P-BLOCKERS TAKE THE PRESSURE OFF HYPERTENSION

Combination tablets: atenolol-chlorthalidone is more effective than pindolol-clopamide 38 hypertensive patients entered a single-blind crossover study to assess the effects of2 fl-blockerjdiuretic compound tablets on blood pressure and pulse rate. Patients received tablets of 1 OOmg atenolol + 25mg chlorthalidone or 1 Omg pindolol + 5mg clopamide, one tablet daily for 4 weeks on each combination in random order. BP levels were significantly lower with the atenolol/chlorthalidone combination than with pindololfclopamide: mean lying BP was reduced from a baseline level of 175.3/108.0 to 148.5/91.6 on the former and to 158.0/98.5mm Hg on the latter. Diastolic pressure of less than 95mm Hg was achieved in 25 patients on atenololfchlorthalidone and in only 11 on pindolol/clopamide. To achieve satisfactory BP control the dosage of the pindolol-containing tablet may have to be increased at the risk of a possible fall in compliance, increased side effects and increased cost of treatment (studies have shown a fall in compliance as the daily dose increases). Side effects and complaints occurred in 16 patients taking atenololfchlor­thalidone and in 19 patients receiving pindololjclopamide, and were little different from those reported in other {3-blocker studies. They included palpitations, GI problems, insomnia, tiredness, headaches, thirst and general malaise. Pulse rate was slightly increased on pindololfclopamide but atenololfchlorthalidone had no effect. The initial mean pulse rate was 73.8 beats/min, and while on atenololfchlorthalidone and pindololjclopamide the mean pulse rates were 72.5 and 78.3 beats/min, respectively). In conclusion, once-daily atenololfchlorthalidone was a more effective treatment for mild hypertension than once daily pindololfclopamide. However, better BP control may be achieved with an increase in the dosage of the pin­dololfclopramide combination. Douglas-Jones, A.P. and Tweed, J.A.: Acta Therapeutica 8: 345 (No 4 1982)

Nadolol-bendroflumethiazide is more effective than either drug alone ... 195 patients with essential hypertension completed a double-blind trial designed to compare 8 weeks' treatment with nadolol (59 patients), or bendroflumethiazide (70 patients) or combined nadolol + bendroflumethiazide (66 patients). A pretreatment placebo period was used to select suitable subjects for the study (diastolic BP of at least lOOmm Hg). Initial doses of bendroflumethiazide Smg and nadolol 80mg were given, alone or in combination. Patients with persistent hypertension at 4 weeks had their doses doubled. The fall in diastolic BP (supine and erect) compared with pretreatment readings, was significantly greater on combined therapy than on monotherapies, at both 4 and 8 weeks. Doubling of the initial dose was necessary in fewer patients on combined therapy (18%) than in patients on bendroflumethiazide (54%) or on nadolol (36%). The proportion of patients who became normotensive (supine diastolic BP less than 90mm Hg) was 82% on combined therapy, 48% on diuretic, and 53% on P-blocker. No reduction in antihypertensive action was seen in 102 patients who completed 3-5 months on combined therapy. Drug-related adverse reactions occurred in 39 (19%) of patients in the double-blind study phase and necessitated drug withdrawal in 3 patients on bendroflumethiazide (2 nausea and vomiting, 1 orthostatic hypotension), 3 patients on nadolol (1 asthma, I diarrhoea, 1 orthostatic hypotension) and l patient on combined therapy (hyperosmolar non-ketotic hyperglycaemia). The frequency of adverse reactions was similar (15%) in the long term study of com­bined therapy, and drug withdrawal was necessary in 2 patients (I postural dizziness, 1 hyperosmolar non-ketotic hyperglycaemia). Hypokalaemia on bendroflumethiazide and bradycardia on nadolol (alone and in combination) did not present a significant clinical problem. Herman, T.S.: Royal Society of Medicine International Congress and Symposium Series No 51: 59 (1982)

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