GI: ANTIMOTILITY DRUGS

Question 1

ANTIMOTILITY: INDICATIONS

Answer 1

• Diarrhoea (in context of IBS or Viral GE)

Question 2

ANTIMOTILITY: MOA

Answer 2

• Agonist of the OPIOID U-RECEPTORS in the GI tract
• Increases non-propulsive contractions of the gut smooth muscle but reduces propulsive (peristaltic) contractions
• Transit of bowel contents is slowed and anal sphincter tone is increased
• Slower gut transit allows for more time for water absorption = Hardens stools more effectively

Question 3

ANTIMOTILITY: ADVERSE EFFECTS

Answer 3

• GI effects (predictable from the MOA i.e abdo cramping, constipation, flatulence)
• Indirectly = inappropriate inhibition of peristalsis
• CNS penetrating OPIOIDS are used (eg CODEINE PHOSPHATE) = OPIOID TOXICITY

Question 4

ANTIMOTILITY: WARNINGS

Answer 4

• Loperamide should be avoided in ACUTE ULCERATIVE COLITIS (inhibtion of peristalsis may increase the risk of megacolon and perforation)
• C.Difficile Colitis - including patients who develop diarrhoea in association with broad spec antibiotics
• Acute bloody diarrhoea patients should not use it
• Certain strains of E.Coli = HAEMOLYTIC URAEMIC SYNDROME can develop ( increased risk when antimotility drugs are used)

Question 5

ANTIMOTILITY: INTERACTIONS

Answer 5

None

Question 6

ANTIMOTILITY: EXAMPLES

Answer 6

• LOPERAMIDE

- CODEINE PHOSPHATE