GI and Liver Flashcards
(31 cards)
Alginates/Antacids
2 examples
- Gaviscon
2. Peptac
Alginates
Mechanism of action
- Alginates increase the viscosity of the stomach contents, which reduces reflux - form a ‘floating raft’
Antacids
Mechanism of action
- Antacids buffer stomach acid
e. g. sodium bicarbonate, magnesium, aluminium salts
Alginates/Antacids
Uses
- GORD
- Dyspepsia
Alginates/Antacids
Side effects
- Compound alginates cause few side effects
- Mg salts - diarrhoea
- Al salts - constipation
Alginates/Antacids
Contraindications
- Well tolerated and safe in pregnancy
- Careful if they contain sodium or potassium
Alginates/Antacids
Interactions
- Increase alkalinity of urine so increase excretion of aspirin and lithium
- Reduce serum concentrations of ACE-I’s, antibiotics, digoxin, levothyroxine, PPI’s
Aminosalicylates
2 examples
- Mesalazine = 1st line for UC
2. Sulfasalazine = alternative
Aminosalicylates
Mechanism of action
- Release 5-aminosalicyclic acid (5-ASA)
- Anti-inflammatory and immunosuppressive effects
Aminosalicylates
Uses
- UC
- Rheumatoid arthritis (Sulfasalazine = DMARD)
Aminosalicylates
Side effects
- GI upset
- Diarrhoea
- Headache
- Sulfasalazine -> oligospermia (reduction in sperm)
Aminosalicylates
Contraindications
Aspirin hypersensitivity
Both are Salicytates
Aminosalicylates
Interactions
Have a pH sensitive coating, so broken down differently with drugs that alter gastric pH, e.g. PPI’s, lactulose
Iron
2 examples
- Ferrous fumarate
2. Ferrous Sulphate
Iron
Mechanism of action
- Replenishes iron stores - for Haem synthesis in Hb
- Bets absorbed in ferrous state in jejunum and duodenum
- Transported as transferrin and stored as ferritin in liver, BM, spleen, muscle
Iron
Uses
- Iron deficiency anaemia
- Prophylaxis of IDA - in patients with RF - mennorhagia, malabsorption, gastrectomy
Iron
Side effects
- GI upset
- Black stool
- If IV - injection site irritation
Iron
Contraindications
May exacerbate bowel syndromes in patients with IBD/strictures
Iron
Interactions
Affects absorption of Levothyroxine and bisphosphonates - take these 2 hours before
Anti-motility drugs
2 examples
- Loperamide
2. Codeine phosphate
Anti-motility drugs
MofA
- Agonist of opioid receptors in GI tract, increasing non-propulsive contractions of the gut SM but reducing peristalsis
- Slows down bowel contents (allowing more time for water re absorption –> hardening stools) and increases anal sphincter tone
- Loperamide = opioid, but does not penetrate CNS so no analgesic effect
Anti-motility drugs
Uses
- Diarrhoea (usually IBS or gastroenteritis)
Anti-motility drugs
Side effects
- Abdo pain
- Flatulence
- Constipation
- Opioid toxicity/dependence if CP
Anti-motility drugs
Contraindications
Avoid in UC and C.diff colitis
