Br. J. clin. Pharmac. (1978), 8, 129S-133S
MONOTHERAPY WITH LABETALOL FOR HYPERTENSIVE PATIENTS WITH NORMAL AND IMPAIRED RENAL FUNCTION F.D. THOMPSON, A.M. JOEKES
&
M.M. HUSSEIN
St Peter's Group of Hospitals, and Institute of Urology, London
1 Labetalol was given to 41 hypertensive patients in a divided dosage of 150-2,400 mg daily for periods ranging from 1-64 months. 2 Monotherapy with labetalol was adequate in 12 out of 19 patients with essential hypertension and in 15 out of the 22 with renal hypertension. 3 Following a single dose of labetalol 200 mg orally a hypotensive response was seen between 1.5 and 2 hours. 4 In the doses used there was no exercise or postural hypotension. 5 No reduction in overall renal function attributable to labetalol was seen.
Introduction LABETALOL the first commercially available combined a- and fl-adrenoceptor-blocking agent, has been used in our unit as a hypotensive agent for the past six years. It has been administered orally and intravenously to patients with both severe and mild hypertension, in those with essential hypertension, and in those whose hypertension appeared to be related to underlying renal disease. Patient compliance is clearly improved when a single hypotensive agent is used, and in this review of 41 patients we have evaluated those situations in which labetalol was used alone. Additional data are presented which evaluated: (a) speed of onset of the oral preparation; (b) the effect of posture and exercise on the cardiovascular system; and (c) changes in overall renal function. Methods and Results
Hypotensive response to monotherapy Patient selection was entirely random, and only those who gave a history of bronchospasm either as a child or associated with an allergic or infective background were excluded. In the early stages of the study, when little was known about labetalol, the starting dose was low (50 mg four times daily). Once experience had been gained, higher initial doses were used, and it is now common to start with 100 mg four times daily. According to the hypotensive response the dose was
0306-5251/79/170129-05 $01.00
increased on an incremental basis, and the final dosage given to our group of patients ranged from 150-2,400 mg daily in divided doses. Blood pressure (BP) recordings were taken supine and standing, using a standard mercury sphygmomanometer. The pulse rate was recorded along with each BP reading. The dosage was not reduced in the presence of severe renal failure, as an earlier study had shown that the plasma half-life was not prolonged in the presence of severe renal functional impairment (Thompson et al., 1977). Of the 41 patients studied, 19 were thought to have essential hypertension, whereas the remaining 22 had underlying renal disease or urinary tract abnormalities. Labetalol alone was adequate to control BP in 12 of the 19 patients with essential hypertension (Figure 1), and 15 of the 22 patients whose hypertension was associated with renal disease also responded favourably (Figure 2). It can be seen that the reduction in systolic and diastolic BPs was not associated with any change in pulse rate. In both groups the duration of treatment ranged from 1-64 months with a dose range of 150-1,600 mg daily. Fourteen of the original 41 patients (34%) needed additional hypotensive therapy, as labetalol alone did not produce a satisfactory reduction in BP. These 14 patients were equally divided between the patients with essential hypertension and those with underlying renal disease. The results in the group with essential hypertension are shown in Figure 3. In this group two 00 Macmillan Journals Ltd 1979
130S
F.D. THOMPSON, A.M. JOEKES & M.M. HUSSEIN
190 r 180
a
b
a Systolic
170 160 c)
I
E E
80 70
150 140
130
PRE
120
L
E
60
PRE
In
a')
L
.0
110 100
200 190 180 170 160 150 0) I 140 E 130 E 120 110 100 90
90
P
PRE
L
P
NS
80 P
NS
NS
NS
Diastolic
Figure 1 BP (a; n=12; P
MONOTHERAPY WITH LABETALOL FOR HYPERTENSIVE PATIENTS WITH NORMAL AND IMPAIRED RENAL FUNCTION F.D. THOMPSON, A.M. JOEKES
&
M.M. HUSSEIN
St Peter's Group of Hospitals, and Institute of Urology, London
1 Labetalol was given to 41 hypertensive patients in a divided dosage of 150-2,400 mg daily for periods ranging from 1-64 months. 2 Monotherapy with labetalol was adequate in 12 out of 19 patients with essential hypertension and in 15 out of the 22 with renal hypertension. 3 Following a single dose of labetalol 200 mg orally a hypotensive response was seen between 1.5 and 2 hours. 4 In the doses used there was no exercise or postural hypotension. 5 No reduction in overall renal function attributable to labetalol was seen.
Introduction LABETALOL the first commercially available combined a- and fl-adrenoceptor-blocking agent, has been used in our unit as a hypotensive agent for the past six years. It has been administered orally and intravenously to patients with both severe and mild hypertension, in those with essential hypertension, and in those whose hypertension appeared to be related to underlying renal disease. Patient compliance is clearly improved when a single hypotensive agent is used, and in this review of 41 patients we have evaluated those situations in which labetalol was used alone. Additional data are presented which evaluated: (a) speed of onset of the oral preparation; (b) the effect of posture and exercise on the cardiovascular system; and (c) changes in overall renal function. Methods and Results
Hypotensive response to monotherapy Patient selection was entirely random, and only those who gave a history of bronchospasm either as a child or associated with an allergic or infective background were excluded. In the early stages of the study, when little was known about labetalol, the starting dose was low (50 mg four times daily). Once experience had been gained, higher initial doses were used, and it is now common to start with 100 mg four times daily. According to the hypotensive response the dose was
0306-5251/79/170129-05 $01.00
increased on an incremental basis, and the final dosage given to our group of patients ranged from 150-2,400 mg daily in divided doses. Blood pressure (BP) recordings were taken supine and standing, using a standard mercury sphygmomanometer. The pulse rate was recorded along with each BP reading. The dosage was not reduced in the presence of severe renal failure, as an earlier study had shown that the plasma half-life was not prolonged in the presence of severe renal functional impairment (Thompson et al., 1977). Of the 41 patients studied, 19 were thought to have essential hypertension, whereas the remaining 22 had underlying renal disease or urinary tract abnormalities. Labetalol alone was adequate to control BP in 12 of the 19 patients with essential hypertension (Figure 1), and 15 of the 22 patients whose hypertension was associated with renal disease also responded favourably (Figure 2). It can be seen that the reduction in systolic and diastolic BPs was not associated with any change in pulse rate. In both groups the duration of treatment ranged from 1-64 months with a dose range of 150-1,600 mg daily. Fourteen of the original 41 patients (34%) needed additional hypotensive therapy, as labetalol alone did not produce a satisfactory reduction in BP. These 14 patients were equally divided between the patients with essential hypertension and those with underlying renal disease. The results in the group with essential hypertension are shown in Figure 3. In this group two 00 Macmillan Journals Ltd 1979
130S
F.D. THOMPSON, A.M. JOEKES & M.M. HUSSEIN
190 r 180
a
b
a Systolic
170 160 c)
I
E E
80 70
150 140
130
PRE
120
L
E
60
PRE
In
a')
L
.0
110 100
200 190 180 170 160 150 0) I 140 E 130 E 120 110 100 90
90
P
PRE
L
P
NS
80 P
NS
NS
NS
Diastolic
Figure 1 BP (a; n=12; P
