Antihistamines are less effective at treating motion sickness than hyoscine.
They are usually taken 1 to 2 hours before your journey but tend to cause drowsiness or sleepiness and is not recommended if you need to stay alert such as if you are driving.
The cause of motion sickness is complex and not fully understood, but most experts believe that it arises due to conflicts in sensory input to the brain.
The brain senses motion through different signaling pathways from the inner ear (sensing motion, acceleration, and gravity), the eyes (vision), and the deeper tissues of the body (proprioceptors).
This is based upon the principle that habituation to certain movements and motions (getting accustomed to the type of motion) can occur, leading to a decrease in motion sickness over time when repeatedly exposed to the same movements.
In most cases, motion sickness can be treated without a visit to the doctor.
Car sickness, seasickness, and air sickness are examples of motion sickness. Other common signs are sweating, increased salivation, and a general feeling of discomfort and not feeling well (malaise).
Complex types of movement, especially slow movement or movement in two different directions (such as up and down plus back and forth) at the same time (commonly the movements of a boat in rough water) are most likely to cause motion sickness. The severity of motion sickness can vary widely, even in the same individual on different days.
Common side effects of hyoscine include drowsiness, blurred vision and dizziness.
As hyoscine can cause drowsiness, avoid taking it if you're planning to drive.