The antihypertensive efficacy both of angiotensin converting enzyme (ACE) inhibitors and thiazide diuretics has been claimed to be influenced by plasma renin activity, which declines with age and is low in blacks. In a double-blind, placebo-controlled, double-dummy, randomized, parallel-group preliminary study, the antihypertensive efficacy and tolerability of the ACE inhibitor enalapril (20 mg day-1) and hydrochlorothiazide (50 mg day-1) were evaluated and compared for 4 weeks in 20 African patients with essential hypertension. The two groups had similar baseline clinical features and serum Na+ and K+ levels. Hydrochlorothiazide caused a significant and sustained fall in erect blood pressure with a reflex tachycardia. Enalapril exerted only a modest antihypertensive action, but significantly reduced erect heart rate. Direct comparison of hydrochlorothiazide- and enalapril-induced hypotension suggested a greater fall in subjects on the thiazide. The 95% confidence limits for the thiazide-enalapril difference in antihypertensive action at the end of the study was 39.5 to -7.5 mm Hg systolic and 22.0 to -6.6 mm Hg diastolic. The maximal blood pressure fall after hydrochlorothiazide was positively correlated with age (r = 0.50; p less than 0.05), whilst that of enalapril was inversely related age to (r = -0.57, p less than 0.05). The results are compatible with the notion that ACE inhibitor monotherapy may be less effective than thiazide diuretic treatment in African and black patients with essential hypertension. The findings also support the concept that age and racial factors may influence the response to antihypertensive treatment.

SummaryWe compared the efficacy and tolerability of oral piroxicam 1 mg/kg/day with soluble aspirin given at 100 mg/kg/day taken four-hourly in 58 patients with sickle cell anaemia and severe ostcoarticular painful attacks requiring hospitalization in a randomized, paralleled study. Main investigational criteria were pain relief, limitation of movement, fever, and insomnia or agitation. Both groups were well-matched at the commencement of therapy but most patients on piroxicam showed remarkable and significant pain relief and improvement in other parameters within 24 h. Unwanted effects were absent in the piroxicam-treated group whereas those treated with aspirin experienced nausea and vomiting. There were no significant changes in liver function tests with both forms of treatment. Oral piroxicam is an effective and safe treatment in the management of the osteoarticular painful crisis in sickle cell anaemia. It might prevent the use of parenteral analgesics and hospitalization and reduce the loss of school hours in patients who are being treated for bone pain crises that characterize sickle cell anaemia.

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In a preliminary double‐blind study in African patients with heart failure, enalapril tended to increase treadmill exercise duration relative to placebo (95% confidence interval‐11.5 to 144.3 s). This was associated with a significant improvement in NYHA functional class and subjective well being (P less than 0.05 ANOVA) with a concomitant reduction in body weight (P less than 0.05 ANOVA). It significantly increased pulse pressure during forearm isometric exercise (P less than 0.05 ANOVA), but the Valsalva's manoeuvre and the orthostatic response were unchanged.

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Serum bilirubin concentrations were investigated in neonatal rats. High concentrations were found on day 1 falling to adult values by day 4. Oxytocin (500 IU/kg) given subcutaneously to the dams on day 22 of pregnancy increased bilirubin concentrations in neonatal rats. This dose of oxytocin shortened gestational length but increased the neonatal death rate. Oxytocin (500 IU/kg) also increased uterine contractions on day 22 of pregnancy, measured using intrauterine balloons inserted on day 19 of pregnancy. Rats delivered by Caesarian section at the same gestational age as the oxytocin-treated group did not exhibit hyperbilirubinaemia. Prostaglandin F_2α (300 μg/kg) administered intramuscularly on day 20 of pregnancy was found to advance parturition and produced a small rise in serum bilirubin concentrations in neonatal rats. The rat could serve as a model for investigating the mechanisms of neonatal hyperbilirubinaemia which has been suggested to occur after the use of oxytocin or prostaglandins in the human.