Cathartic, laxative and purgative are terms describing drugs that promote evacuation of the intestine; the difference between the terms is largely one of degree. Cathartic and purgative are interchangeable terms describing drugs that promote rapid evaluation of the intestine and noticeable alteration of stool consistency. The evacuant action of a laxative is less pronounced, but large doses of a laxative may produce catharsis or purgation. Cathartic, laxative and purgative drugs will be referred to as laxatives.
Laxatives available at health center level are usually subdivided into several categories including the bulk forming laxatives such as cellulose derivatives, psyllium preparations; stimulant laxatives (contact laxatives) include antraquinone-containing agents such as senna & cascara, diphenylmethane derivatives such as bisacodyl and also other miscellaneous agent such as castor oil, osmotic laxatives such as Glycerin, and the lubricant laxative liquid paraffin.
Bulk forming laxatives which relieve constipation by increasing faecal mass and stimulating peristalsis; the full effect may take some days to develop and patients should be told this. They are of particular value in those with small hard stools, but should not be required unless fiber cannot be increased in the diet. They are useful in the management of patients with colostomy, ileostomy, haemarrhoids and fissure, chronic diarrhoea associated with diverticular disease, irritable bowel syndrome and as adjuncts in ulcerative colitis. Adequate fluid intake must be maintained to avoid intestinal obstruction. Unprocessed wheat bran taken with food or fruit juice, is a most effective bulk forming preparation.
Stimulant laxatives which increase intestinal motility and often cause abdominal cramp; they should be avoided in intestinal obstruction. Prolonged use of stimulant laxatives can precipitate the onset of an atonic non-functioning colon and hypokalaemia; however, prolonged use may be justifiable in some circumstances. Glycerin suppositories act as a rectal stimulant by virtue of the mildly irritant action of glycerin. Powerful stimulants such as cascara and castor oil are obsolete.
Faecal softeners such as liquid paraffin, which is the classical lubricant, lubricate and soften impacted faeces.
Osmotic laxatives act by retaining fluid in the bowel by osmosis or by changing the pattern of water distribution in the faeces.
Tablet, 5 mg
Suppository 5 mg, 10 mg
Indications: - constipation and for bowel evacuation.
Cautions: -care should be taken in patients with inflammatory bowel disease, the suppositories should be used with caution in patients with rectal fissures or ulcerated haemorrhoids; it should be preferably avoided in children. See also notes above.
Side effects: - see notes above; and abdominal discomfort (such as colic or cramp); gripping (tablets); local irritation (suppositories).
Contraindications: -appendicitis, rectal bleeding, congestive heart failure, hypertension, diabetes mellitus, intestinal obstruction or undiagnosed abdominal symptoms; see also notes above
Dose and Administration:
Oral: Adults and children (>12 years) - 1-3 tablets daily as a single dose. Children (> 3 years) - 1-2 tablets or 0.3 mg/kg daily as a single dose.
Rectal: Adults and children (>12 years) - 10mg daily as a single dose. Children 2-11 years, 5-10mg daily given as a single dose. Children (< 2 years of age) 5mg daily as a single dose.
Note: - It is usually effective within 6 to 12 hours following oral administration and within 15 to 60 minutes following rectal administration.
- Oral bisacodyl should be administered the evening before a morning bowl-movement is desired.
-Swallow the enteric-coated bisacodyl whole and not crushed to avoid gastric irritation.
-Take each dose with a full glass of water or other liquid.
-Rectal bisacodyl suppositories and enemas may be administered at the time a bowl movement is desired.
Storage: -store at room temperature in a well-closed container.
Tablet, 125 mg
Indications - constipation
Cautions: -care should be taken in patients with inflammatory bowel disease prolonged use should be avoided, it should be preferably avoided in children; see also notes above.
Side effects: see notes above; and mild abdominal discomfort, diarrhoea (prolonged use), reversible melanosis coli, the urine may be coloured yellowish brown or red.
Contraindications: - see notes under bisacodyl
Dose and Administrations:-Orally
Adults and children (10 years and over) - 0.3 - 1g, usually at bedtime. A laxative effect usually occur 6 to 8 hours after administration. As discussed above such laxatives have a limited role in the management of constipation.
Storage: -at room temperature, in airtight container. Protect from light.
Tablet (total sennosides), 7.5 mg
Indication: -constipation and bowel evacuation,
Cautions, Contraindications - see under cascara sagrada
Dose and Administrations
Adult, orally, 15 - 30 mg, as a single dose at bedtime. Children (over 6 years of age), one half of the adult dose, and those aged 2 to 6 years are quarter the adult dose.
Note: - It is usually effective with in 6 to 12 hours.
Storage: - at room temperature in a dry place. Protect from freezing
Indications: to facilitate defecation in geriatric patients with diminished colonic motor response; constipation occurring secondary to idiopathic slowing of transit time, to constipating drugs or to irritable bowel or spastic colon syndrome; neurologic constipation and to empty the bowel prior to surgery or radiologic proctoscopic or sigmoidoscopic procedure.
Cautions: - avoid prolonged use, and use in children up to six years of age; elderly patient.
Drug interactions: potassium sparing diuretics, potassium supplements.
Side effects: - abdominal discomfort, nausea, mild cramp, gripping or faintness, excessive irritation of the colon, violent purgation.
Contraindications: - pregnancy, acute abdominal pain, nausea, vomiting or other symptoms of appendicitis or undiagnosed abdominal pain, intestinal obstruction.
Dose and administation: - Orally,
Constipation, Adult, 15 ml daily; Child (< 2 years) - 1-5 ml daily, (> 2 years)- 5 - 15 ml daily.
For total colonic evacuation prior to surgery or radiologic sigmoidoscopic or procopic procedure administered as a single dose about 16 hours before the procedures.
Adults and children (>=12 years): 15 - 60 ml; Children - 2 - 11 years: 5 -15 ml; (< 2 years): 1 - 5 ml.
Note: - Drink increased fluid. Take each dose with a full glass of water or other liquid.
Storage: -at room temperature in a tight container and in dry place. Protect from freezing
Suppository, 1 g, 1.346 g, 2 g, 2.76 g
Indications: -constipation, especially in children.
Cautions: -avoid habitual use.
Side effects: -rectal discomfort such as irritation, burning and pain may occur rarely.
Dose and Administration: Rectally.
The suppositories should be moistened with water before insertion. Adults: 2 - 4g suppository. Children: 2g suppository. Infants: 1g suppository.
Storage: -in a cool place, in airtight containers.
Liquid parafin, Heavy
Indication: -constipation associated with stricture of colon.
Cautions: - avoid prolonged use and caution should be taken in children, pregnant women, elderly patients.
Note: should not be taken immediately before going to bed.
Drug interactions: - avoid concomitant administration of the oil with fat soluble vitamins (A, D, E, K), carotene, oral contraceptive, cumarine and indandione derivative anticoagulants.
Contraindications: - acute abdominal pain, nausea, vomiting or other symptoms of appendicitis or undiagnosed abdominal pain. Also contraindicated in children younger than 3 years old.
Side effects: - seepage of mineral oil that may cause soiling of the skin and clothing, anal irritation, pruritis, impair normal rectal reflex mechanism, granulomatous reaction caused by absorption of small quantities of liquid paraffin, lipoid pneumonia.
Dose and Administration - orally, 5-20ml, when required.
Storage - at room temperature and protect from freezing.
Indications: - constipation that occurs following bed rest or hospitalization.
Cautions: - avoid prolonged use. Adequate fluid should be taken to avoid intestinal obstruction.
Drug interactions: - anticoagulants, digitalis glycosides, and salicylates.
Contraindications: - appendicitis, rectal bleeding, congestive heart failure, intestinal obstruction, esophageal obstruction (dysphagia).
Side effects: - allergies to some vegetable components (difficulty in breathing, skin rash or itching), esophageal blockage or intestinal impaction.
Dose and Administration - Orally, Adults and children - 12 years and older - 30gm given daily in divided doses of 2.5 - 7.5gm per dose; Children 6-11 years old - 15gm daily given in divided doses of 2.5-3.75gm per dose.
Storage: - at room temperature in a tight container and in a dry place.