3 years old and upward, full dose. From 1¹⁄₂ years old to 3 years, ¹⁄₂ dose. From 9 to 18 months old, ¹⁄₄ dose. From 4¹⁄₂ to 9 months old, ¹⁄₈ dose. From 1 to 4¹⁄₂ months old, ¹⁄₁₆ dose.