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| Year : 1985 | Volume
: 31
| Issue : 4 | Page : 187-91 |
Atenolol as an anti-hypertensive drug.
Kale PA, Soman RN
How to cite this article:
Kale P A, Soman R N. Atenolol as an anti-hypertensive drug. J Postgrad Med 1985;31:187 |
The value of ß adrenoceptor blocking agents in the treatment of hypertension was first demonstrated by Prichard and Gillam[2] using propranolol. Atenolol is a B, cardioselective adrenoceptor blocking agent without partial agonist activity or membrane stabilizing activity. It is effective with once daily regimen, has a relatively flat dose-response curve and a low incidence of CNS side effects.[3],[4]The objective of the present study was to assess the antihypertensive efficacy and the safety of atenolol in the doses of 50 mg and 100 mg and its combination with chlorthalidone 25 mg in patients with essential hypertension.
Thirty seven patients attending the hypertension clinic of the K.E.M. Hospital and having uncomplicated essential hypertension with a supine diastolic BP of 90-120 mm Hg were studied. Patients with associated bronchial asthma, diabetes mellitus, brady-arrhythmias and congestive cardiac failure were excluded. Previous antihypertensive treatment was withdrawn for one week prior to the study. Atenolol 50 and 100 mg, atenolol 100 mg with chlorthalidone 25 mg, and placebo were all supplied as identical looking, coded capsules and the double blind design of the study was maintained. Every patient was given a week's supply and was asked to take daily dose once in the morning. Blood pressures and heart rate were measured at weekly interva15 after 10 minutes of rest in the supine position after the patient had been standing for 2 minutes.
The dosage regimens A, B, C and D for patients in group I, II, III were divided as follows:
All the patients (n = 37) received placebo capsules (A) for first two weeks and atenolol 50 mg once daily (B) for the next two weeks. Patients whose supine diastolic blood pressure was 90 mm Hg or lower at the end of this period were asked to continue with atenolol 50 mg for further 2 weeks (group I) (n = 14). Those patients whose supine diastolic BP remained above 90 mm Hg were randomly divided into 2 groups (Group II and III). Group II (n = 12) received atenolol 100 mg (C) and group III (n = 11) received atenolol 100 mg plus chlorthalidone 25 mg (D) for 2 weeks.
Results were statistically analysed using Student's 't' test. Liver function tests, serum electrolytes, hemogram, urine, stool examination and electrocardiogram were carried out at the beginning and after four and six weeks on therapy.
Students in all the three groups showed a greater reduction in the mean heart rate on drug treatment or placebo[Table 1].
[Table 2]to[Table 5]show the control of blood pressure with different treatment regimens. As compared to the placebo, atenolol (50 mg) produced a significant fall in both the mean systolic and diastolic blood pressures in all the groups o: patients. The patients in group II and III showed more fall in the mean, diastolic, supine and standing, blood pressures when the regimen C and D were given to them respectively[Table 3]and[Table 5]respectively).
There were no significant side-effects during the study period. Placebo gave rise to weakness in 2 patients, headache in 2 and chest pain in 4. Atenolol 50 mg produced weakness in 1 patient, bodyache in 1 and chest pain in l. Atenolol 100 mg caused weakness in 2 and dizziness in 1 patients. The combination of atenolol 100 mg with chlorthalidone 25 mg produced weakness in one and chest pain in one patient.
Atenolol was well tolerated with minimum side effects. It lowered supine and standing, systolic and diastolic blood pressures in all the patients in a single daily dose. Patients who were not controlled with atenolol 50 mg were controlled with atenolol 100 mg or atenolol 100 mg plus chlorthalidone 25 mg. Due to the small number of patients in each subgroup, it is difficult to draw firm conclusion about the efficacy of the combination of atenolol and chlorthalidone versus atenolol alone.
Atenolol, with its daily single dose schedule and efficacy, would improve patient compliance as compared to other anti-hypertensive drugs with multidose daily schedules. Its cardioselectivity is an additional advantage.
| 1. | Ambrosioni. E., Cost, F. V., Montebugnoli, L., Bassein, L., Marchesini, B. and Magnani, B.: Comparison of antihypertensive efficacy of atenolol, oxprenolol and pindolol at rest and during exercise. Drugs; 25 (Suppl. 2): 30-36, 1983.  |
| 2. | Prichard, B. N. C. and Gillam, P.M.S.: Treatment of hypertension with propranolol. Brit. Med. J. 2: 725-727, 1964. |
| 3. | Waal-Manning, H. J.: Atenolol and three non-selective betablockers in hypertension. Clin. Pharmacol. and Therap., 25: 5-18, 1979. |
| 4. | Zacharias, F. J., Hayes, P. J. and Cruickshank, J. M.: Atenolol in hypertension: a double-blind comparison of the response to three different doses. Postgrad. Med. J., 53 (Suppl. 3): 114-115, 1977. |
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