Recommended dosage
Start
Adults and Children 12 Years and Older
For hay fever, the usual dosage is 60 milligrams twice a day or 180 milligrams once a day. For hives, it’s 60 milligrams twice a day. If you have kidney problems, your doctor may have you take only one 60-milligram dose daily.
Children 6 through 11 years old
For hay fever or hives, the usual dosage is 30 milligrams twice a day. Children with kidney problems may be prescribed only one 30-milligram dose each day.