Ondansetron Flashcards
1
Q
Presentation
A
4 mg ODT
8 mg in 4 ml glass ampoule
2
Q
Pharmacology
A
Anti-emetic
Actions
- 5HT3 antagonist which blocks receptors both centrally and peripherally
3
Q
Metabolism
A
By the liver
4
Q
Indications
A
- undifferentiated nausea and vomiting
- prophylaxis for spinally immobilised or eye injured pt’s
- vestibular nausea in pt’s < 21 yrs
5
Q
Contras
A
- known hypersensitivity
- concurrent apomorphine use (anti-depressant)
- known long Q-T syndrome
- hypokalaemia or hypomagnesaemia
6
Q
Precautions
A
- Pt’s with liver disease should not receive more than 8 mg per day
- Pt’s on diuretics may have an underlying electrolyte imbalance
- Contains aspartame and should not be given to pt’s with phenylketonuria
- concurrent use of tramadol
- pregnancy
7
Q
Route of administration
A
- Oral - ODT
- IV
- IM
8
Q
Side effects
A
Rare (< 0.1%)
- Hypersensitivity reactions incl anaphylaxis
- Q-T prolongation
- widened QRS complex
- tachyarrythmias incl AF and SVT
- seizures
- extrapyramidal reaction
- visual disturbances incl transient loss of vision
Common (> 1%)
- constipation
- headache
- fever
- dizziness
- rise in liver enzymes
9
Q
Special notes
A
IV doses should be delivered as a slow push (minimum 30 secs)
10
Q
Oral effects
A
Onset: 2 mins
Peak: 20 mins
Duration: 120 mins
11
Q
IV effects
A
Onset: 5 mins
Peak: 10 mins
Duration: 2.5 - 6.1 hrs
12
Q
Nausea and Vomiting
A
Undifferentiated N&V
- 4 mg ODT, repeat 4mg ODT @ 5-10 mins
- if unable to tolerate ODT or IV in situ, 8 mg IV
Max 8mg ODT/IV or in combination
13
Q
Vestibular nausea
A
Pt < 21 yrs
- 4 mg ODT, repeat 4mg ODT @ 5-10 mins
- if unable to tolerate ODT or IV in situ, 8 mg IV
Max 8mg ODT/IV or in combination
14
Q
Prophylaxis
A
- Awake pt with potential for spinal injuries and immobilised
- Eye trauma eg: penetrating eye injury or hyphema
- 4 mg ODT, repeat 4mg ODT @ 5-10 mins
- if unable to tolerate ODT or IV in situ, 8 mg IV
Max 8mg ODT/IV or in combination
