Gov. Ted Kulongoski (search) on Tuesday signed legislation that will make Oregon (search) the first state to require prescriptions for cold and allergy medications that can be converted into methamphetamine (search).

The requirement applies to any medication containing pseudoephedrine (search), the key ingredient in the highly addictive street drug.

Kulongoski said he was aware of inconveniences that might arise from having to get prescriptions for commonly purchased remedies but said pharmaceutical companies already are producing replacement remedies that don't contain pseudophedrine.

The bill sailed though both houses of the Legislature, opposed by only a handful of lawmakers who said it would be an inconvenience to their constituents to need prescriptions for such common drugs as Sudafed and the Claritin D. Schering-Plough Corp (search)., based in Kenilworth, N.J., makes Claritin-D and five other over-the-counter drugs that contain pseudoephedrine. New York-based Pfizer Inc. (search) makes Sudafed and other medicines with pseudoephedrine

Backers of the bill countered that medicines containing phenylephrine (search), which cannot be converted to meth, will remain readily available.

The state Board of Pharmacy has until next July to implement the new prescription requirement but board executive director Gary Schnabel said it could be in place within three months.

Patients will be allowed up to five refills in a six-month period, Schnabel said.

Tom Holt, executive director of the Oregon State Pharmacy Association (search), said he thinks the law will drive the pseudoephedrine-containing cold and allergy pills out of the market within a year or two.

Oregon and several other states already require consumers to show identification and sign a log when obtaining these cold and allergy medicines from pharmacies, and Congress is moving toward similar restrictions.

While increasing amounts of methamphetamine comes in from Mexico (search), bill supporters say it could sharply reduce the number of home meth labs where the chemicals used in the process can pose severe health problems.