Gastrointestinal Disorders Flashcards
Osmotic laxatives work by…
Increasing the water content in the stool
Explain the physiology that creates stomach acid.
The mucosal lining of the stomach contains Parietal cells.
The parietal cells can be stimulated by two neurotransmitters (Histamine or Acetylcholine) or a Hormone (Gastrin). These all have teir own receptors on the outside of the cell.
Stimulating the cells begins to pump out positively charged hydrogen ions (H+) into the stomach via the proton pump.
The negatively charged Cloride ions (Cl-) follow the H+, but leave the cell via their own chloride channel.
Once in the stomach, the H+ and Cl- ions combine to create HCl (hydrochloric acid) when it can begin to break down food in the stomach.
Philipa tells you on the morning medication round that she needs to have her lanzoprazole to “line her stomach”. Is this an accurate statement from Philipa?
Not quite.
Lanzoprazole is a Proton Pump Inhibitor (PPI) which reduces the amount of stomach acid being produced by preventing the parietal cells from moving hydrogen into the stomach to create acid.
Medications like NSAIDS can cause damage to the stomach lining (ulcers) that is worsened by the presence of too much stomach acid.
PPIs decreases stomach acid production which promotes the healing of gastric and duodenal ulcers and other inflamed gastrointestinal tissue areas.
True or False:
PPI can be bought over the counter.
True.
PPI in the form of esomeprazole is available over the counter at a reduced dose of 20mg.
Name two PPI medications.
Lanzoprazole
Omeprazole
Esomeprazole (OTC and prescription)
What are the pharmacodynamic effects of Omeprazole?
The proton pump within the parietal cell moves Hydrogen into the stomach, and Cloride follows where they combine to create hydrochloric acid.
A PPI like Omeprazole inhibits the proton pump, preventing Hydrogen ions from entering the stomach.
Less hydrogen leads to less Chloride leads to less stomach acid production.
What is GORD?
Gastro-oesophageal reflux disease.
Where gastric acid from the stomach is refluxed up into the oesphagus causing irritation of the internal mucosal lining of the oesophagus.
What are some of the short term effects or symptoms of GORD?
Pain (heartburn)
Hoarse voice
Difficulty lying flat
Cough
Aspiration (fluid into lungs).
What are some of the long term effects of GORD?
Scarring
Stricture (tightening of oesphagus)
Barrets oesphagus (pre-cancerous)
Increased risk of cancer
Ulcerations
Infections
Thinking along the lines of medication management, what should you consider when giving medications to a patient with GORD?
GORD increases the Ph of the gastric contents, which might inhibit the breakdown of some medications.
What are some of the physical assessment that should be carried out for a patient with GORD?
Onset/Duration
Pain on swallowing - due to ulcer or stricture
Assess BMI - due to increased internal pressure that obesity creates.
Dental erosion - coming up far enough to damage the back teeth.
Cough or wheeze - aspiration
Medication review.
What are some of the risks (red flag) associated with GORD?
Coughing up blood might indicate a rupture of an ulcer.
Infection might lead to sepsis.
Reduced swalled could lead to choking, aspiration or malnutrition.
Anaemia could indicate internal bleeding.
What are some of the holistic factors that should be considered with GORD?
Diet and fluid intake - potential triggers
Smoking - irritation/damage of mucosa
Hiatus hernia - increased internal pressure.
History of GORD
Anxiety - commonly associated condition.
Alcohol intake
What education might you give to a patient with GORD?
Avoid known triggers - smoking, coffee, fatty foods.
Lifestyle changes - Lie on left side, smoking cessation, smaller portions, eat 4hrs before sleep, elevate head when sleeping, lose weight, psychological therapies.
Medications that can worsen symptoms - NSAIDs, Betablockers, nutrates, calcium channel blockers, anticholingenics, anti depressants.
What over the counter medication might a patient take for GORD?
Antacids like rennies are made from Aluminium or magnesium compounds and work to reduce acidty of stomach contents.
These can cause delayed absorption of ACE inhibitors and antibacterials.
Alginates like Gaviscon. Made from seaweed and reduce acidity of stomach contents.
Alginates and antacids are often combined.
Weak PPI - Esomeprazole 20mg.
What are some common adverse effects of taking PPI?
Diarrhoea
Interferes with P450 enzyme which can increase or decrease metabolism of other drugs.
Parvati has had a course of PPI from her GP but is still experiencing symptoms of heartburn.
What type of medication might be prescribed as an alternative for long term use?
A Histamine 2 receptor antagonist might be used.
Examples include Cimetidine, famotidine and nezatidine.
Side effects include: GI disturbances, altered liver function.
What role do prostaglandins play in the GI system?
Prostaglandins support vasodilation of gastric mucosa, stimulate mucous production as well as producing bicarbonate (alkaline).