09+O06

=PEL Core Topics - OTC=

//laxatives //

There is insufficient evidence to assess the relative effectiveness or tolerability of laxatives. Drug choice may be based on symptoms, required onset of action, patient preference, adverse effects, effectiveness of previous treatments and cost. A stepped approach can also be used. If lifestyle and dietary changes are ineffective, a bulking agent or osmotic laxative may be tried first with stimulant laxatives reserved as a second line option.

Bulking agents are useful for mild constipation, small hard stools and long term control. They are more likely to be of benefit in normal transit constipation than in slow transit constipation or anorectal dysfunction. Do not use for acute relief of constipation as they can take several days to develop their full effect. Ensure adequate fluid intake to avoid intestinal obstruction. - Glycerol can be used for rapid relief of constipation when stool is present in the lower rectum. - Lactulose and sorbitol need to be taken regularly. They are not suitable for acute relief of constipation as they can take several days to have an effect. - Polyethylene glycol laxatives also contain electrolytes to minimise electrolyte and water loss. They have a fast onset of action and are generally used for faecal impaction and severe constipation unresponsive to other treatment. - Saline laxatives contain poorly absorbed ions such as magnesium, phosphate, sulfate and citrate. They have a fast onset of action and are suitable for occasional use when rapid bowel evacuation is required. There is a risk of electrolyte disturbance particularly in the elderly, children and patients with renal impairment or cardiovascular disease. The evidence for the efficacy of stool softeners when used alone for constipation is lacking. Oral preparations may be useful to prevent straining after rectal surgery and in patients with anal fissures or haemorrhoids. They are often combined with a stimulant or osmotic laxative. Stimulant laxatives tend to be reserved for severe constipation unresponsive to bulking agents or osmotic laxatives. They are usually given at night to help produce a bowel action the following morning. Short term use is preferred although they may be used long term in spinal damage, chronic neuromuscular disease and in people taking opioids. Are used when oral laxatives are not effective or rapid relief of constipation is required. Suitable for occasional use; avoid if haemorrhoids or anal fissure are present.
 * Bulking agents **
 * Osmotic laxatives **
 * Stool softeners **
 * Stimulant laxatives **
 * Suppositories and enemas **

Resources
[|AMH - Constipation]