CAUSES OF TRAVEL SICKNESS:
Travel/Motion sickness is caused by repetitive pronounced movements which affect the vestibular (ie balance) mechanism of the inner ear. In mild cases it may merely induce only slight uneasiness or discomfort and a headache. In more severe cases it can lead to distress, excessive sweating and salivation, pallor, nausea and vomiting.
A straight motorway journey with minimal starting/stopping and turning is less likely to induce travel sickness whilst a journey through winding country lanes can be disastrous for the sufferer. The repetitive pitching, rolling, rotating or up and down motion is the most important factor. Visual stimuli can also play a part which is witnessed by the fact that some people experience a similar form of 'motion sickness' whilst seated watching television or a cinema film with moving pictures involving a lot of motion and camera movement. By far the worst are the large-screen cinemas, such as IMAX, which make many people feel giddy as they feel they are actually being taken on a realistic 'journey' themselves. This illustrates the mismatch of signals reaching the brain - the person feels they are moving although they are actually immobile.
Boats are often the most-avoided form of travel since the pitch and roll of a small boat on waves is inevitable - and there is no easy way to 'escape' - other than by jumping overboard which is neither the safest nor most practical option. Aircraft are relatively stable since many fly high above altitudes at which turbulence most frequently occurs. However, if another traveller should be afflicted by air-sickness then this can trigger sickness in other passengers which has a partly psychological cause - the anticipation or expectation of possible sickness.
Coaches sometimes have a stale smell of diesel fumes and ventilation tends to be minimal - a small air vent above the head with large windows to each side which seem to magnify the rays of the sun and add to the general stuffiness of coaches. and consequent discomfort for passengers. Other causes include anxiety because of previous attacks - ie if you are anticipating travel sickness then you are more likely to actually experience it. Some unfortunate victims become so apprehensive about travel that they feel nauseous on merely stepping aboard a motionless plane or a ship in port. A full stomach, the sight or smell of food and certain fumes such as diesel, petrol or tobacco fumes can make it worse.
Drugs can be used to prevent or minimise the chances of travel sickness but other simple preventative measures might help:
Recline as far as possible
Hold your head firmly against a pillow or head rest
Close your eyes or gaze upon a distant point
Increase ventilation with cool, fresh air
Suck a boiled sweet (mints or barley sugar are recommended)
Recovery from travel sickness can be hastened by fluid replacement at the end of the journey.
Cinnarizine (Stugeron). 30mg 2 hours before travelling then 15mg every 8 hours during the journey if necessary. This drug is the least likely to cause drowsiness. It has a long duration of action at up to 8 hours and takes effect within 30 minutes of ingestion. I tried it for several months for general nausea and giddiness and had no side-effects. It is quite a pleasant pill to take with a slightly sweet taste and almost 'melt-in-the-mouth' texture rather than being bitter or chalky. However, in newer packs the Patient Information Leaflet lists 'stomach upset' amongst the side-effects. Possibly this is referring to a bowel disturbance rather than nausea/vomiting - but it's enough to ring alarm bells. If you are concerned - check with the manufacturer, Janssen, on 01494 567567!
Cyclizine (Valoid). 50mg up to three times per day. In the UK this does not seem to be widely available at Pharmacies.
Dimenhydrinate (Dramamine). 50-100mg 2-3 times per day, taking the first dose 30 minutes before travelling. I have tried this and had no side-effects apart from very mild drowsiness.
Hyoscine hydrobromide (Kwells). Dose 0.3mg. Onset of effect - within one hour. Duration of action - up to 6 hours. Also available, by prescription only, as a skin patch (Scopoderm TTS) to wear behind the ear with a duration of action up to 72 hours. (Hyoscine can also be prescribed at a dose of 80mg per day for IBS.)
Meclozine Hydrochloride (Sea Legs). 12.5mg
Promethazine Hydrochloride take an elixir of 25mg at bedtime on the night before travelling followed by a repeat dose in the morning, if necessary.
Promethazine Theoclate (Avomine, Phenergan). 25mg at bedtime on the night before travelling or 25mg 1-2 hours before travelling. Duration of action - 8-16 hours; onset of effect - within 1 hour. This is also listed in the BNF as being suitable for SEVERE vomiting during pregnancy at a dose of 25mg at bedtime with a maximum daily dose of 100mg per day. However, it is not advisable to take anti-emetic drugs during pregnancy - especially in the first three months. Although there is no evidence of teratogenicity, no drug is safe beyond all doubt and it is recommended that you consult your GP before taking any antihistamine during pregnancy.
Probably the most effective drug for the prevention of travel sickness is Hyoscine - which is also the most sedating. Side-effects of all anti-histamines include: drowsiness, blurred vision, dry mouth, urinary retention. All antihistamines are roughly equal in terms of their effectiveness but some have a longer duration of action than others. Promethazine and dimenhydrinate are more sedating than cyclizine and cinnarzine. Cyclizine does not appear to be stocked in too many pharmacies whereas cinnarizine is widely available. Boots the Chemists (UK) manufacture an own-label product containing hyoscine.
Metoclopramide (Maxolon) and phenothiazines (eg Stemetil) act selectively on the chemo-receptor trigger zone and are ineffective in preventing travel sickness .