CNS - NAUSEA

Question 1

When should antiemetics be given?

Answer 1

• When the cause is known

- need to identify the cause first e.g. DKA, digoxin, epileptic overdose

Question 2

What is effective in nausea and vomiting that result from underlying conditions?

Answer 2

antihistamines

Question 3

What are some examples of phenothiazines?

Answer 3

• prochlorphenazine, perphenazine, trifluoperazine = less sedating
• chlorphenazine = sedating

Question 4

What are phenothiazines effective against?

Answer 4

• prophylaxis and treatment of n&v caused by - neoplastic disease, radiation sickness, emesis caused by other drugs e.g. opioids

Question 5

Metoclopramide:

Answer 5

• acts directly on GI tract
• Can only be prescribed for up to 5 days due to risk of neurological side effects
• usual dose = 10mg TDS
• IV dose - administered slowly over 3 minutes

Question 6

Domperidone:

Answer 6

• does not cross bbb = less central effects such as sedation
• good to use in parkinsons for nausea caused by drugs
• use at the lowest effective dose for the shortest period of time - max 7 days
• CI in cardiac disease or drugs that prolong QT
• Recommended dose in adults over 12 and over 35kg = 10mg up to TDS

Question 7

Ondansetron and Granisetron:

Answer 7

• management of n&v in pts receiving cytotoxics and in postperative n&v
• palonosetron = for high cytotoxic chemo - can also be used in combo w netupitant

Question 8

Dexamethasone:

Answer 8

• can be used in vomiting associated with cancer chemo

- can be used with metoclopramide, prochlorperazone, lorazepam

Question 9

What is appropriate to give if n&v is really bad in pregnancy?

Answer 9

antihistamine e.g. promethazine

Question 10

What are risk factors for post operative surgery?

Answer 10

• type of anaesthetic used
• duration of surgery
• females
• non smokers

Question 11

What is usually given to prevent motion sickness?

Answer 11

hyoscine