatment to 1,449 +/- 369 dyn.s-1.cm-5, p less than 0.001, 8 hours after, as well as an increase in the power of the left ventricule (from 2.80 +/- 0.8 before treatment to 4.73 +/- 1.2 kg/min 8 hours after, p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cadralazine and chlorthalidone as a second-step drug with atenolol in hypertensive patients: differences in blood pressure control during exercise

The long-term efficacy of a new vasodilator, cadralazine (ISF 2469), and chlorthalidone have been compared in 20 hypertensive patients not adequately controlled by atenolol. After 4 weeks of treatment with atenolol 100 mg once daily, patients whose diastolic blood pressure was greater than 95 mmHg were randomly divided into two groups to receive in addition to atenolol, either cadralazine 15 mg once daily or chlorthalidone 25 mg once daily. Both treatments were administered for 6 months. At the end of treatment with atenolol and after 3 and 6 months of combination therapy, blood pressure and heart rate were measured at rest and during bicycle exercise 24 h after the last dose. Compared to atenolol alone, both cadralazine and chlorthalidone caused a significant and similar reduction in resting blood pressure. Both groups showed an increase in diastolic blood pressure during exercise while receiving atenolol alone. The addition of chlorthalidone did not modify the pressor response to exercise, whereas patients taking cadralazine had a decrease in exercise diastolic blood pressure, which was fully evident after 6 months of therapy. The reduction in exercise diastolic blood pressure induced by cadralazine was proportional to the increase in exercise heart rate, suggesting a fall in peripheral vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of once daily endralazine in hypertension

Endralazine, a novel vasodilator related to hydralazine, exhibits a longer half-life and is only minimally influenced by acetylator status. The antihypertensive action of once daily endralazine has been studied in 17 patients previously controlled with an antihypertensive regimen which included hydralazine and a beta-blocker. Hydralazine was discontinued but other medications were unchanged. Pre-study dosage of hydralazine ranged from 25 mg b.i.d. to 50 mg g.i.d., mean daily dose 126.5 mg. Endralazine was started at a dose of 10 mg o.d. and increased by 10 mg to a maximum of 40 mg o.d. until seated DBP was controlled below 95 mmHg. All 17 patients completed the study. Seated BP significantly decreased from 147.5/99.7 to 133.8/83.9 and standing BP from 145.8/99.2 to 133.6/87.3 mmHg. Ten patients (59%) were successfully controlled with endralazine once daily but 7 patients required twice daily dosage schedules because of lack of BP control at 24 h after dosing or excessive hypotension shortly after dosing. Other adverse effects were headache, palpitations and fatigue. There was a statistically insignificant average weight gain of 1 kg but pedal edema was not observed. Endralazine is an effective antihypertensive agent with adverse symptoms similar to those experienced with hydralazine.

Comparative study of endralazine and hydralazine for the treatment of hypertension uncontrolled by a beta-blocker and diuretic

Endralazine and hydralazine were compared in a randomized double-blind, parallel group study lasting 1 year in 30 patients with essential hypertension inadequately controlled by a beta-blocker and a diuretic. Dosage ranged from 10 mg to 30 mg endralazine per day and from 75 mg to 200 mg hydralazine per day according to patient response. The results showed that endralazine was at least as effective as hydralazine in reducing blood pressure. Patients' tolerance, assessed by drop-out rate, was significantly better (p less than 0.05) in the endralazine group. No cases were found of drug-induced lupus-like syndrome on endralazine as opposed to 2 cases with hydralazine. The dose of endralazine required much less adjustment than that of hydralazine.

Behavioral effects of microinjections of SR 95103, a new GABA-A antagonist, into the medial hypothalamus or the mesencephalic central gray

The behavioral effects of unilateral microinjections of SR 95103, a new GABA-A receptor antagonist, into periventricular structures were studied. When injected into the medial hypothalamus (MH) or into the dorsal part of the mesencephalic central gray (CG), SR 95103 produced a dose-dependent behavioral activation together with jumps. However, the characteristics of this behavioral activation differed according to whether SR 95103 was injected into the MH or into the CG. The behavioral activation was found to be attenuated by pretreatment with THIP, a GABA receptor agonist. When injected into the CG or into the deep layers of the superior colliculus, SR 95103 proved to affect the rat's reactivity to tactile stimuli as evidenced by ipsilateral 'neglect' combined with contralateral hyperreactivity expressed as withdrawal reactions and jumping. Similar results were obtained following microinjections of bicuculline methiodide at the same sites. These data confirm that in both the MH and the CG, GABA-A receptors are involved in the neural control of the generation and/or expression of aversive effects. The data further suggest that at the level of the CG and the deep layers of the superior colliculus, GABA is also involved in the gating of sensory information towards the substrate underlying the generation of such aversive effects.

Antihypertensive activity of a new vasodilator, cadralazine, administered alone or in combination with a beta-blocker

The antihypertensive activity of a new arterial dilator, cadralazine, was evaluated in 40 patients with mild-to-moderate arterial hypertension. Cadralazine was given once daily over 6 weeks, and blood pressure and heart rate were recorded 24-26 hours after dosing. Cadralazine dose was 10 mg daily initially, and 15 or 20 mg daily from the 3rd or 5th trial week according to a target diastolic pressure reduction to 95 mmHg or below. Slow-release metoprolol 200 mg once daily was added when heart rate increase exceeded 25% of the pretreatment value. Blood pressure showed a significant and progressive reduction throughout the study period, both in the patients receiving cadralazine as monotherapy (19 patients) and in those who added metoprolol (21 patients). The target diastolic pressure reduction was reached in 2 patients with the 10-mg dose, in 19 of the remaining 38 patients with the 15-mg dose, and in 13 of the other 19 patients with the 20-mg dose. Considering only those patients who did not add metoprolol, the target was reached in the 2 patients with the 10-mg dose, in 10 of the 19 patients with the 15-mg dose and in 7 of the 19 patients with the 20-mg dose. None of the laboratory tests showed clinically relevant changes. Neither LE cells nor antinuclear antibodies were found. In conclusion, cadralazine is a promising long-acting antihypertensive vasodilator. A clinically satisfactory antihypertensive effect is achieved mostly by a 15-mg or a 20-mg dose given once daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in blood pressure, fluid volumes and glomerular filtration rate during long-term treatment with prizidilol, an antihypertensive drug with combined vasodilatator and beta-adrenoceptor blocking actions

The long term effects on blood pressure, body fluid volumes, glomerular filtration rate and plasma renin concentration were studied in 11 patients with essential hypertension during treatment with prizidilol, which is an antihypertensive compound with combined vasodilatator and beta-adrenoceptor blocking actions. After the patients had been treated for four weeks with placebo, the active treatment was given for 12 weeks. Prizidilol reduced both supine and erect blood pressure by 26/14 mmHg (p less than 0.01) and 24/16 mmHg (p less than 0.01) respectively, without inducing significant changes in heart rate. Plasma volume increased significantly by eight percent (p less than 0.02), whereas the increase in extracellular fluid volume was insignificant. Glomerular filtration rate decreased by 4 ml/min./1.73 m2 (p less than 0.02). Plasma renin concentration was unchanged. Prizidilol was tolerated well, but six patients developed oedema and gained weight, which necessitated addition of diuretics in three patients.

[Antihypertensive pharmacotherapy with the vasodilators captopril and endralazine]

A comparative, controlled, open hypertension study using the direct vasodilator endralazine and the ACE-inhibitor captopril in combined therapy for severe and moderately severe hypertension is described. Both vasodilators cause an approximately 20% reduction in supine and upright blood pressure. Extreme side effects such as hematological alterations, autoimmune states or uncontrollable water retention were not observed. Subjective symptoms, particularly severe headaches, were especially evident after endralazine use. This side effect may possibly be eliminated by gradual titration over several weeks.

Controlled clinical trial of cadralazine as a second-step drug in the treatment of hypertension

The antihypertensive efficacy of a new long-lasting vasodilator, cadralazine, and the diuretic chlorthalidone have been compared in hypertensive patients receiving concurrent treatment with atenolol. After a 4-week run-in period with atenolol alone 100 mg/day, two groups of 10 patients whose diastolic blood pressure exceeded 100 mm Hg were given for a period of 65 days either cadralazine 15 mg/day or chlorthalidone 25 mg/day, according to a randomized, double-blind, between-patients design. Compared to atenolol alone, both cadralazine and chlorthalidone induced a statistically and clinically significant decrease in blood pressure. The antihypertensive effect did not differ significantly between groups. Good compensation of the atenolol-induced decrease in heart rate was obtained with cadralazine, whereas during atenolol + chlorthalidone treatment at times the standing heart rate was significantly lower than during treatment with atenolol + cadralazine. Side-effects, many of which were already present during atenolol treatment, occurred with a similar frequency in both groups. It is concluded that atenolol + cadralazine and atenolol + chlorthalidone are equally well tolerated, acceptable and effective in the treatment of hypertension, but that further studies are warranted to explore the potential haemodynamic advantages of the cadralazine + atenolol combination.

Review of adverse reactions associated with cinoxacin and other drugs used to treat urinary tract infections

The evaluation of adverse drug reactions (ADR) in clinical practice is difficult and imprecise. Establishing a causal relationship may not be possible, and data on incidence cannot be obtained because the number of patients treated is not known. This article describes the ADR reported during the clinical trial program of cinoxacin, a synthetic antibacterial drug used to treat urinary tract infections. Results from 2,801 patients who received cinoxacin showed that 5 per cent reported ADR that were probably or definitely drug induced, and 10 per cent reported ADR in which the relationship was uncertain. There was no relationship between number of reports and patient's age, drug dose, or duration of treatment. Adverse drug reactions affecting the gastrointestinal system were reported by 5.5 per cent of the patients, those involving the central nervous system by 4.3 per cent, and hypersensitivity reported by 2.4 per cent. In the comparative studies, patients treated with cinoxacin reported fewer ADR than those treated with nalidixic acid, furadantin, amoxicillin, or trimethoprim-sulfamethoxazole. Although problems in the assessment and evaluation of ADR still exist, it is hoped that the results from the formal trial program will be representative of those seen in clinical practice.

Comparison of the antihypertensive activity of cadralazine (ISF 2469) and dihydralazine during chronic treatment

The antihypertensive activity of a new vasodilating agent (ISF 2469) cadralazine (CD) was compared in a randomized, crossover, intrapatient study with that of hydralazine (HD) in 20 hypertensive patients whose diastolic blood pressure (BP) was greater than 95 mmHg during treatment with atenolol (AT), 100 mg 1 X daily. The initial dose of CD was 15 mg 1 X daily; after 15 days in case of poor response, the dose was increased to 20 mg 1 X daily. HD was given at a dose of 25 mg 3 X daily and was increased to 50 mg 2 X daily in case of poor response. BP values (standing) during AT were 174/108; they fell to 144/88 during CD and to 138/88 during HD. No significant difference was detected between the two drugs for both systolic and diastolic BP (supine and standing). Heart rate increased with both drugs, with a greater increase during CD. The difference was clinically nonsignificant. A total of 24 patients were enrolled, but 4 had to cease treatment because of side effects during HD. The overall prevalence of side effects was much higher during HD, especially during the first days of therapy. Also the severity of side effects was greater during HD. Our data show that CD has the same antihypertensive activity as HD with a lesser incidence of side effects and with a single dose/day administration in contrast with three administrations of HD. This can result in greater patient compliance.

Prizidilol, a combined vasodilatory and beta-adrenoceptor blocking drug, in primary hypertension. A long-term efficacy, tolerance and pharmacokinetic study

After an initial placebo period of four weeks 24 patients with primary hypertension were treated with prizidilol, a hydrazinopyridazine derivative with combined vasodilator and non-selective beta-adrenoceptor blocking actions, for a dose titration period of 14 weeks. Prizidilol 200 to 800 mg was given once daily to achieve a target supine diastolic blood pressure (BP) less than 90 mmHg. Supine and standing BP recorded 24-27 h after drug intake decreased from 172 +/- 17/106 +/- 6 mmHg (mean +/- SD) and 167 +/- 18/111 +/- 8 mmHg, respectively, after placebo to 159 +/- 16/99 +/- 8 and 154 +/- 18/101 +/- 9 mmHg after active treatment for six weeks (mean dose 447 mg), and to 154 +/- 16/97 +/- 7 and 148 +/- 14/97 +/- 7 mmHg after treatment for 14 weeks (mean dose 687 mg/day). A slight reduction in HR was seen after treatment for six weeks and in plasma renin activity and urinary methoxycatecholamine excretion after treatment for 14 weeks. A sustained decrease in BP was observed for 10 h after prizidilol 800 mg (n = 9), with a maximum antihypertensive effect (mean reduction in supine BP 33/18 mmHg) 2.5 h after dosing, which coincided with the mean peak plasma concentration. The plasma elimination half-life of the drug was 3.9 h (range 2.0-8.9 h). Changing to a twice daily regimen in 17 patients (mean daily dose 748 mg at six months) did not produce any further reduction in the BP (recorded 12-15 h after dosing) as compared to the once daily regimen at 14 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacodynamic studies in normal volunteers with MDL-899, a new arteriolar vasodilator

We conducted pharmacodynamic studies with a new vasodilator, MDL-899. Following initial dose-ranging studies we studied eight male normotensive volunteers, each of whom received, orally, 10 mg MDL-899 or placebo in double-blind random order. MDL-899 significantly lowered standing blood pressure, the maximal effect occurring 3-6 h following drug administration. There was a significant increase in heart rate in both supine and standing positions, maximal 6-8 h postdose. Supine plasma noradrenaline concentrations were greater following MDL-899, with the greatest difference present 4 h after drug administration. Plasma renin concentrations were greater following MDL-899. Six of our subjects were also given 10 mg MDL-899 together with 100 mg atenolol, in an additional study. Atenolol increased the hypotensive effect and attenuated the tachycardia following MDL-899 alone. Side effects following MDL-899 administration included headache, lightheadedness, and tachycardia. These were reduced following atenolol coadministration. The haemodynamic profile of MDL-899 suggests that this drug acts as a direct arteriolar vasodilator in man. The observed increase in heart rate is likely mediated by reflex activation of the sympathetic nervous system.

Effects of intravenous endralazine in essential hypertension

The effects of endralazine, administered intravenously, on blood pressure, heart rate, forearm blood flow, plasma renin activity, aldosterone, adrenaline and noradrenaline were studied in five patients with essential hypertension. Endralazine reduced peripheral vascular resistance, resulting in decrease in mean arterial pressure from 141 to 116 mm Hg and increase in heart rate from 67 to 92 beats/min. Plasma renin activity, adrenaline and noradrenaline increased significantly after endralazine infusion. All effects observed are consistent with endralazine acting as a peripheral vasodilating drug.

A crossover trial of oxdralazine in hypertension

Twenty-nine moderate and severe essential hypertensive patients completed a crossover study aimed at evaluating efficacy and tolerability of a double combination (chlorthalidone plus propranolol) and of a triple combination (chlorthalidone plus oxdralazine plus propranolol). After one month on 25 mg/day chlorthalidone, which caused nonsignificant reduction in blood pressure of 7/4 mm Hg, patients were randomized to receive either the double or triple regimen for a three-month period. Then, after another month on chlorthalidone alone at the same dose of 25 mg/day, treatments were crossed over and the study continued for another three-month period. The double regimen caused a drop in pressure of 16/11 mm Hg after one month (daily doses 25 mg chlorthalidone, 103 +/- 25 mg propranolol), and this reduction did not change at the third month in spite of dosage increases (daily doses 25 mg chlorthalidone, 222 +/- 77 mg propranolol). The triple regimen reduced blood pressure 35/15 mm Hg after one month (daily doses 25 mg chlorthalidone, 20 mg oxdralazine, 40 mg propranolol), and further increase in dosages caused a reduction of 45/24 mm Hg at the third month (daily doses 25 mg chlorthalidone, 56 +/- 20 mg oxdralazine, 112 +/- 40 mg propranolol). Both treatments were well tolerated; in particular, at the end of the third month of each treatment period, 25 patients on the triple regimen achieved a stable diastolic blood pressure of 90 mm Hg or less, as compared to 10 patients on the double regimen (P less than 0.01).

Endralazine, a new peripheral vasodilator. Evaluation of safety and efficacy over a 3 year period

Nineteen out-patients with moderate to severe essential hypertension were treated daily for 3 years, with an average dose of 13 mg endralazine, a new peripheral vasodilator, in free combination with pindolol 3 x 5 mg. The blood pressure showed a statistically significant reduction from 172/110 mmHg to 154/92 mmHg after treatment for 3 years. Tachyphylaxis was not observed during the 3 years period. Oedema was the most frequent side-effect, but it disappeared spontaneously. No difference in efficacy and tolerance between slow and fast acetylators was found. Only 2 patients developed a weak positive antinuclear antibody titre, which disappeared spontaneously from one during continued treatment. No clinical evidence of a systemic lupus erythematosus-like syndrome was noted. It is concluded that the differences between endralazine and hydralazine in dosage and metabolism may explain the lower immunogenic activity of endralazine.

Cadralazine (ISF 2469): dose-related antihypertensive activity after single oral administration to patients

Cadralazine (ISF 2469) was administered to 24 hypertensive patients in single oral doses of 7.5, 10, 15, 20 and 30 mg, according to a single-blind, placebo-controlled, within-patient change-over design. The study was done in 2 stages: in the first a range including the upper and lower doses was studied (7.5, 15, 30 mg and placebo), and in the second the range of doses was restricted (10, 15, 20 mg and placebo). The drug produced a significant decrease in blood pressure in the supine and standing positions. The decrease became clinically important starting from the 15 mg dose. Its action was still significant 12 h after administration. A significant increase in heart rate was also observed. All the effects were correlated with the dose. Side effects occurred mainly after the 30 mg dose. Thus, cadralazine, in a single oral dose in man, showed good antihypertensive activity starting from the 15 mg dose, and its effect was dose-related, slow in onset and long-lasting.