The governor of US state Mississippi, Haley Barbour, has signed a bill restricting the use of over-the-counter (OTC) drugs containing pseudoephedrine.

Pseudoephedrine is a sympathomimetic drug of the phenethylamine and amphetamine chemical classes, which is used as a nasal/sinus decongestant and stimulant.

The drug is also, however, a important ingredient in methamphetamine, a highly addictive and dangerous street drug that increases levels of dopamine and norepinephrine in the brain.

The statute, House Bill 512 received overwhelming support and passed through legislature within a week. The new rules will take effect from 1 July and will require a doctor’s prescription for products containing pseudoephedrine, including popular nasal decongestants such as Sudafed and Advil Cold and Sinus.