I just bought some Gravol for my kids. It's even called "Gravol for Children". It has dosage information for children 2 to under 6 years, and for children 6 to under 12 years. There is no dosage information for anybody older than 12 years old. But there is the following:
Caution: Do not exceed the recommended dosage. May cause drowsiness. Avoid driving a motor vehicle or performing tasks requiring mental alertness. Avoid alcoholic beverages. Do not take if you have: glaucoma, chronic lung disease, difficulty in urination due to an enlargement of the prostate gland, or if you are pregnant or breast-feeding unless directed by a physician. [and some other cautions not quite so inappropriate]
I had to take it back - my chain smoking, alcoholic, pregnant, car driving 6-year-old daughter couldn't take them!