1. Management of Acute Diarrhea

2. What is Diarrh(o)ea?
Diarrhoea is a symptom characterized by an abnormal increase in stool frequency (more than 3 times daily) or liquidity (> 80% water);
The normal frequency of bowel movements varies with each individual
< 14 days: acute; 14 days-4 months: persistent; > 4 months: chronic diarrhea
Only acute diarrhea can be treated by OTC

3. Causes:
bacterial or viral infection through ingestion of contaminated food or drink;
E.Coli, S.aureus  toxins  mucosal cells hypersecretion of fluid watery diarrhoea with little or no fever or other symptoms;

4. Causes:
Invasive E. coli, Salmonella and Shigella: directly invade mucosal epithelial cells and cause an inflammatory reaction less fluid diarrhea accompanied by nausea, vomiting, cramps and sometimes low-grade fever

5. Causes:
Viral infections, which often affect babies and young children, also produce watery diarrhoea
Non-infective causes: stress, alcohol, and hot spicy food
Drugs: antibiotics “all but varying degrees”. Depends on extent that drug disrupts normal intestinal microflora. Other: laxatives, misoprostol. Olsalazine, anticancer, antihypertensive agents

7. Consequences Normal faeces contain 60-85 % water
Water loss during defecation= mL/day
In diarrhoea: water loss 4X normal K and Na loss fall in plasma pH (acidosis) serious metabolic consequences
Fluid & electrolyte losses are increased if vomiting also occurs

8. Consequences
In babies/children: hazardous as high proportion of total body weight is lost and dehydration can occur very rapidly
Elderly are also particularly sensitive to the effects of fluid and electrolytes loss, especially if on diuretics
Reduction in blood volume + RAS  + aldosterone (1) loss of K (hypokalemia)
(2) Excessive fluid loss reduction of renal artery flow renal failure

9. When to Refer? If diarrhoea lasts more than:
72 hours : adults and older children
48 hours : children < 3 years old & elderly
24 hours in children < 1 year old
Refer immediately in infants under 3 months old

10. Medical evaluation is needed for:

12. Treatment Oral rehydration therapy (ORT) Opioids Adsorbents
Dietary management
In UK: belladonna extract

14. Self-care of acute diarrhea in children aged 6 mo to 5 yrs

16. Self-care of acute diarrhea in children > 5 yrs, adolescents & adults

18. Oral rehydration therapy (ORT)
First line treatment of acute diarrhoea
the very young & elderly (particularly important)
ORT not intended to relieve symptoms
Use of antidiarrheals (antimotility drugs or adorbents) is regarded unnecessary and sometimes undesirable
Use of antidiarrheals (for comfort/convenience) is used as adjunct to ORT

19. Oral rehydration therapy (ORT)
Mode of action:
replace water and electrolytes lost through diarrhea and vomiting;
K & Na: replace ions
citrate and/or bicarbonate: correct acidosis
glucose: carrier for Na ions and hence water across the mucosa of the small intestine

20. Oral rehydration therapy (ORT)
ORT is not intended to stop diarrhoea, but acute diarrhoea is self-limiting and normally ceases within hours;
ORT can be recommended for patients of any age, even when referral to a doctor is considered necessary

23. Dose & Administration of ORS
the content of 1 sachet or 2 effervescent tablets should be dissolved in ml of water (freshly boiled and cooled in case of infants)
discard unused solution 1 hr after reconstitution or no longer than 24 hrs (if refrigerated)
Dose in adults: ml after every loose motion, or 2-4 L over 4-6 hrs

24. Dose & Administration of ORS
Patients may prefer to sip 1-2 tsp every few minutes rather than drink large quantities less frequently
children > 2 yrs: cupful (200ml) after every loose stool
children < 2 yrs: ¼- ½ cupful
Infants: normal feed volume
Both breast and bottle-fed babies should continue to be fed normally (without dilution)

25. Contraindications & cautions
No contraindications to ORS unless the patient is vomiting frequently  IV fluid and electrolyte replacement;
fluid overload from excessive administration of ORS is highly unlikely unless continued for babies and young children > 48 hrs (recognized by puffy eyelids)  rapidly withhold ORS and other liquids

26. Homework
The place of household oral solutions in rehydration

27. Opioids Loperamide Mode of action:
increase tone of both small and large bowel and reduce intestinal motility (enhances fluid and electrolyte reabsorption);
increase the sphincter tone and decrease secretory activity along GIT

28. Loperamide
It is a synthetic opioid agonist that has a high affinity for, and exerts a direct action on  opiate receptors in the gut wall;
also has a high first-pass metabolism so very little reaches the systemic circulation;
effective in reducing the duration of diarrhea (25 vs 40 hrs with placebo)

29. Loperamide
50 fold more potent than morphine and 2-3 times more potent than diphenoxylate in its effect on GI motility, but penetrates the CNS poorly, thus has lower risk of CNS side effects;
Other mechanisms: disruption of cholinergic and non-cholinergic mechanisms of peristalsis, inhibition of calmodulin function and inhibition of voltage dependent Ca channels

30. Loperamide Indications: traveller’s diarrhoea
non-specific acute diarrhoea
chronic diarrhoea associated with inflammatory bowel disease
AAP does not recommend use in children < 6 years old
Used when patient is afebrile or have mild fever and does not have bloody stool

31. Loperamide Dosage & Administration
dosage forms: caplets (2 mg), and liquid (1 mg/5ml)
Dose: 4 mg initially, then 2 mg after each loose stool/ Do not exceed 16 mg/day
Consult product instructions for pediatric dose

32. Loperamide Side effects:
At usual doses: few side effects other than occasional dizziness and constipation
Other: abdominal pain and distension, nausea, vomiting, dry mouth, fatigue and hypersensitivity reactions
It may worsen effects of invasive bacterial infections and may cause toxic megacolon in antibiotic-induced diarrhoea
If abdominal distension, constipation, or ileus occurs, loperamide should be discontinued

33. Loperamide Contraindication
Loperamide should not be used in patients with fecal leukocytes, high fever, or blood or mucus in the stool (dysentery);
Loperamide may cause paralytic ileus in patients with dysentery
Paralytic ileus: paralysis or inactivity of the intestine that prohibits the passage of material within the intestine. May be a result of anticholinergic drugs, injury or surgery

34. BSS
BSS (Bismuth subsalicylate): claimed to pocess adsorbent properties; large doses are required and salicylate absorption may occur (be cautious!). Not labeled for children < 12 yrs
HW:
toxicity of BSS
Drug interactions with BSS

35. Adsorbents Mode of action:
adsorb the microbial toxins and micro-organisms to their own surfaces
drugs not absorbed from the GIT toxins and MOs are excreted in stool;
Hydrophilic adsorbents (e.g. pectin and bulk-forming agents; ispaguala, methylcellulose, and sterculia), bind water within the intestine causing watery stool to become more formed

36. Adsorbents
the main constituents in the antidiarrhoeal preparations for young children (whom opiates and antimuscarinics are contraindicated);
not absorbed from GIT harmless and safe to use
Debate: reduce evacuation of faeces- prolong presence of pathogens/toxins in bowel. Adsorption: non-specific process (medicines)

40. Dietary Management
Traditionally: withdrawal of feedings, initiation of clear liquids, with a slow reintroduction of feedings over several days
However, oral intake does not worsen diarrhoea, clinically significant nutrient malabsorption is uncommon (80-95% CHO, 70% of fat and 75% of the nitrogen from protein) in acute diarrhoea and bowel rest is generally not necessary

41. Dietary Management
Early refeeding in combination with maintenance ORS therapy, improves outcomes of acute diarrhoea in children by reducing the duration of diarrhoea, reducing stool output and improving weight gain

42. What foods are best for refeeding?
most infants and children with diarheoa can tolerate full-strength breasts milk and cow’s milk;
The familiar BRAT (bananas, rice, apple sauce and toast) is frequently prescribed- insufficient calories, protein and fat especially in strict or prolonged use and is not recommended by AAP

43. What foods are best for refeeding?
Diet should include:
complex carbohydrate-rich foods (e.g. rice, potatoes, bread, cereals)
Yogurt
lean meats
Fruits and vegetables

44. What foods are best for refeeding?
Avoid:
fatty foods
foods rich in simple sugars that may cause osmotic diarrhoea
spicy foods that may cause GI upset
Caffeine (WHY??)