The maximum daily dosage for pseudoephedrine is 240 milligrams (mg.). Your actual dosage may vary based on the brand you use and the severity of your symptoms. For example, immediate-release tablets contain 30 to 60 mg. of pseudoephedrine, and should be taken every four to six hours as needed. An extended-release tablet contains 120 mg. of pseudoephedrine. You should not take more than one of these tablets in a 12-hour period or two in 24 hours. The maximum daily dose for a child six to 12 years of age is 120 mg. The maximum daily dose for a child four to five years of age is 60 mg. Talk to your doctor if you have questions about what is a safe and effective dosage for you.