Drug used in constipation

Dr.Jannatul FerdoushAssistant ProfessorDepartment Of Pharmacology

• Constipation : Absence of propagating contraction in colon.

• Purgatives: They are medicine that promote defecation

largely by reducing the viscosity of the content of the lower colon.

Classification of purgatives

• Luminally active agent: 1.Bulk forming agent- Several days( at least 3 day) bran ispagula husk methylcellulose

2.Osmotic agent- inorganic salt- (with in 3 hours) magnesium hydroxide Magnesium sulfate.7H2O Lactulose

Stool (fecal) softeners( emollients)(reliefs within 1-2 days) Docusate sodium Liquid paraffin

Stimulant purgatives: Bisocodyl ( 6-10 hrs) glycerol sinna(8-12 hrs) Danthron(6-12hr)

Prokinetic agent 5HT4 agonist opioid antagonist

Enema & suppositories( 1 hrs)

M/A of Bulk & osmotic laxatives Retain water in the intestinal lumen ↓ ↑Bulk of the stool& gives pressure on the lumen ↓ Stimulate enteric nerve plexus ↓ ↑Peristalsis ↓ Evacuation of stool

• Indication: Hemorrhoids Anal fissure Diverticular disease Irritable bowel syndromeA/E: Cathertic colon Malabsorption syndrome Proteinloosing enteropathy Paralytic ileus

Osmotic laxatives

• Where a rapid bowel evacuation is required, magnesium sulphate is still used.

• This should be used in a dose before breakfast or on

an empty stomach, followed by plenty of warm fluid.

• This treatment usually causes evacuation within 2 hours

Magnesium sulphate (MgSO4) Epsom salt

• MgSO4 dissociate into Mg & SO4. This Mg draws water from intestine causing softer stool & help in evacuation

• MgSO4 is usually given in empty stomach It may cause uremia in patients with renal

insufficiency

Lactulose • It is a semi synthetic disaccharide of fructose &

galactose.

• Taken orally, it is unaffected by small intestinal disaccharidase, is not absorbed

• In the colon, bacteria convert it to its two component sugars, which are poorly absorbed; when these are fermented, the lactic acid & acetic acid are formed which function as osmotic laxatives. It takes 2-3 days to act

• Indication: – constipation, – hepatic encephalopathy

• Contraindications:– galacosaemia, – intestinal obstruction

• Side effects: flatulence, cramps, & abdominal discomfort

• Dose: expressed in terms of an eoral solution containing lactulose 3.35 g/5ml

• Constipation, adults initially 15 ml twice daily, gradually reduced according to patients needs; child under 1 year 2.5 ml, 1-5 years 5 ml., 6-12 years 10 ml twice daily, gradually reduced

• Hepatic encephalopathy, 30-50 ml 3 times daily, subsequently adjusted to produce 2-3 soft stools daily

• Avolac (solution, 3.35 mg/5ml), D-Lac (syrup), Laclose (syrup), Osmolax (syrup)

Magnesium hydroxide• Indication: mild constipation (acts in 2-4 hours)

• Caution: use only occasionally; the elderly; renal impairment; hepatic impairment

• Contraindication: intestinal obstruction

• Dose: Aqueous suspension containing about 8% hydrated magnesium oxide, 25-50ml as & when required

• Magna milk, milk of magnesia (susp 400 mg/5ml)

Fecal softner

• Decusate: Softening the stool by↓ surface tension of

stool which allows more water to remain in the feces.

It has bowel stimulant property.

↑ Intestinal fluid secretion, It mix with stool & stool become soft.

Liquid paraffin• Chemically inert mineral oil• Not digested• Tasteless• M/A:

• Lubricates the intestinal wall

• Easy & increase rate of passage of gut contents

• Reduce absorption of water in the small intestine

• Retain more water in the gut contents• Softening of the stool

• Easy evacuation

• Side effects : Anal leakage following large doses of paraffin cause

physical & social discomfort.

Granulomatous reactions caused by absorption of small quantities of liquid paraffin (especially from the emulsion)

Lipoid pneumonia (taken orally for long period, especially at night, may be aspirated & cause chronic lipoid pneumonia)

Stimulant purgatives

• Most strong laxatives

• Induces low grade inflammation in small & large intestine to promote accumulation of water & electrolyte

• Stimulate gut motility.

• Dependence:

- Stimulant empty the whole colon. But normal defecation only empties the descending colon .

-Cessation of use after a few weeks is followed by a few days constipation to collect significant materials to restore the normal state.

-This delay may convince the patient to continued need for purgatives.

• Enema: containing 130 ml of arachis oil (ground-nut

oil) would lubricate & soften impacted faeces & promote bowel movement.

• For children above 6 years, the dose has to be reduced in proportion to body-weight; not recommended for children under 6 years

Cathartic colon

• It is the anatomical and physiological changes in the colon that occurs with chronic use of stimulant laxatives.(> 3times/weeks) for 1 yr

• S/S—Bloating Feeling of fullnessAbdominal painIncomplete fecal evacuation

• Typically female patient.• Long standing H/O laxative use• Cause damage to the colonic Nerve.• Rx – surgery.