How does it work? Avomine tablets contain the active ingredient promethazine teoclate, which is a type of medicine known as an antihistamine. It is used to prevent travel sickness & nausea. Promethazine works by preventing the action of histamine. Promethazine blocks histamine from binding to its receptors in various parts of the body, including an area in the brain known as the vomiting centre. The vomiting centre is responsible for causing feelings of sickness & for the vomiting reflex. It is activated when it receives nerve messages from the vestibular apparatus in the middle ear. The vestibular apparatus provides constant feedback to the brain about the position of our body. When something disturbs the vestibular apparatus, such as movements of the head when travelling by boat or car, nerve signals are sent from the vestibular apparatus to the vomiting centre. This can cause the symptoms of motion sickness, such as nausea, dizziness or spinning sensations (vertigo) & vomiting. Promethazine can be used to prevent motion sickness, because by blocking the histamine receptors in the vomiting centre, it prevents disturbances in the middle ear from activating the vomiting centre. To prevent travel sickness on short journeys Avomine tablets need to be taken at least one or two hours before travelling. For long journeys Avomine tablets need to be taken at bedtime, starting the day before setting out. What is it used for? Preventing & relieving travel sickness. Nausea & vomiting. Vertigo.