Pharmacology Flashcards
(123 cards)
1
Q
What muscles contract to cause vomiting?
A
Abdominal muscles and diaphragm
2
Q
What is retching?
A
Reverse peristalsis
3
Q
What is regurgitation?
A
Effortless movement of swallowed food contents back into the mouth
4
Q
Sickness signals through the vestibular pathway are generally caused by what?
A
Tinnitus or motion sickness
5
Q
Through what nerve do signals from the vestibular pathway travel?
A
Vestibulocochlear nerve
6
Q
Sickness signals through the vagal pathway are generally caused by what?
A
Bacteria/alcohol/smell and vision/pharynx i.e. excess cough
7
Q
What is the central pathway with regards to vomiting?
A
Brainstem emetic control pathway
8
Q
Where will all drugs acting on the chemoreceptor trigger zone act?
A
Outside the blood brain barrier
9
Q
What do enterochromaffin cells in the mucosa do?
A
Release mediators e.g. 5HT
10
Q
What do mediators released by enterochromaffin cells in the mucosa cause?
A
Depolarisation of sensory afferents in the mucosa and AP discharge in vagal afferents to the brainstem
11
Q
What does AP discharge in vagal afferents to the brainstem cause?
A
Coordination of vomiting by the vomiting centre
12
Q
In what state are the stomach, oesophagus and associated sphincters during vomiting?
A
Relaxed
13
Q
Where is the vomiting centre found?
A
Medulla
14
Q
What state is the glottis in during vomiting?
A
Closed to prevent aspiration
15
Q
What usually precedes vomiting?
A
Profuse salivation, increased HR, sweating and nausea
16
Q
Does the motor output of vomiting involve efferents or afferents?
A
Efferents
17
Q
What do vagal efferents cause in vomiting?
A
Shortening of the oesophagus, relaxation of the stomach and contraction of small intestine
18
Q
What do somatic motor neurones cause in vomiting?
A
Contraction of anterior abdominal muscles and diaphragm
19
Q
What do autonomic and somatic efferents cause in vomiting?
A
Increase heart rate and force, increase salivary secretions, pallor and sweaty skin, constriction of bladder and anal sphincters
20
Q
What are some consequences of vomiting?
A
Dehydration, metabolic alkalosis, hypokalaemia, Mallory Weiss tear, aspiration
21
Q
What is a sign of a Mallory Weiss tear?
A
Reddish streaks of fresh blood in vomit
22
Q
What are prochlorperazine and droperidol examples of?
A
Dopamine antagonists
23
Q
What do dopamine antagonists work as at high doses?
A
Anti-psychotics
24
Q
How do dopamine antagonists work?
A
Block chemoreceptor trigger zone
25
What are dopamine antagonists used to treat?
Vomiting associated with neoplastic disease, radiation and drug induced sickness
26
What are side effects of dopamine antagonists?
Sedation and dystonic reactions
27
Where do prokinetic drugs work?
Dopamine pathways
28
What do prokinetic drugs do?
Increase gastric peristalsis and lower oesophageal sphincter tone
29
What is a common anti-emetic in the prokinetic drug class?
Metoclopramide
30
What are granisetron and ondansetron examples of?
5HT3 Receptor antagonists
31
What is a frequent side effect of 5HT3 receptor antagonists?
Headaches, and sometimes GI effects
32
What do 5HT3 antagonists block?
Receptors in the GI tract and CNS
33
What are 5HT3 antagonists used for?
Management of CINV, radiation induced emesis, PONV
34
What are promethazine, cyclizine and cinnarize examples of?
H1 Antihistamines
35
What receptor do H1 antihistamines also often block?
Muscarinic
36
What effect does cinnazine also have?
Antivertigo (tinnitus and Meniere's)
37
What are H1 antagonists most useful for?
Motion sickness, morning sickness, PONV
38
What can H1 antagonists cause and what is the rule associated with this?
CNS depression and sedation- cannot drive
39
What are hyoscine, dicyclomine examples of?
Muscarinic antagonists
40
What are anticholinergics given for?
Motion sickness
41
What can anticholinergics be associated with?
Blurred vision, dry mouth, urinary retention and sedation
42
What classes of drugs can be used as adjuvant anti-emetics?
NK1 receptor antagonists, corticosteroids, benzodiazepines, cannibinoids
43
What drugs are used in anticipatory nausea and vomiting?
Benzodiazepines
44
How long and wide is the large intestine?
1.5m long and 6cm wide
45
What controls opening of the ileocaecal valve?
Gastric distension to cause gastro-ileal reflex
46
What is the ileocaecal valve under control of?
Vagus nerve, sympathetic and enteric nerves
47
What does the ileocaecal valve allow?
Digested contents of small intestine to move into caecum
48
what does the ileocaecal valve prevent?
Colonic bacteria entering the ileum
49
What is absorbed in the large intestine?
H2O, Na+, Cl-, short chain fatty acids
50
what does the large intestine secrete?
K+, HCO3-, mucus
51
What does host bacteria have a role in?
Increasing immunity, promoting motility, synthesising vitamin K2 and free fatty acids, activate some drugs, enterohepatic cyclone
52
What class of drug is useful for long term maintenance of remission of IBD?
Amino salicylates
53
Are aminosalicylates more useful in UC or CD?
UC
54
What do COX and LOX do?
Change lipids into inflammatory components
55
What is the most commonly used aminosalicylate at the moment?
Mesalazine
56
What are some adverse effects of Mesalazine?
Rashes, arthralgias, low folate
57
What should be supplemented during use of aminosalicylates?
Folic acid
58
What is a potent anti inflammatory used in IBD?
Corticosteroids
59
Which IBD are corticosteroids used in?
UC AND CD
60
When are corticosteroids used for IBD?
Reserved for acute flares
61
What does the increase of steroid dependent patients lead to the use of?
Immunosuppressants
62
What do immunosuppressants do?
Inhibit T lymphocyte function
63
What is the rate of onset of immunosuppressants?
Slow
64
What is the immunosuppressant used in IBD?
Azathioprine
65
What are adverse effects of immunosuppressants?
Bowel movement suppression and hepatotoxicity
66
What are some other immunosuppressant drugs?
6-mercaptopurine and methotrexate
67
What are biological agents?
Monoclonal antibodies
68
When are biological agents only really used?
Patients unfit for surgery
69
What do biological agents block the action of?
TNF alpha
70
What is a common side effect of biological agents and so what should be given in advance?
Hypersensitivity reactions- give antihistamines
71
What is the common name ending for all biological agents?
.....mab
72
What is drug treatment secondary to in IBS?
Diet and lifestyle changes
73
What drugs can be given in IBS?
Antispasmodics, laxatives or anti motility agents
74
What do anti-spasmodic drugs reduce in IBS?
Cramps
75
What are the two types of anti-spasmodic drugs?
Anti muscarinic agents and direct smooth muscle relaxants
76
Which anti-spasmodic drug is better tolerated?
Direct smooth muscle relaxants
77
How do anti muscarinic anti-spasmodic drugs work?
Inhibit parasympathetic activity in the GI tract
78
What are dicycloverine hydrochloride, propantheline bromide examples of?
Anti muscarinic anti spasmodics
79
What are Alverine, mebeverine and peppermint oil examples of?
Direct smooth muscle relaxants
80
When anti-spasmodic drugs fail, what can be used to relieve pain in IBS?
Tricyclic antidepressants at low doses
81
Where does the majority of reabsorption occur?
Small intestine
82
Which co-transporters are the major mechanisms of post-prandial Na+ reabsorption? What is especially useful about these transporters?
Na+/glucose and Na+/amino acids- remain in tact even in severe diarrhoea
83
What type of transport occurs through Na+ co-transporters?
Secondary active transport
84
What are neither the Na+/glucose or Na+/amino acid transporters regulated by?
cAMP or Ca++
85
What is diarrhoea defined as?
Loos of fluids and solutes from the GI tract in excess of 500mls per day
86
What is secretory diarrhoea?
Increase in adenyl cyclase
87
What are the 3 key treatments involved in severe acute diarrhoea?
Maintenance of fluid and electrolyte balance
Use of antimicrobial agents when needed
Use of anti-motility and anti-spasmodic agents
88
What is the most important treatment for diarrhoea?
Hydration
89
When is fluid loss classed as severe?
Lost more than 10% of body weight
90
How many Na+ bind to the SGLT1 transporter and what does this cause?
2 Na+, increases affinity for glucose
91
What do oral rehydration salts contain?
Glucose, NaCl, sodium bicarbonate, potassium chloride
92
What do oral rehydration salts cause?
Absorption of Na+ and glucose by SGLT1 which causes absorption of water
93
What antibiotics are used in C. diff colitis?
Less severe- oral metronidazole
| More severe- oral vancomycin
94
What antibiotic is used in protozoan infection?
Metronidazole
95
Who should not receive anti-motility agents?
Under 12, acute infective diarrhoea, IBD, IBS and diverticulosis
96
When cam anti-motility agents be used?
Short term measure in exhausting or idiopathic diarrhoea or mild traveller's diarrhoea
97
Opioid drugs have what kind of effect?
Constipating
98
What are the main opioids used in diarrhoea?
Loperamide, diphenoxylate and codeine (rare)
99
What makes loperamide the opioid of choice for diarrhoea?
Pretty selective for GI tract
100
What are the side effects of diphenoxylate?
Nausea, headache, weakness, blurred vision
101
What can cause constipation?
suppressing urge to defecate, decreased colonic activity, lack of exercise
102
What do laxatives provide?
Mild action resulting in the passage of soft but formed stools
103
What do purgatives produce?
Stronger action leading to more fluid evacuation
104
When should neither laxatives or purgatives be used?
When there is physical obstruction to the bowel
105
What can laxative abuse lead to?
Hypokalaemia
106
What is a common side effect of stimulant purgatives?
Abdominal cramps
107
What are the metabolic functions of the liver?
Protein, fat and carbohydrate metabolism
108
The liver is the major site of degradation for which hormones?
Insulin, steroid hormones, glucagon and ADH
109
Normal thyroid function is dependent n the hepatic formation of what?
T4-T3 thyroid hormones
110
Liver is involved in the activation of which vitamin?
B3
111
The liver is involved in the storage of which vitamins?
A, D, E, K, B12
112
What are Kupffer cells and what do they do?
Liver phagocytes which destroy cellular debris and invading bacteria
113
What stimulates the gallbladder to contract and cause the Sphincter of Oddi to open?
Chime in the duodenum
114
What allows the smooth muscle of the gallbladder to contract?
CCK and vagal impulses
115
Ursodeoxycholic acid is only of use in which type of gallstones?
Cholesterol
116
Why should you not use morphine in biliary colic?
Constricts sphincter of Oddi and increases heoatic pressure
117
What analgesics should be used in biliary colic instead of morphine?
Buprenorphine or pethedine
118
What drugs are used for relief of biliary spasm?
GTN or atropine
119
Bile acid binding resins are a drug used for hypercholesterolaemia. What can they be used for in terms of GI and how?
Cholestatic jaundice by increasing the bile salts in the blood
120
Why are bile acid binding resins not ideal drugs?
Large doses are required, have GI effects, and give a deficiency of fat soluble vitamins
121
What drugs can be given for hepatic encephalopathy?
Lactulose and antibiotics
122
What is the function of lactulose in hepatic encephalopathy?
It is not digested or absorbed in the ileum. Breakdown products in the colon are acidic which decreases pH
123
Why are antibiotics used in hepatic encephalopathy?
Suppress colonic flora to inhibit ammonia generation
