Canada
Health Canada has investigated the risks and benefits of pseudoephedrine and ephedrine/Ephedra. Near the end of the study, Health Canada issued a warning on their website stating that those who are under the age of 12, or who have heart disease and may have strokes, should avoid taking pseudoephedrine and ephedrine. Also, they warned that everyone should avoid taking ephedrine or pseudoephrine with other stimulants like caffeine. They also banned all products that contain both ephedrine (or pseudoephedrine) and caffeine.Products whose only medicinal ingredient is pseudoephedrine must be kept behind the pharmacy counter. Products containing pseudoephedrine along with other medicinal ingredients may be displayed on store shelves but may be sold only in a pharmacy when a pharmacist is present. Colombia
The Colombian government prohibited the trade of pseudoephedrine in 2010. Japan
Medications that contain more than 10% pseudoephedrine are prohibited under the Stimulants Control Law in Japan. Mexico
On 23 November 2007, the use and trade of pseudoephedrine in Mexico was made illegal as it was argued that it was extremely popular as a precursor in the synthesis of methamphetamine. Netherlands
Pseudoephedrine was withdrawn from sale in 1989 due to concerns about adverse cardiac side effects. New Zealand
In New Zealand, pseudoephedrine is currently classified as a Class B Part II controlled drug in the Misuse of Drugs Act 1975, making it illegal to supply or possess except on prescription.Pseudoephedrine, ephedrine, and any product containing these substances, e.g.
Increase of ectopic pacemaker activity can occur when pseudoephedrine is used concomitantly with digitalis. Antacids increase the rate of pseudoephedrine absorption, while kaolin decreases it. Mechanism of action
Pseudoephedrine is a sympathomimetic amine. Its principal mechanism of action relies on its direct action on the adrenergic receptor system. The vasoconstriction that pseudoephedrine produces is believed to be principally an α-adrenergic receptor response.Pseudoephedrine acts on α- and β2-adrenergic receptors, to cause vasoconstriction and relaxation of smooth muscle in the bronchi, respectively. α-Adrenergic receptors are located on the muscles lining the walls of blood vessels. When these receptors are activated, the muscles contract, causing the blood vessels to constrict (vasoconstriction). The constricted blood vessels now allow less fluid to leave the blood vessels and enter the nose, throat and sinus linings, which results in decreased inflammation of nasal membranes, as well as decreased mucus production. Thus, by constriction of blood vessels, mainly those located in the nasal passages, pseudoephedrine causes a decrease in the symptoms of nasal congestion. Activation of β2-adrenergic receptors produces relaxation of smooth muscle of the bronchi,  causing bronchial dilation and in turn decreasing congestion (although not fluid) and difficulty breathing. Other uses
There have been reports of off-label uses of pseudoephedrine for its stimulant properties. Long-distance truck drivers and athletes, for example, have reportedly used pseudoephedrine as a stimulant to increase their state of alertness/awareness.A study has also found that pseudoephedrine can reduce milk production in breastfeeding women.