Alimentary Pharmacology Flashcards Preview

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Flashcards in Alimentary Pharmacology Deck (34):
1

What drugs are used for acid suppression?

Antacids
Alginates
H2 receptor antagonists
Proton pump inhibitor

2

What drugs affect GI motility?

Anti-emetics
Anti-muscarinics (anti-spasmodics)
Anti-motility

3

What drugs are used in IBD?

Aminosalicylates
Corticosteroids
Immunosuppressants
Biologics

4

How do antacids work?

Neutralise gastric acid, contain Mg or Al (Maalox)

5

How do alginates work?

Form a viscous gel that frats on stomach contents, reduces reflux (Gaviscon)

6

How do H2 receptor antagonists work?

Block histamine receptor, reduces acid secretion

7

How are H2 receptor antagonists administered?

Oral or IV

8

How do proton pump inhibitors work?

Block proton pump (K+/H+ pump), reduces acid secretion

9

How are proton pump inhibitors given?

Oral or IV (Omeprazole)

10

What are the complications of proton pump inhibitors?

GI upset
Predisposition to c diff infection
Hypomagnesaemia
B12 deficiency

11

Name drugs which increase GI motility

Metoclopramide
Domperidone

12

How does domperidone affect GI motility?

Blocks dopamine receptors which inhibit post synaptic cholinergic neurones

13

Name drugs which decrease GI motility?

Loperamide
Opioids

14

How do loperamide and opioids work to decrease GI motility?

Action is via opiate receptors in GI tract to decrease ACh release, thereby muscle contraction

15

How do anti-spasmodics work to affect GI motility?

Anti cholinergic muscarinic antagonists inhibit smooth muscle constriction, producing muscle relaxation and reduction spasm
Smooth muscle relaxants
Calcium channel blockers reduce calcium required for muscle contraction

16

What are the 4 types of laxatives?

Bulk (Isphagula)
Osmotic (Lactulose)
Stimulant (Senna)
Softeners (Arachis oil)

17

How do laxatives work?

Increasing bulk, drawing fluid into gut and softening stool

18

What are the issues with laxatives?

Obstruction (can rupture colon)
Misue

19

What are the main aminosalicylates?

Mesalazine
Olsalazine

20

How are aminosalicylates administered?

Oral
Rectal

21

What are the adverse affects of aminosalicylates?

GI upset
Blood dyscrasia
Renal impairment

22

How are corticosteroids administered?

Oral
IV
Rectal

23

What are the contraindications of corticosteroids?

Osteoperosis
Cushingoid features (weight gain)
Increased susceptibility to infection
Addisonian crisis in abrupt withdrawal

24

How do immunosuppressants work in IBD?
(Azathioprine)

Prevent the formation of purines required for DNA synthesis, reduces immune cell proliferation

25

What are the adverse affects of immunosuppressants?

Bone marrow suppression
Azathioprine hypersensitivity
Organ damage (lung, liver, pancreas)
Numerous drug interactions

26

How do biologics work in IBD? (Inflixamab)

Prevents action of TNFalpha

27

What are the contraindications of Inflixamab?

Cannot be used when pregnant, breast feeding, have a serious infection, TB or multiple sclerosis

28

What are the adverse affects of Inflixamab?

Risk if infection
Infusion reaction
Anaemia
Thrombocytopenia
Neutropenia

29

What drugs are used to control biliary secretions?

Cholestyramine
Ursodeoxycholic acid

30

How does cholestyramine work to control biliary secretions?

Reduces bile salts by binding with them in the gut then excreting as an insoluble complex

31

What are the adverse affects of cholestyramine?

May affect absorption of other drugs
May affect fat soluble vitamin absorption, decrease levels of vitamin K her fore affecting clotting and warfarin

32

How does ursodeoxycholic acid work to control biliary secretions?

Inhibits enzyme involved in formation of cholesterol, altering amount in bile and slowly dissolving non calcified stones

33

What are the main gastrointestinal adverse affects due to drugs?

Diarrhoea
Constipation
Bleeding
Ulceration
Changes to gut bacteria
Drug induced liver injury

34

What are the risk factors for drug administration?

Age (elderly)
Sex (female)
Alcohol consumption
Genetic factors
Malnourishment