1. 1Dr Anuj

2.  Laxatives are used
1) To treat constipation
2) To avoid undue straining at defecation
3) Before or after any anorectal surgery
4) In bedridden patients
Laxatives have mild activity and are usually stool
softeners.
2Dr Anuj

3.  Purgatives are used for complete colonic cleansing
prior to GI endoscopic procedures, pre-post MI
bed ridden patients , also to prepare bowel before
surgery or abdominal X-ray, may be needed for
neurologically impaired patients.
 Purgative either provide semisolid stool or lead to
watery evacuation
 In low doses these can be used as laxative also
3Dr Anuj

4. CLASSIFICATION
1. Bulk forming:- Dietary fibre : Bran Psyllium, Ispaghula
2. Stool softener :- Docusates (DOSS), Liquid paraffin
3. Stimulant purgative
a) Diphenylmethanes:- Phenolphthalein, Bisacodyl
b) Anthraquinones(Emodins) :- Senna, Cascara sargada
c) 5HT4 agonist:- Prucalopride
d) Fixed oil :- Castor oil
5. Osmotic purgatives :-
Magnesium salts : sulfate , hydroxide
Sodium salts: sulfate phaophate
Sod. Pot. Tartrate
Lactulose
4Dr Anuj

5. Bulk forming
 Luminally active, hydrophilic indigestible vegetable fibres
 Stimulates peristalsis and defecation reflexes by increasing
faecal bulk
 Adequate water must be taken with all Bulk forming agents
 Effect appears within 1-3 days
 S/E Bloating and flatus causing abdominal discomfort
5Dr Anuj

6. Stool softener : Docussates(Dioctyl sodium sulfosuccinate)
 Also known as surfactant laxatives
 Luminally active agents , an anionic surfactant , softens
stool by decreasing surface tension of fluids in the bowel.
 100-400 mg oral per day in divided doses
 Indicated when straining at defecation is avoided
 Latency period 1-3 day
 Bitter in taste can cause nausea
 Cramps and abdominal pain may occur
 Hepatotoxicity may occur after prolonged use
 Increases absorption of liquid paraffin , hence should not
be given together
6Dr Anuj

7. Stimulant purgative
 Stimulate peristalsis by irritant action on intestinal mucosa
 Also stimulate colonic electrolyte and fluid secretion by altering
absorptive and secretory activity of mucosal cells.
 Inhibit Na+ K+ ATPase at the bosolateral membrane of villous
cells
 Secretion is enhanced by activation of cAMP in crypt cells as well
as by increasing PG synthesis
 Laxative action of bisacodyl and cascara is dependent upon NO
synthesis/action in colon
 Larger dose of stimulant purgative can lead to purgation
resulting in fluid and electrolyte imbalance, hypokalemia.
 Regular and long term use – colonic atony
 Can reflexly stimulate gravid uterus- C/I in Pregnancy
 Oter C/I- Subacute or Chronic intestinal obstruction
7Dr Anuj

8. Bisacodyl: (DULCOLAX 5 mg)
 Partly absorbed and reexcreted in bile.
 Activated in intestine by deacetylation.
 Primary site of action is colon- Irritate mucosa,
produce inflammation & increase secretion
 Effect appears within 6-8 hrs.
8Dr Anuj

9. Anthraquinones: Senna, Cascara sargada
 Senna : Leaves and pods of Cassia spp.
 Cascara sargada: bark of buck thorne tree
 Degraded by colonic bacteria to liberate anthrol form
which either acts locally or absorbed into circulation and
excreted in bile to act on small intestine
 Takes 6-8 hrs to produce action
 Active principle of these drugs act on myenteric plexus to
increase peristalsis and decrease segmentation
 Senna has been found to stimulate PGE2 secretion in rats
9Dr Anuj

10.  Prucalopride :- selective 5HT4 receptor agonist
for tt of chronic constipation in women
 Tegaserod :- 5HT4 receptor partial agonist ,
 Used for tt of constipation predominant IBS
Withdrawn from market due to cardiovascular risk
 Lubiprostone: PG analogue, activates Chloride channel in
small intestine to promote intestinal secretions and
motility
 used for tt of constipation predominant IBS
10Dr Anuj

11. Osmotic purgatives
 These are soluble inprganic salts , that increases the faecal
bulk by retaining water osmotically and distend the bowel
increasing peristalsis indirectly.
 Act on small as well as large intestine
 Magnesium salts release Cholecystokinin which further
helps in increasing intestinal secretions and peristalsis.
 Milk of Magnesia is most commonly used , other salts have
an unpleasant taste
 30 ml of its 8% w/w suspension is given in morning, effects
comes within 2-3 hrs.
11Dr Anuj

12.  Usually preferred for bowel preparation before surgery,
colonoscopy, in food/drug poisoning and as after purge in
tt of tapeworm infestation
 Should not be used for prolonged period in pt with renal
insufficiency due to risk of hypermagnesaemia.
12Dr Anuj

13. Lactulose(DUPHALAC 10gm/15ml syp)
 Semisynthetic disaccharide of fructose and lactose, neither
digested nor absorbed in small intestine-retains water
 Broken down in the colon by bacteria to osmotically more
active product
 Produces soft, formed stool in 1-3 days.
 Flatulence and flatus is common , cramps occur in
few,some pt may feel nauseated due to peculiar sweet taste
 Also used for tt of hepatic encephalopathy in dose of 20gm
TDS orally
 Lactulose is degraded to lactic acid and converts NH3 to
ionised NH4+ salts which is then excreted.
13Dr Anuj

14. Questions
 Active principle of these drug act on myenteric plexus
 Anthraquinones (Senna & cascara sargada)
 Lactulose is used in tt of
 Hepatic encephalopathy
 It turns urine pink if alkaline
 Phenolphthalein
 Cholecystokinin is release by
 Magnesium salts
14Dr Anuj

15.  Alvimopan
peripherally acting μ opioid receptor antagonist for the
tt of postoperative ileus and constipation after surgery
15Dr Anuj

16. TREATMENT OF DIARRHOEAS
 Too frequent, often too precipitate passage of poorly
formed stool
 WHO “ 3 or more loose or watery stools in a 24 hr
period”
 Cause
 ↓ed electrolyte and water absorption
 ↑ed secretion by intestinal mucosa
 ↑ed luminal osmotic load
 Inflmm of mucosa & exudation into lumen
16Dr Anuj

17. 1. Treatmrnt of fluid depletion, shock and acidosis
2. Maintainance of Nutrition
3. Drug therapy
 Oral rehydration if fluid loss is mild 5-7%BW
 IV rehydration only when fluid loss is > 10% of BW
 Dhaka fluid
 NaCl -85 mM=5gm
 KCl- 13mM=1gm,
 NaHCO3 48mM =4gm in 1 ltr of water
17Dr Anuj

18.  New formula WHO-ORS
 NaCl: 2.6g
 KCl: 1.5g
 Trisod. Citrate : 2.9 g
 Glucose : 13.5 g
 Water : 1 L
Total osmolarity 245 mOsm/L
 Zinc in pediatric diarrhea
 Maintainance of nutrition
18Dr Anuj

19. Drug Therapy
1. Special antimicrobial drug
2. Probiotics
3. Drugs for Inflammatory bowel disease
4. Nonspecific antidiarrhoeal drug
19Dr Anuj

20.  antimicrobial drug are of no value in diarrhoea due to
noninfectious causes
1. IBS
2. Coeliac disease
3. Pancreatic enzyme deficiency
4. Tropical Sprue
5. Thyrotoxicosis
20Dr Anuj

21.  antimicrobial drug are useful in severe cases of
1. Travellers diarrhoea :- Cotrim, Norflox, Doxy, Rifaximin
2. EPEC :- Cotrim, FQ
3. Shigella enteritis :- Cipro norflox
4. Nontyphoid salmonella :- FQ Cotrim
5. Yersinia :- Cotrim Cipro
 Antimicrobial drug are regularly useful in
1. Cholera :- Fluid replcement, Tetracyclin, Cotrim,
2. C. jejuni:- Norflox and other FQ
3. Clostridium difficile:- Metronidazole, Vancomicin
4. Amoebiasis, giardiasis :- Metron , Dilox furoate
21Dr Anuj

22. •Drugs for IBD(Inflammatory bowel disease)
 chronic relapsing inflammatory disease of ileum colon or both a/w
systemic manifestation
Drugs used can be grouped in
 5-ASA compounds
 Corticosteroids
 Immunosuppressants
 TNF-α inhibitors
A. Ulcerative colitis:- Aminosalicylates(sulfasalazine),glucocorticoids,
cyclosporine,azathioprine , 6-mercaptopurine
B. Crohn’s disease :-
AntiTNF-α drugs( Infliximab adalimumab, Certolizumab),
Methotrexate, Antibiotics( metron cipro), Anti integrin monoclonal
antibody (Natalizumab)
22Dr Anuj

23.  5-ASA compounds( Sulfasalazine)
Azo bond split by colonic bacteria to release 5-ASA & sulfapyridine
5-ASA :- exerts antiinflammatory effect
sulfapyridine :- serves to carry 5-ASA to colon without being
absorbed proximally.
 Mesalazine
 Olsalazine
 Balsalazide
 Corticosteroid :- 40-60 mg/day
 Immunosoppressant :- Azathioprine (purine antimetabolite)
Methotrexate(DHFRase inhibitor)
Cyclosporine
TNF-α inhibitors :- Infliximab
23Dr Anuj

24. Nonspecific antidiarrhoeal drugs
1. Antisecretory drugs
2. Antimotility drugs
24Dr Anuj

25. Antisecretory drugs
 Racecadotril:- (Thiorphan)Enkephalinase inhibitor
↓ intestinal hypersecretion without affecting motility
lowers mucosal cAMP due to enhanced ENK action
indicated in short term treatment of acute secretary diarrhoea
(REDOTIL 100 mg cap)
 Bismuth subsalicylate
 Anticholinergics
 Octreotide
 Opioids
α2 adrenergic receptor agonist :- clonidine
25Dr Anuj

26. Antimotility drugs
 Opioid drugs which increase small bowel tone and
segmenting activity,
 ↓ propulsive movements,
 ↓ intestinal secretions ,
 enhancing absorptions
 Diphenoxylate (2.5mg) + atropine(0.025mg):- LOMOTIL
 Loperamide
opiate analogue with major peripheral μ opioid and weak additional
anticholinergic property
26Dr Anuj

27. Probiotics in Diarrhoea : (ECONORM,
BIFILAC, ENTEROGERMINA)
27Dr Anuj

28.  Drug used for tt of dirrhoea in diabetic pt
 Clonidine
 Drug used to treat secretary diarrhoea
 Octreotide
 Variceal blleeding can be controlled by
 Octreotide
 Alosetron ,a drug useful in pt of Irritable bowel
syndrome with diarrhea acts through
 5-HT3 receptor antagonist
 An effective antidiarrhoeal agent that inhibits
peristalsis movt
 Diphenoxylate
28Dr Anuj