Effectiveness of Laxatives in the Elderly - NIHR Health Technology ...

TABLE 5 contd Summary of RCTs of prevention and treatment of constipation in the elderly
Ewerth et al, 1980; Vanderdonckt et al, 1990)
do not present enough information (SDs or
standard errors) to allow calculation of confidence
intervals and, for these cases, the point
estimate is plotted, together with an indication
of significance.
It can be seen from Figure 4 that two trials
reported a significant increase in bowel movements
per week compared with placebo. Marchesi
(1982) found a stimulant laxative containing
cascara to produce a mean increase of 2.6 bowel
movements per week, and Vanderdonckt and
colleagues (1990) found an increase with an
osmotic laxative (lactitol) of 1.9 bowel
movements per week.
Non-significant benefits of fibre are shown
in two trials (Cheskin et al, 1995; Rajala et al,
1988); however, the fibre mixture used as a
laxative in the trial by Rajala and colleagues
was sweetened with lactitol, which has an
osmotic laxative effect and, hence, any benefit
may not be due solely to the fibre. Two trials
found statistically non-significant trends in
favour of a faecal softener (Hyland & Foran,
Health Technology Assessment 1997; Vol. 1: No. 13
Study Class of Study Trial Results: Comments
(country) laxative population, description, bowel movements (methodological
sample size follow-up per week, and score)
other outcomes
continued
Treatment of constipation – RCTs directly comparing laxatives
Doffoel et al, Osmotic vs. Nursing-home Treatment 1: Lactitol, 5.5 vs. 4.9 (p = 0.0001). Drop-outs = 3%
1990 osmotic patients 15 g/day Stools more often of (4)
(France) n = 60 Treatment 2: normal consistency
Mean age 79 years Lactulose, 15 ml/day with lactulose (NS)
(665 g/l) increased
as necessary
2 weeks
Lederle et al, Osmotic vs. Nursing-home Treatment 1: 7.0 vs. 6.7 (p < 0.05). Double-blind
1990 osmotic patients Lactulose, 30 ml No significant group (described)
(USA) n = 31 Treatment 2: differences in overall Drop-outs = 3%
Mean age 72 years Sorbitol, 30 ml symptoms or need (6)
4 weeks for other laxatives
Agiolax ® = Plantaginis ovata, 2.6 g, + isphagula, 0.11 g, + senna, 0.62 g
Lunelax ® = Ispaghula, 3.3 g, + senna, 25 mg
Laxamucil ® = Plantain, 800 mg/g, + sorbitol, 190 mg/g
Dorbanex ® = Danthron + poloxalkol
Golytely ® = Sodium, 125 mmol/l, + potassium, 10 mmol/l, + sulphate, 80 mmol/l, + bicarbonate, 20 mmol/l, + polyethylene glycol, 80 mmol/l
Boldo = Chilean bark extract (folk remedy)
DCS, dioctyl calcium sulphosuccinate; DSS, dioctyl sodium sulphosuccinate; NS, not significant
1968) and an osmotic laxative (Sanders, 1978).
It can also be seen from Table 5 that all the
trials identified involved very small patient
numbers and it is therefore possible that those
trials in which non-significant results were
found lacked enough power to detect any
significant differences.
One other trial (Finlay, 1988) assessed bowel
movement frequency, but not actual numbers of
bowel movements. In this study, supplementary
bran was found to have no statistically significant
effect on the number of days on which bowel
movements occurred.
Other outcomes: consistency, pain,
laxative use
Stool consistency was measured in six trials
of single agents. The methods used to assess
consistency varied between trials. Passmore
and colleagues (1993a; b), for example, used
a 6-point scale ranging from 0 (‘no bowel movement’)
to 5 (‘loose’), while Kinnunen and
colleagues (1993) used a 3-point scale (‘hard’,
‘normal’, or ‘watery’). Quantitative data on
consistency was not therefore pooled. The
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