Motion sickness

Motion sickness is an autonomic syndrome similar to that which accompanies vertigo, the difference being that motion is the trigger. The vestibular system has many cholinergic and histaminergic receptors, so anticholinergic and antihistamine drugs are first choice for prophylaxis of motion sickness. These drugs are effective in most patients, but can be sedating and impair performance. Hyoscine is less sedating than an antihistamine but is more likely to have anticholinergic adverse effects. Motion sickness is more common in patients with vestibular migraine, and migraine prophylaxis is often effective in these patients.

It is best to take an anticholinergic or antihistamine drug before travel, as these drugs are more effective at preventing motion sickness than treating it.

For an adult, use:

1 cyclizine 50 mg orally, 1 to 2 hours before travel. Repeat 6- to 8-hourly if needed, up to 150 mg in 24 hours motion sickness    

OR

1 dimenhydrinate+hyoscine hydrobromide+caffeine tablets 50+0.2+20 mg, 1 to 2 tablets orally, 30 minutes before travel. Repeat 4- to 6-hourly if needed, up to 4 tablets in 24 hours motion sickness dimenhydrinate+hyoscine+caffeine dimenhydrinate+hyoscine+caffeine

OR

1 hyoscine hydrobromide 300 to 600 micrograms orally, 30 minutes before travel. Repeat 4- to 6-hourly if needed, up to 1200 micrograms in 24 hours motion sickness    

OR

1 promethazine 25 mg orally, 1 to 2 hours before travel. Repeat 6- to 8-hourly if needed, up to 100 mg in 24 hours. motion sickness promethazine    

For a child, use:

1 dimenhydrinate+hyoscine hydrobromide+caffeine tablets 50+0.2+20 mg (child 4 to 7 years: quarter to half tablet; 8 to 13 years: half to 1 tablet) orally, 30 minutes before travel. Repeat 6- to 8-hourly if needed, up to 3 doses in 24 hours. Do not use in children younger than 4 years dimenhydrinate+hyoscine+caffeine dimenhydrinate+hyoscine+caffeine

OR

1 hyoscine hydrobromide (child 2 to 7 years: 75 micrograms; 8 to 12 years: 150 to 300 micrograms) orally, 30 minutes before travel. Repeat 6-hourly if needed (child 2 to 7 years: up to 300 micrograms in 24 hours; 8 to 12 years: up to 600 micrograms in 24 hours). Do not use in children younger than 2 years    

OR

1 promethazine (6 to 12 years: 10 mg) orally, 1 to 2 hours before travel. Repeat 6- to 8-hourly if needed, up to 3 doses in 24 hours. Do not use in children younger than 6 years. promethazine