Promethazine teoclate and promethazine hydrochloride are phenothiazines. They have marked anti-motion sickness activity, but they also have marked antimuscarinic properties and sedation is common. Both are long-acting.

Promethazine hydrochloride is licensed for use in adults and children from the age of two years. It has the advantage of being available as tablets in two strengths (10mg and 25mg) and as an elixir (5mg per 5ml).

Its sedative effect is sometimes considered to be an advantage in young children on long journeys. Promethazine teoclate is licensed for adults and children from age five years.

For both drugs the initial dose for adults and children over 10 years of age is one 25mg tablet, taken two hours before a short journey or the night before a long journey, with further 25mg doses every 24 hours if required. For teoclate, half the adult dose can be given to children aged 5-10 years.

For hydrochloride, one 10 mg tablet is recommended for children aged 5-10 years, and a 5mg dose of the elixir (5ml) for children aged 2-5 years.