The benefits and risks of treating mild to moderate hypertension

The risks and benefits of treating mild to moderate hypertension (defined as a diastolic blood pressure level between 90-114 mm Hg) were quantified in order to assist clinical decision making. Presenting such information ought to be an essential part of the process of obtaining the patient's consent for treatment. Using estimates from clinical trials that antihypertensive drug therapy reduces all-cause mortality by 11% and stroke incidence by 39%, the benefits of treatment--expressed as the average number of people needing to be treated annually in order to prevent one death--ranges from 333 to 3393 in men, and from 508 to 5094 in women. The average number of people needing to be treated annually to prevent one stroke ranges from 281 to 4292 in men, and from 253 to 13,477 in women. The benefits of treatment are greatest in men, in the older age groups, and at higher diastolic blood pressure levels. Compared to the benefits, the annual risk of developing a side effect of the medication is much higher.

A comparison of the extent and duration of hypokalaemia following three nebulized beta 2-adrenoceptor agonists

The hypokalaemic effects of equal doses (5 mg) of fenoterol, salbutamol, terbutaline and an equal volume of saline administered by nebulization were compared in eight healthy subjects. Plasma potassium was measured at 15-min intervals for 60 min and at 90 min, 2, 4 and 6 h following administration. Fenoterol, salbutamol and terbutaline all significantly decreased plasma potassium when compared to saline; however, the magnitude and duration of this effect differed between the active agents. Both fenoterol and terbutaline significantly reduced plasma potassium for 4 h whereas salbutamol was only different from 30 to 120 min. The maximum decrease occurred with fenoterol (-0.78 mmol/l), followed by terbutaline (-0.70 mmol/l) and salbutamol (-0.33 mmol/l). Both terbutaline and fenoterol had a significantly greater effect compared with salbutamol. When administered by nebulization fenoterol and terbutaline are likely to have a greater hypokalaemic effect than salbutamol and this effect is likely to be more long lasting.

Variability in antihypertensive drug therapy in general practice: results from a random national survey

A random national survey of 50 general practitioners was undertaken to ascertain current trends in the pharmacological management of hypertension. Forty general practitioners entered the study, and scripts written by them over a two month period in 1988 were collected and recorded by the pharmaceutical pricing offices of the health department. The general practitioners provided details on whether the script had been written for hypertension, as well as the age and sex of the patients. Information from 37 general practitioners was available for study, involving 2675 scripts written for hypertension for 1858 patients. Sixty point two percent of the treated hypertensives were female, and 58.9% were aged over 60 years. The most commonly prescribed antihypertensives were the diuretics (47.1% of patients) and beta blockers (47.9%). They were followed by angiotensin converting enzyme inhibitors (18.2%) and calcium antagonists (9.7%). There was substantial variability in the prescription of antihypertensives with respect to the age and sex of the patients treated; the mean costs and duration of supply of different generic drug types; and the prescribing habits of general practitioners. By generic type, the mean monthly costs of therapy ranged from $3.77 (diuretics) to $48.19 (calcium antagonists). The age and sex adjusted geometric mean script costs ranged from $17.78 to $49.11 per month (median: $29.30). It seems unlikely that the observed degree of variability is explained by differences in the severity of hypertension between general practice populations.

Individual variability of amiodarone distribution in plasma and erythrocytes: implications for therapeutic monitoring

The complexity of amiodarone disposition in blood and tissues gives rise to difficulty in determination of optimal therapeutic monitoring strategies. We have defined the within-patient variability of plasma and erythrocyte amiodarone and desethylamiodarone concentrations and electrocardiogram intervals [PR and corrected QT (QTc)] in 27 patients each sampled on three to four occasions during long-term stable amiodarone therapy. All individual repeated measurements were included in the concentration-effect analysis. The mean within-patient coefficients of variation for amiodarone and desethylamiodarone were significantly greater in erythrocytes, 46.0 and 24.5%, respectively, compared with plasma, 12.7 and 12.3%. Amiodarone and desethylamiodarone were significantly greater in erythrocytes, 46.0 and 24.5%, respectively, compared with plasma, 12.7 and 12.3%. Amiodarone and desethylamiodarone were strongly correlated (r = 0.29 p less than 0.004). There was a 10-fold variability in erythrocyte amiodarone for a given plasma level. These data emphasize the highly variable cellular distribution of amiodarone and desethylamiodarone in the same patient on stable dosage over time. Plasma amiodarone was significantly correlated with dosage (r = 0.98), and percent change in QTc, (r = 0.56, p less than 0.0001), but there was a fourfold variation in plasma amiodarone for a given QTc. Side-effect frequency was not related to plasma or erythrocyte amiodarone or desethylamiodarone concentrations. A clinically useful relationship between plasma concentration and effect could not be consistently demonstrated for amiodarone in the same individual during stable dosage.

The blocked bed: a prospective study

A prospective study of all patients (15 years and over) admitted to acute medical beds at a medium sized general hospital was carried out. For each patient, demogaphic data, day and time of admission, consultant in charge and the main reason for admission, were recorded. The patients hospital stay was analysed to determine the extent of the bed blocking problem. Sixty-two percent of total days stay required acute medical intervention, 32% was spent receiving nursing care only, 4% paramedical activities and 3% awaiting outside medical consultations. The three major factors found to influence total days stay were age, living situation and reason for admission. Patients over 75 years, living alone or who were admitted with a cerebrovascular accident/for nursing care were identified as bed blockers. An age related geriatric service may speed up the recovery of these patients and result in a more appropriate use of hospital resources.

Comparison of the recovery characteristics of diazepam and midazolam

A double-blind crossover comparison of efficacy and recovery from midazolam 5 mg and diazepam (in propylene glycol) 10 mg was undertaken in eight volunteer subjects. It was found that midazolam was significantly more potent in this dose ratio than diazepam, helping to explain the finding of previous studies that the recovery from midazolam and diazepam in a 1:2 dose ratio is comparable.

Comparison of a fenoterol/ipratropium combination with salbutamol from metered dose inhalers in subjects with chronic partially reversible airways obstruction

We have compared the acute bronchodilator response following salbutamol 200 micrograms and fenoterol 200 micrograms with ipratropium 80 micrograms, from metered dose inhalers in ten subjects with severe partially reversible airflow obstruction. Treatment with the combination resulted in a similar degree of bronchodilation but with a significantly longer duration of action.

Hyperammonaemia and hepatotoxicity during chronic valproate therapy: enhancement by combination with other antiepileptic drugs

Erythrocyte (ENH3) and plasma (PNH3) ammonia levels, liver function tests and plasma valproate concentration were measured in 81 epileptic patients, comprising three therapeutic groups: Group 1 (23 patients) received sodium valproate (VPA) monotherapy, group 2 (33 patients) received sodium valproate combined with phenytoin, carbamazepine, phenobarbitone and/or primidone and group 3 (25 patients) received one or more of these anti-epileptic drugs without sodium valproate. The mean ENH3 and PNH3 of patients in group 1 (41.1 +/- 30.7 mumol l-1 and 37.1 +/- 31.8 mumol l-1, respectively) and group 2 (44.5 +/- 21.3 and 37.6 +/- 21.4 mumol l-1, respectively) were significantly (P less than 0.01) higher than those in group 3 (28.7 +/- 10.6 and 21.5 +/- 7.8 mumol l-1, respectively) and the reference range (30.1 +/- 7.9 and 20.8 +/- 5.7 mumol l-1, respectively). Hyperammonaemia was more prevalent amongst patients in group 2, for both ENH3 (45.5%) and PNH3 (54.6%), than amongst patients in group 1 (30.4% and 52.2%, respectively) and group 3 (8% and 8%, respectively). There was a significant (P less than 0.05) positive correlation between plasma VPA and total bilirubin concentrations. Chronic VPA therapy was also associated with an increase in bilirubin concentrations measured on average four months apart.