• PPIs reduce the effectiveness of clopidogrel in preventing the recurrence of adverse cardiac events such as heart attack and coronary artery restenosis

Drugs increasing mucosal resistance

• Physical barriers
• Bismuth
• Sucralfate
• Prostaglandin analogues
• Misoprostol

Antacids

• Increase rate of emptying => Short effect
• Stimulate gastrin release => Tolerance/adaptation

H. pylori eradication

• Must have a PPI
• Plus any two of:
• Amoxicillin
• Metronidazole
• Clarythromycin
• Doses vary depending on combination
• Choose the ones patient hasn't taken recently

Management of constipation

• Contraindications
• Intestinal perforation or obstruction
• Bulk-forming
• Fybogel, Methylcellulose
• Stimulants (NB abdo. cramps)
  
• Anthraquinones
• Senna
• Co-danthramer (palliative only - ?carcinogenic)
• Docusate sodium (dual effect)
• Diphenylmethabe derivatives
• Softeners (NB risk of incontinence)
  
• Docusate sodium
• Liquid parafin
• Osmotic
• Lactulose
• PEG (Movicol)
• Magnesium salts
• Phosphate

Diarrhoea

• Drug causes
• Magnesium-containing antacids
• NSAIDs
• Lithium
• PPIs
• Treatment
• Rehydration fluids MUST CONTAIN GLUCOSE for salt uptake
• Generally no Abx
• C. diff
• Treat with oral metronidazole or vancomycin
• Antimotility drugs
  
• NEVER in anyone <12

Nausea + vomiting pathways

• Chemoreceptor trigger zone
  
• Dopamine + 5-HT3 serotonin receptor
  
• Vestibular
• Cholinergic muscarinic receptor 
• Vomiting centre pathways
• Histamine + cholinergic muscarinic receptors
  
• Gastric status
• Dopamine + 5-HT4 serotonin receptor

Antiemetics

• Metoclopramide
• Dopamine D2 antagnoist
• => Causes dystonia, esp. if <18 or >70
• Can treat with procyclidine (anticholinergic)
  
• Promethazine
• 1st generation antihistamine
• Safe in pregnancy (e.g. hyperemesis gravidarum)
• Sedative effects
  

• Yes
• Azathioprine
• Infliximab
• Methotrexate
• No
• Aminosalicilates (but probably not harmful so often continued)
• Cyclosporin (high risk of adverse events)
• Corticosteroids (harm > benefit)
  

• Metronidazole tastes bad
• Beware antimotility drugs in UC
  
• => Paralytic ileus + megacolon