Therapeutic options and referral

Question 1

What are antacids made of and what are some of the brand names?

Answer 1

Antacids consists of magnesium, aluminium, sodium and calcium salts

Brand names include:
Rennies, Tums and Settlers

Question 2

How do antacids work?

Answer 2

Antacid salts bind to acid within the stomach causing a neutralisation reactions causing release of CO2 (burp).
Alkalinisation can increase the LOS sphincter pressure (reducing GORD) and induce mucosal protection by stimulation of prostaglandin synthesis (allowing ulcer healing).

Question 3

What are some of the key counselling points for antacids use?

Answer 3

Liquids work more effectively, increased surface area
Tablets should be chewed
Take one after a meal due to reduced gastric emptying (3 hours effect compared to 1hour if not taken after a meal)
Short term use
Not be used as a preventative

Question 4

Why are antacids limited to short term use?

Answer 4

Presence of antacids causes an increase in pH within the stomach. Acid production increases with pH and therefore can cause acid rebound.

Question 5

What are some of the indications of antacids?

Answer 5

Functional dyspepsia
Gastric and duodenal ulcers
Oesophagitis
GORD

Question 6

What are some of the main side effects of antacids?

Answer 6

Aluminium:
Constipation
Osteoporosis (binding to phosphate in the gut)
Neurotoxicity (absorbed)

Magnesium:
Diarrhoea

All can cause acid rebound, therefore only short-term use

Question 7

When should excessive sodium based antacids be avoided?

Answer 7

In hypertensive / cardiac patients

Question 8

Are antacids safe for use in pregnancy?

Answer 8

Yes but mindful of sodium content

Question 9

What drug interactions should you be mindful of with antacid use?

Answer 9

Antacids will damage the enteric coating of some drugs
Binding with tetracyclines and iron based drugs

Question 10

How do alginates work?

Answer 10

Alginates are formulated with an antacid and once they reach the acidic pH within the stomach they form a high pH viscous mass, essentially a ‘raft’ which traps air and bubbles (due to the antacid reaction causing the release of carbon dioxide which is trapped within the raft).
This rafts sits on top of the stomach and protects the oesophageal mucosa from reflux.

Question 11

What is the purpose of Simethicone (Dimeticone)?

Answer 11

It is an anti-foaming agent which reduces the surface tension of intra-gastric air bubbles, breaks down the bubble and lets smaller bubbles escape (reducing the feeling of bloatedness).

Question 12

What are some examples of H2 antagonists?

Answer 12

Cimetidine, Ranotidine, Famotidine, Nizatidine

Question 13

How do H2 antagonists work?

Answer 13

Compete for H2 receptor binding on parietal cells, preventing activation by histamine and hence acid secretion.
Large stimulus such as a large meal will override these effects.

Question 14

How does the DOA/onset time compare to that of antacids?

Answer 14

Longer duration of action and time of onset

Question 15

What are the beneficial outcomes of H2 antagonists on peptic ulcer disease?

Answer 15

High healing rates
However does not affect relapse (has H pylori been eradicated)

Question 16

What are the beneficial outcomes of H2 antagonists on GORD?

Answer 16

80-90% mild oesophagitis improvement after 12 weeks
Not used for moderate to severe disease
PPI is first line so would only expect use is PPI was not effective

Question 17

What is the side effect profile like for H2 antagonists?

Answer 17

Only 1-7% experience side effects

Question 18

What are the associated side effects for some of the H2 antagonists?

Answer 18

Increased prevalence of headache and dizziness in comparison to placebo
Cimetidine - gynaecomastia (swelling of male breast tissue), impaired libido
Nizatidine - abnormal dreams, sweating

Confusion in the elderly

Question 19

What are the main drug interactions associated with Cimetidine?

Answer 19

Cimetidine is a CYP 450 inhibitor, and therefore drugs that rely on this enzyme for metabolism have increased concentrations in vivo.
Including theophylline, warfarin, phenytoin

Question 20

Which H2 antagonist can be bought OTC?

Answer 20

Ranitidine (Zantac 75)

Question 21

What is Ranitidine indicated for?

Answer 21

Symptomatic relief of heartburn, dyspepsia and hyperacidity

Question 22

What are some counselling points for use of Ranitidine?

Answer 22

Maximum 6 day continuous use before seeking advice from the GP/Pharmacist
OTC- maximum 2 tablets in 24 hours whereas
POM - 150mg twice daily or 300mg at night

Question 23

How is Ranitidine often used?

Answer 23

Prophylactically before a meal known to induce dyspeptic like symptoms

Question 24

What are some examples of proton pump inhibitors?

Answer 24

Lansoprazole, Esomeprazole, Pantoprazole, Omeprazole

Question 25

Why are PPIs enteric coated?

Answer 25

They are acid labile and hence destroyed by contents within the stomach, so are enteric coated to ensure absorption into the small intestine

Question 26

Why would you co-prescribe an antacid for the first couple of days whilst also taking a PPI?

Answer 26

PPIs take a couple of days to reach full effect and therefore an antacid can provide symptomatic relief almost instantly

Question 27

How do PPIs work?

Answer 27

Proton pump inhibitors (PPIs) block the gastric H+/K+ -ATPase, inhibiting gastric acid secretion regardless of whether the parietal cell is stimulated

Question 28

What is the effect of PPIs on gastric acid secretion?

Answer 28

20mg Omeprazole blocks 80% of gastric acid secretion 40mg Omeprazole blocks 100% of gastric acid secretion

Question 29

Why are PPIs used in preference for the treatment of ulcers?

Answer 29

They heal ulcers more quickly than H2 antagonists, the healing rate is the same after 8 weeks however. Also superior in the treatment of reflux and GORD.

Question 30

What are some of the side effects associated with PPIs?

Answer 30

Nausea Vomiting Flatulence Diarrhoea Epigastric pain Dry mouth Headache Arthralgia Myalgia Risk of bacterial overgrowth (due to absence of acid) - increased risk of Helicobacter or Salmonella infection Rebound acid after prolonged treatment (use lowest dose, as needed)

Question 31

Should PPIs be taken with food?

Answer 31

No, taking Lansoprazole with food reduces the bioavailability

Question 32

Which PPI is licensed over the counter?

Answer 32

Esomeprazole

Question 33

What are some of the counselling points for PPI sale OTC?

Answer 33

Indicated for reflux in over 18s Should be swallowed whole with plenty of liquid 20mg until symptoms improve then 10mg

Question 34

When should the OTC sale of a PPI be referred to the GP?

Answer 34

No improvement after 2 weeks If treatment is required continuously for more than 4 weeks Patient is over 45 and presents with new or changed symptoms

Question 35

List other drugs that can be used in the treatment of upper GI conditions.

Answer 35

Metoclopramide and Domperidone Sucralfate Bismuth Misoprostol

Question 36

How does Metoclopramide and Domperidone work?

Answer 36

Increases gastric emptying and LOS tone

Question 37

Why is domperidone not used OTC anymore?

Answer 37

Due to CVD risk

Question 38

How does Sucralfate work?

Answer 38

Polymerizes below pH4 to form a sticky gel Protective barrier over ulcer (adheres strongly to ulcer) Physical protection and allows bicarbonate to re-establish pH gradient

Question 39

How does Bismuth work?

Answer 39

May act similarly to sucralfate Strong affinity for mucosa, especially in ulcer craters May blacken teeth and stools

Question 40

How does Misoprostol work?

Answer 40

Promotes ulcer healing by stimulating protective mechanisms – sometimes used with NSAIDs

Question 41

What is the main treatment for gastritis, PUD or functional dyspepsia?

Answer 41

* Removal of causative agents * Dietary changes * Symptomatic management * H2 antagonists or Proton pump inhibitors Undiagnosed upper GI conditions can be treated OTC with care not to mask symptoms of gastric cancer

Question 42

What is the main treatment for GORD?

Answer 42

Lifestyle and dietary changes Alginate products or PPIs DON'T use H2 antagonists first line (only in inadequate response) Undiagnosed upper GI conditions can be treated OTC with care not to mask symptoms of gastric cancer

Question 43

When should referrals be made for dyspeptic symptoms?

Answer 43

*Patient over 45 with a new/changed symptoms of heartburn or dyspepsia *Child presentations *Continued nausea and vomiting * Continuous dyspepsia * Increasing severity * Weight loss, loss of appetite, sign of anaemia * Pain on exercise - cardiac origin? * Dysphagia * Unexplainable pain on swallowing * Blood in vomit or stools