Nausea and Vommiting

Question 1

Vomiting is coordinated by?

Answer 1

the vomiting centre + chemoreceptor trigger zone in the brain stem

Question 2

The vomiting center contains?

Answer 2

1. muscarinic M1 receptors 2. histamine H1 receptors 3. neurokinin 1 NK1 receptors 4. serotonin 5-HT3 receptors

Question 3

Which part of the brain triggers vomiting after seeing something repulsive?

Answer 3

cortex

Question 4

Which part of the brain triggers vomiting during motion sickness?

Answer 4

vestibular apparatus

Question 5

Which part of the brain triggers vomiting after ingesting a toxin ?

Answer 5

stomach

Question 6

The drugs which are recommeded for the induction of vomiting in cases of poisoning are?

Answer 6

1. apomorphine 2. ipecacuanha syrup

Question 7

Describe the syrup of ipecac emetic?

Answer 7

Prepared from the root of the ipecacuanha plant

Question 8

What is its function?

Answer 8

induces emesis

Question 9

What are the side effects?

Answer 9

1. drowsiness, diarrhea and stomahc ache 2. myocardial conduction disturbances

Question 10

Describe the action?

Answer 10

induces vomiting within 20-30 minutes - The emetic action is increased if 200-300ml water is taken immediately after ingesting the syrup

Question 11

What is the recommeded dosage?

Answer 11

1. adults - 20ml orally followed by 200-300ml water 2. children - 10ml orally followed by 100-150ml water

Question 12

Describe the action of apomorphine hydrochloride?

Answer 12

1. acts directly on the CTZ and induces vomiting within 10 minutes after IM or SC injection 2. More effective if 200 to 300ml water is given by mouth before injection

Question 13

Emetics are contraindicated in?

Answer 13

unconscious patients

Question 14

An overdose can cause?

Answer 14

euphoria, excitement, convulsion, violent vomiting, acute circulatory failure and respiratory depression

Question 15

How can the depressant action be reversed?

Answer 15

administration of a narcotic antagonist like naloxone

Question 16

Describe the dosage of apomorphine hydrochloride tablests?

Answer 16

1. adults - 6mg 2. children - 0.06mg/kg

Question 17

What are antiemetics?

Answer 17

serotonin 5-HT3 antagonists

Question 18

Give examples?

Answer 18

1. ondansetron 2. granietron 3. dolasetron 4. palonosetron

Question 19

Describe the action?

Answer 19

Block central 5-HT3 and peripheral (main effect) 5-HT3 receptors on intestinal vagal and spinal afferent nerves - prevent emesis due to vagal stimulation and chemotherapy

Question 20

What are the uses of antiemetics?

Answer 20

1. Prevention of acute chemotherapy-induced nausea and emesis and postoperative nausea and vomiting 2. Prevention and treatment of nausea and vomiting in patients undergoing radiation therapy

Question 21

How is the efficacy enhanced?

Answer 21

combination therapy with dexamethasone and NK1-receptor antagonist

Question 22

Describe the adverse effects?

Answer 22

Headache, dizziness, and constipation