Alginate containing antacids (Gaviscon)

Question 1

What is gaviscon used for?

Answer 1

1) symptom relief of GORD

2) short term relief of dyspepsia (nausea, abdo pain, burping)

Question 2

How does gaviscon work?

Answer 2

• Antacids work by buffering stomach acids.
• Alginates act to increase the viscosity of stomach contents. this reduces reflux.
• A raft forms which separates the gastric contents from the gastro-oesophageal junction.

Question 3

What are the side effects of gaviscon?

Answer 3

• magnesium salts can cause diarrhoea

- aluminium salts can cause constipation

Question 4

What are the contraindications of antacids and alginates?

Answer 4

• sodium and potassium containing preparations should be used in caution in patients with fluid overload, hyperkalaemia (e.g, in renal failure)
• some preparations have sucrose so use in caution with diabetics

Question 5

What are the drug interactions of alginate antacids e.g. gaviscon?

Answer 5

**compounds in alginates can bind to other drugs and reduce their absorption thereby reducing the serum concentration of these drugs - so should be taken at different times.

• ACEi
• Abx e.g. cephalosporins, ciprofloxacin, tetracyclines)
• bisphosphonates,
• digoxin
• levothyroxine
• PPI

Compounds in antacids can increase the alkilinity of urine so increases excretion of :

• aspirin
• lithium

Question 6

What are the red flag symptoms that should be looked out for in GORD?

Answer 6

• bleeding
• vomiting
• dysphagia
• weight loss