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

36
Summary and research recommendations
TABLE 6 Trials comparing laxatives in elderly patients
Bulk Calcium
polycarbophil
vs. psyllium
Bulk Stimulant Faecal Osmotic Other
softener
Stimulant Cascara +
boldo vs.
cascara +
boldo
Faecal DSS vs. DCS
softener
Osmotic Magnesium
hydroxide vs.
Laxamucil
Lactulose
vs.Agiolax
(two trials)
Other Dorbanex
vs. Laxoberal
Placebo Bran (two trials) Prucara DSS Lactulose
Psyllium Cascara
(two trials)
(two trials) (two trials) Lactitol
DSS, dioctyl sodium sulphosuccinate
DCS, dioctyl calcium sulphosuccinate
manner. As well as efficacy, studies should also
measure tolerability of treatments; information on
adverse effects (pain, nausea, bloating and flatulence)
should therefore be collected prospectively
in a standardised fashion. This research should be
undertaken soon because of the potential costsavings
to the NHS.
Conclusion
Despite their frequent use and cost to the NHS,
information on the effectiveness of laxatives in the
elderly is extremely limited. The pharmaceutical
industry has produced few new laxative products in
recent years; hence, there has been no incentive to
evaluate older remedies. Moreover, simple treatments,
such as bran, fruit and high fibre diets, are
not likely to receive the same degree of promotion
and research as more expensive pharmaceutical
products. The ‘Cinderella’ nature of the condition,
and the patients it most affects, may also be relevant.
This review has outlined those few areas
where effective treatments have been found and
highlighted the many areas of ignorance. Until
the relevant comparative trials are carried out,
it is impossible to determine which treatments are
most effective, or most cost-effective. The clear
implication of this is that there is no evidence to
support the current trend toward prescribing the
most expensive laxatives.
The existing research is equivocal on the subject
of prevention of constipation; again, further trials
are required. Many laxatives came into use before
rigorous drug studies were seen to be necessary
and so there is also little information on the
side-effects of such preparations (Kamm, 1989).
It is perhaps ironic that some of the oldest drugs
in common use should be among the least investigated,
and this must be due in part to the prosaic
nature of the condition they are used to treat. As
a result of this relative lack of research interest,
a significant amount of work of good methodological
quality is required in this area. While this
would finally answer questions about the relative
effectiveness of different treatments, it would also
permit a cost-effective management strategy for
constipation to be defined. Until that research is
available, it is unclear what exactly constitutes the
‘best-buy for constipation’ in older people and,
moreover, there is currently no evidence to suggest
that this is represented by the danthron laxatives.