Randomised double-blind comparison of placebo and active treatment for older patients with isolated systolic hypertension. The Systolic Hypertension in Europe (Syst-Eur) Trial Investigators

BACKGROUND

Isolated systolic hypertension occurs in about 15% of people aged 60 years or older. In 1989, the European Working Party on High Blood Pressure in the Elderly investigated whether active treatment could reduce cardiovascular complications of isolated systolic hypertension. Fatal and non-fatal stroke combined was the primary endpoint.

METHODS

All patients (> 60 years) were initially started on masked placebo. At three run-in visits 1 month apart, their average sitting systolic blood pressure was 160-219 mm Hg with a diastolic blood pressure lower than 95 mm Hg. After stratification for centre, sex, and previous cardiovascular complications, 4695 patients were randomly assigned to nitrendipine 10-40 mg daily, with the possible addition of enalapril 5-20 mg daily and hydrochlorothiazide 12.5-25.0 mg daily, or matching placebos. Patients withdrawing from double-blind treatment were still followed up. We compared occurrence of major endpoints by intention to treat.

FINDINGS

At a median of 2 years' follow-up, sitting systolic and diastolic blood pressures had fallen by 13 mm Hg and 2 mm Hg in the placebo group (n = 2297) and by 23 mm Hg and 7 mm Hg in the active treatment group (n = 2398). The between-group differences were systolic 10.1 mm Hg (95% CI 8.8-11.4) and diastolic, 4.5 mm Hg (3.9-5.1). Active treatment reduced the total rate of stroke from 13.7 to 7.9 endpoints per 1000 patient-years (42% reduction; p = 0.003). Non-fatal stroke decreased by 44% (p = 0.007). In the active treatment group, all fatal and non-fatal cardiac endpoints, including sudden death, declined by 26% (p = 0.03). Non-fatal cardiac endpoints decreased by 33% (p = 0.03) and all fatal and non-fatal cardiovascular endpoints by 31% (p < 0.001). Cardiovascular mortality was slightly lower on active treatment (-27%, p = 0.07), but all-cause mortality was not influenced (-14%; p = 0.22).

INTERPRETATION

Among elderly patients with isolated systolic hypertension, antihypertensive drug treatment starting with nitrendipine reduces the rate of cardiovascular complications. Treatment of 1000 patients for 5 years with this type of regimen may prevent 29 strokes or 53 major cardiovascular endpoints.

Mortality and morbidity results from the European Working Party on High Blood Pressure in the Elderly trial

A double-blind randomised placebo-controlled trial of antihypertensive treatment was conducted in patients over the age of 60. Entry criteria included both a sitting diastolic blood pressure on placebo treatment in the range 90-119 mm Hg and a systolic pressure in the range 160-239 mm Hg. 840 patients were randomised either to active treatment (hydrochlorothiazide + triamterene) or to matching placebo. If the blood pressure remained raised, methyldopa was added to the active regimen and matching placebo in the placebo group. An overall intention-to-treat analysis, combining the double-blind part of the trial and all subsequent follow-up, revealed a non-significant change in total mortality rate (-9%, p = 0.41) but a significant reduction in cardiovascular mortality rate (-27%, p = 0.037). The latter was due to a reduction in cardiac mortality (-38%, p = 0.036) and a non-significant decrease in cerebrovascular mortality (-32%, p = 0.16). In the double-blind part of the trial, total mortality rate was not significantly reduced (-26%, p = 0.077). Cardiovascular mortality was reduced in the actively treated group (-38%, p = 0.023), owing to a reduction in cardiac deaths (-47%, p = 0.048) and a non-significant decrease in cerebrovascular mortality (-43%, p = 0.15). Deaths from myocardial infarction were reduced (-60%, p = 0.043). Study-terminating morbid cardiovascular events were significantly reduced by active treatment (-60%, p = 0.0064). Non-terminating cerebrovascular events were reduced (-52%, p = 0.026), but the non-terminating cardiac events were not (+3%, p = 0.98). In the patients randomised to active treatment there were 29 fewer cardiovascular events and 14 fewer cardiovascular deaths per 1000 patient years during the double-blind part of the trial.

Effect of cysteinyl-leukotriene receptor antagonist ICI 204.219 on allergen-induced bronchoconstriction and airway hyperreactivity in atopic subjects

The effects of a highly selective leukotriene D4 receptor antagonist, ICI 204.219, on allergen-induced bronchoconstriction and changes in airway reactivity were evaluated in a double-blind, placebo-controlled, crossover trial. Ten atopic subjects were selected for the study on the basis of an immediate fall in forced expiratory volume in 1 s (FEV1) of at least 15% and a least a doubling dose fall in their PC20-histamine (the concentration of histamine needed to reduce FEV1 by 20%) after antigen challenge. Baseline PC20-histamine was determined before the ingestion of a single oral 40 mg dose of ICI 204.219 or matched placebo. 2 h later subjects were challenged with aerosolised allergen; FEV1 was measured for the next 6 h then PC20-histamine was remeasured. Two subjects did not complete the study for reasons not related to the trial medication. ICI 204.219 significantly attenuated the early and late phase bronchoconstriction to inhaled allergen (mean treatment difference in area under the FEV1-time curves 2529 [95% Cl 1085-3972] delta %FEV1.min; p less than 0.005: and 3537 [528-6545] delta %FEV1.min; p less than 0.03) and suppressed the allergen-induced increase in non-specific bronchial reactivity (mean treatment difference 1.03 [0.34-1.71] doubling dilutions of histamine; p less than 0.01). These findings suggest that ICI 204.219 may be a disease-modifying agent in asthma. Further studies are under way to evaluate its clinical efficacy.

Urinary leukotriene E4 after antigen challenge and in acute asthma and allergic rhinitis

The leukotrienes LTC4, D4, and E4 are potent bronchoconstrictor agents and are thought to have an important role in asthma. Urinary LTE4, a stable urinary end-product of LTC4 and LTD4, was measured, by means of high-performance liquid chromatography and radioimmunoassay. LTE4 excretion followed a log-normal distribution in twenty-nine healthy controls, with a geometric mean of 23.8 (95% confidence interval 19.9-28.2) ng/mmol creatinine. Urine was collected from eight atopic subjects for 3 h after antigen inhalation and a control urine collection was made a week later at the same time of day. Urinary LTE4 was significantly higher after antigen challenge than in the control sample (153.7 [87.1-271.3] vs 23.5 [13.7-69.5] ng/mmol creatinine; p less than 0.01). Urinary LTE4 was also measured in twenty patients with severe acute asthma and nine patients with seasonal allergic rhinitis. Mean urinary LTE4 was higher in the asthmatic patients (78.3 [46.5-131.8] ng/mmol creatinine) than in normal subjects (p less than 0.01), although there was substantial overlap into the normal range. The urinary LTE4 values of the rhinitis patients were within the normal range whether or not they had symptoms. LTC4 and LTD4 were also found in bronchoalveolar lavage fluid from one of the three atopic subjects challenged with antigen before lavage, and in a single patient who underwent lavage after admission with severe acute asthma. These studies provide evidence that leukotrienes are released in vivo in man after antigen challenge and in acute asthma.

Hydralazine-induced systemic lupus erythematosus: influence of HLA-DR and sex on susceptibility

26 patients with systemic lupus erythematosus (SLE) induced by treatment with the antihypertensive drug hydralazine were investigated to determine if predisposition to the toxic effect was associated with an HLA-DR antigen. 25 of the 26 patients were slow acetylators. The group was compared with three others (1) 113 healthy subjects, untested for acetylator phenotype, (2) 16 slow-acetylator hypertensive patients treated with hydralazine for more than a year without developing SLE, and (3) 20 patients with idiopathic SLE. The frequency of HLA-DR4 (73%) was significantly higher in the group with hydralazine-induced SLE than in the other groups (respectively 33%, 25%, and 25%). The ratio of women to men affected was 4:1. If the slow acetylators treated with hydralazine were analysed as one group, it was observed that all women with DR4 developed hydralazine-induced SLE; the only men to do so were those with DR2 who were receiving 200 mg hydralazine per day. These observations have led us to suggest guide lines for hydralazine therapy and point to a striking association between an HLA-DR antigen and an adverse reaction to a therapeutic agent. It was also noted that the distribution of DR antigens in the hydralazine-SLE patients was significantly different from that in the group with idiopathic SLE. This supports the view that the syndromes are separate entities.

Prostacyclin is not a circulating hormone in man

A highly specific stable isotope dilution assay for plasma 6-oxo-prostaglandin F1 alpha has been developed. The method employs capillary column gas chromatography coupled with negative ion chemical ionisation mass spectrometry. The limit of sensitivity of the assay is 0.5 pg.m1(-1). Concentrations of 6-oxo-prostaglandin F1 alpha in the plasma of 20 healthy volunteers determined by this assay were all below 3 pg.m1(-1). The levels were much lower than any previously reported and confirms that prostacyclin is not a circulating hormone in man under normal physiological conditions.

Clinical pharmacology and pharmacokinetics of clonidine

A 300-mug oral dose of clonidine was administered to 5 normal volunteers and measurements of plasma concentration and effects upon blood pressure, heart rate, circulatory reflexes, sedation, and dry mouth were made for the following 8 hr. The plasma concentration rose to a peak of 1.02 +/- 0.52 ng/ml (SD) at 90 min and fell with a mean half-life of 12.7 hr. Blood pressure of the group fell from 111.0/77.0 to 87.2/60.4 after 3 hr and was 95.2/62.2 mm Hg at 8 hr. Heart rate in recumbency was slowed. Marked sedation and a fall in salivary flow followed the same time-course as the plasma concentration. The cold pressor response was reduced but the Valsalva overshoot was little affected.

Pharmacokinetics and concentration-effect relationships of intervenous and oral clonidine

The kinetics of the disposition of intravenous and oral clonidine in five normotensive subjects have been determined. It is proposed that a two-compartment model adequately describes the disposition of the drug. The drug is rapidly distributed (t1/2alpha = 10.8 +/- 4.7 min) but slowly elimainated (t1/2beta = 8.5 +/- 0.9 hr). The bioavailability of oral clonidine in the tablets tested averaged 75.2% and 40 to 50% of the bioavailable dose is excreted unchanged in urine. Renal clearance of the drug showed considerable intersubject variation (1.82 +/- 0.34 ml/min/kg) and exceed the calculated glomerular filtration rate in some subjects. Oral and intravenous clonidine induced significant falls in blood pressure (greater than 20/15 mm Hg) in our normotensive subjects and consistently caused marked sedation and dryness of the mouth. Sedation and salivary flow correlated with plasma clonidine concentration over the range 0 to 4 ng/ml. Falls in blood pressure were related to plasma concentration to 1.5 to 2 ng/ml but at higher concentrations the hypotensive effect was attenuated.

Absorption and metabolism of nicotine from cigarettes

Eight men volunteers each smoked a single cirgarette containing 14C-nicotine and gave arterial blood samples during and for 50 minutes after smoking. The maximum concentration of nicotine in the arterial blood ranged from 31 to 41 mug/l in four regular cigarette smokers who inhaled. Two non-smokers achieved maximum levels of 2 and 4 mug/l. On a separate occasion two of the inhalers received 1 mg. 14C-nicotine in 10 divided doses injected intravenously. In both cases the peak arterial nicotine concentrations bore a similar relationship to the intravenous dose, as did the peak nicotine concentrations to the retained doses during smoking.

Side effects of hypotensive agents evaluated by a self-administered questionnaire

A self-administered symptom questionnaire was completed by 477 patients in a hypertension clinic. The complaints of the patients were analysed according to the type of therapy being given and the dose of drug taken. Methyldopa therapy was associated with sleepiness, weakness of the limbs, sleeping longer at night, and rising more frequently at night to pass urine. Diarrhoea, impotence, failure of ejaculation, blurred vision, depression, and the symptoms of postural hypotension were not related to methyldopa therapy. Bethanidine administration was related to postural hypotension, impotence, and failure of ejaculation but not to weakness of the limbs, blurred vision, depression, or diarrhoea. Patients receiving guanethidine complained of postural hypotension, failure of ejaculation, and had their bowels open more frequently. Similarly, patients receiving propranolol had an increased frequency of defaecation but also tended to complain of weakness of the limbs.Considering each drug individually, 5% of patients failed to take the prescribed dose of diuretic whereas

IUPHAR-DB: the IUPHAR database of G protein-coupled receptors and ion channels

The IUPHAR database (IUPHAR-DB) integrates peer-reviewed pharmacological, chemical, genetic, functional and anatomical information on the 354 nonsensory G protein-coupled receptors (GPCRs), 71 ligand-gated ion channel subunits and 141 voltage-gated-like ion channel subunits encoded by the human, rat and mouse genomes. These genes represent the targets of approximately one-third of currently approved drugs and are a major focus of drug discovery and development programs in the pharmaceutical industry. IUPHAR-DB provides a comprehensive description of the genes and their functions, with information on protein structure and interactions, ligands, expression patterns, signaling mechanisms, functional assays and biologically important receptor variants (e.g. single nucleotide polymorphisms and splice variants). In addition, the phenotypes resulting from altered gene expression (e.g. in genetically altered animals or in human genetic disorders) are described. The content of the database is peer reviewed by members of the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR); the data are provided through manual curation of the primary literature by a network of over 60 subcommittees of NC-IUPHAR. Links to other bioinformatics resources, such as NCBI, Uniprot, HGNC and the rat and mouse genome databases are provided. IUPHAR-DB is freely available at http://www.iuphar-db.org.

Heparin kinetics in venous thrombosis and pulmonary embolism

The response to a standard dose of heparin was studied in 20 patients with venous thromboembolism. The heparin regimen consisted of intravenous injection of 70 units per kg, followed after 90 minutes by a maintenance dose of 400 units per kg per 24 hours given by continuous infusion. Plasma heparin activity and the activated partial thromboplastin time (APTT) were measured at intervals to determine clearance of the initial injection and the response to maintenance dose. Large inter-individual variations were found in the anticoagulant effect and these were due in part to differences in heparin clearance and in part to differences in the APTT response to given amounts of heparin (heparin effect index). The heparin half-life was 63 +/- 15 minutes when plasma heparin activities were used for this calculation and 84 +/- 71.5 minutes when the APTT was used. These results are similar to values previously reported in normal volunteers. Four of the 20 patients had pulmonary embolism and in these heparin half-life was significantly shortened (P less than 0.005).

Glucose intolerance during diuretic therapy. Results of trial by the European Working Party on Hypertension in the Elderly

119 elderly, hypertensive patients were followed-up for 1 year and 48 for 2 years in a double-blind, randomised, controlled trial in which they received either placebo or 25-50 mg hydrochlorothiazide and 50-100 mg of triamterene daily. Half of the active treatment group also received 250 mg to 2 g methyldopa daily. After 2 years the active treatment group had an average increase in fasting blood-sugar of 9.6 mg/dl compared with an average fall of 3.1 mg in the placebo group (p less than 0.001). Blood-glucose rose by an average of 26.6 mg/dl in the active group when determined 1 hour after 50 g oral glucose and decreased by an average of 5.3 mg/dl in patients who had been on placebo for two years (p less than 0.05). The hyperglycaemic effect of diuretics appeared to be related to potassium loss since, in both groups, impairment of glucose tolerance was most marked in those in whom the serum-potassium decreased over the 2 years.

Angiotensin-converting-enzyme gene insertion/deletion polymorphism and response to physical training

BACKGROUND

The function of local renin-angiotensin systems in skeletal muscle and adipose tissue remains largely unknown. A polymorphism of the human angiotensin converting enzyme (ACE) gene has been identified in which the insertion (I) rather than deletion (D) allele is associated with lower ACE activity in body tissues and increased response to some aspects of physical training. We studied the association between the ACE gene insertion or deletion polymorphism and changes in body composition related to an intensive exercise programme, to investigate the metabolic effects of local human renin-angiotensin systems.

METHODS

We used three independent methods (bioimpedance, multiple skinfold-thickness assessment of whole-body composition, magnetic resonance imaging of the mid-thigh) to study changes in body composition in young male army recruits over 10 weeks of intensive physical training.

FINDINGS

Participants with the II genotype had a greater anabolic response than those with one or more D alleles for fat mass (0.55 vs -0.20 kg, p=0.04 by bioimpedance) and non-fat mass (1.31 vs -0.15 kg, p=0.01 by bioimpedance). Changes in body morphology with training measured by the other methods were also dependent on genotype.

INTERPRETATION

II genotype, as a marker of low ACE activity in body tissues, may conserve a positive energy balance during rigorous training, which suggests enhanced metabolic efficiency. This finding may explain some of the survival and functional benefits of therapy with ACE inhibitors.

Attenuation of hypotensive effect of propranolol and thiazide diuretics by indomethacin

The effects of 100 mg indomethacin daily for three weeks on blood pressure and urinary excretion of prostaglandin F2 alpha were studied in a double-blind, placebo-controlled comparison of two groups of patients with essential hypertension, eight receiving propranolol and seven thiazide diuretics. Compared with placebo, adding indomethacin to the patients' established antihypertensive treatment increased blood pressure by 14/5 Hg supine and 16/9 mm Hg erect in the patients receiving propranolol, and by 13/9 mm Hg supine and 16/9 mm Hg erect in the patients receiving thiazide diuretics (all p less than or equal to 0.05). The excretion of the major urinary metabolite of prostaglandin F2 alpha was reduced by 67% in the propranolol-treated patients and by 57% in those receiving a thiazide diuretic. Body weight increased by 0 . 8 kg (propranolol) and 1 . 1 kg (thiazide diuretic) when indomethacin was given, but there were no significant changes in creatinine clearance, urinary sodium excretion, or packed cell volume in either treatment group. These results suggest that products formed by the arachidonic acid cyclo-oxygenase contribute to the regulation of blood pressure during treatment with both propranolol and thiazide diuretics. Inhibition of the cyclo-oxygenase with indomethacin partially antagonises the hypotensive effect of these drugs.

Efficacy of antihypertensive drug treatment according to age, sex, blood pressure, and previous cardiovascular disease in patients over the age of 60

Results of the European Working Party on High Blood Pressure in the Elderly (EWPHE) trial have been analysed in relation to age, sex, blood pressure, and previous cardiovascular disease. Cardiovascular mortality and the cardiovascular study-terminating events were significantly and independently related to treatment, age, cardiovascular complications at randomisation, and systolic but not diastolic blood pressure. The benefits of treatment observed in the trial seemed to be independent of entry blood pressure and the presence or absence of cardiovascular complications at entry. There was some evidence that treatment effect decreases with advancing age. Little or no benefit from treatment could be demonstrated in patients over the age of 80 years, the great majority of whom were women.

The Concise Guide to PHARMACOLOGY 2013/14: overview

The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties from the IUPHAR database. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. This compilation of the major pharmacological targets is divided into seven areas of focus: G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors & Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and GRAC and provides a permanent, citable, point-in-time record that will survive database updates.