Motion sickness Flashcards
Briefly describe the pathophysiology of motion sickness
- Conflicting motion stimuli fed by vestibular labyrinth, eyes and proprioreceptors to the vestibular nuclei
- Stimuli goes through cerebellum to vomiting centre in medulla oblongata and other areas in CNS
Which age group(s) is/are likely to develop motion sickness?
Children 2-12 yo
Patient factors that may contribute to motion sickness
- Menstruation
- Pregnancy
- History of migraines
- Sleep deprivation
- Tobacco smoking
Early signs of motion sickenss
- Pallor
- Restlessness
- Cold sweat
(late stages: nausea and vomiting)
Key treatment principle of motion sickness
Prevention
Three general non-pharmacological principles to prevent motion sickness
- Reduce vestibular motion: choose locations of vehicle that minimise motions
- Synchronise visual and motion: view outside, choose window seat, or close eyes while holding head still
- Actively synchronize the body with motion: such as actively tilting head
State the mechanism of action of cinnarizine. Describe its dosing regimen for motion sickness
- MoA: Antihistamine-1, with anticholinergic effects
- Dosing: 25 mg at least 30 min before travel, then q4-6h
State the mechanism of action of promethazine. Describe its dosing regimen in motion sickness
- MoA: H1 antihistamine with strong anticholinergic effect
- Dosing: 25 mg 30-60 mins before travel, then q8-12h
State the mechanism of action of scopolamine patch. Describe its dosing regimen in motion sickness
- MoA: Antimuscarinic with anticholinergic properties
- Dose: 1 patch at a hairless area behind the ear 5-6h before travel, then q72h (one patch lasts 72h)
State the mechanism of action of dimenhydrinate. Describe its dosing regimen in motion sickness
- MoA: H1 antihistamine with anticholinergic effect. Metabolised to diphenhydramine
- Dosing: 50-100 mg 30-60 mins before travel, then q6-8h
State the mechanism of action of diPHENhydramine. Describe its dosing regimen in motion sickness
- MoA: H1 antihistamine with anticholinergic properties
- Dose: 25-50 mg at least 30 mins before travel, then q4-6h
Describe the dosing regimen of ginger pills in motion sickness
2-3 tablets at least 30 mins before travel, then 1 tab q2h
What kind of symptoms should you refer a patient to the doctor in nausea and vomiting?
- Severe abdominal pain
- Blood in vomitus
- Head injury, or other neuropathy (e.g. numbness, visual disturbances)
- Signs and symptoms of dehydration
Describe the dose of domperidone for NNV. State the forensic classification and the indication for supplying domperidone if applicable, as well as the maximum supply
- Dose: 10 mg TDS (max 30 mg/day)
- Forensic classification: POM w exemption for 14 days for gastric symptoms (e.g. bloating, belching) or nausea (not vomiting) for patients at least 12yo
- Max supply: 14 days (42 tabs)
Besides ginger, what is/are the complementary treatment(s) that can be used to prevent motion sickness?
Sea band (attached to P6 of meridian system, somewhere around the wrist area)