Urinary excretion increases with acidification and decreases with alkalization of the urine. There are few published reports of toxicity due to pseudoephedrine and no case of fatal overdosage has been reported. Since the action of sustained release products may continue for as long as 12 hours, treatment of overdosage should be directed toward reducing further absorption and supporting the patient for at least that length of time. Either isotonic or half-isotonic saline may be used for lavage. Saline cathartics, such as Milk of Magnesia, are useful for hastening the evacuation of unreleased medication.
Adrenergic receptor blocking agents are antidotes to pseudoephedrine.
In practice, the most useful is the beta-blocker propranolol which is indicated where there are signs of cardiac toxicity. Theoretically, pseudoephedrine is dialyzable but procedures have not been clinically established.