CHARLESTON, W.Va. -- The Southridge Walmart's sales of a cold and allergy medication that's also used to manufacture illegal methamphetamine have nearly tripled since January, according to data released by a Kanawha County task force this week. The Walmart at Southridge Centre sold 564 boxes of pseudoephedrine -- known under brand names such as Allegra-D, Claritin-D and Sudafed -- last January. Sales increased steadily throughout the year to a high of 1,653 boxes last month. Over the same eight months, total pseudoephedrine sales at all Kanawha County pharmacies dropped 18 percent, according to data from a new statewide tracking system called NPLEx. "It's like those folks shifted their business," said Dr. Dan Foster, chairman of the Kanawha County Commission's "Meth Task Force" that's investigating the illegal use of pseudoephedrine to make meth in clandestine labs. Kanawha County law enforcement agencies have seized more than 100 meth labs this year, a record number. Meanwhile, Kanawha pharmacies have sold more boxes of pseudoephedrine to customers on a per-capita basis than any county in West Virginia. Pseudoephedrine is a key meth-making ingredient. The Southridge Walmart sold 10 times more pseudoephedrine than its stores in Nitro and Quincy, according to the data. The nearby Target store, located along Corridor G in South Charleston, sold 123 boxes of pseudoephedrine last month. Bridget Lambert, executive director of the West Virginia Retailers Association, said the Walmart at Southridge has the highest overall merchandise sales volume in the county, so it stands to reason that the store would be the No. 1 seller of pseudoephedrine. "Just the volume of their customer base supports that," Lambert said. "It's the volume of people who go there and the store's location as to why they are where they are." Lambert added that the start of allergy season in August likely led to the spike in pseudoephedrine sales at the Southridge Walmart. "This is allergy season in West Virginia," she said. A Walmart spokeswoman would not comment Wednesday. Other Kanawha County stores with high sales included Rite Aids in Kanawha City (739 boxes in August), South Charleston (648 boxes) and on Charleston's West Side (592 boxes). Those sales numbers mostly held steady or declined slightly throughout the year. The NPLEx data also shows that the tracking system -- part of Gov. Earl Ray Tomblin's 2012 substance abuse bill -- has blocked an increasing number of pseudoephedrine sales at Kanawha County stores. In January, the electronic system blocked 217 boxes of the cold and allergy medication. Last month, NPLEx blocked 667 purchases, according to the data. "The thing that stands out blaringly to me is that the stores that do have the highest volume of traffic through their doors and are therefore asked to sell their customer base pseudoephedrine -- because that's where they go to get their cold and allergy remedy -- also have the highest number of blocked sales," Lambert said. "Those number do correlate with each other." In recent months, some Kanawha County law enforcement officials have criticized the statewide tracking system. Lambert said the latest numbers show NPLEx is working. "It's showing a lot of blocks," Lambert said. "NPLEx is doing its job." Kanawha County's total pseudoephedrine sales declined from 9,341 boxes in January to 7,653 boxes in August. Lambert predicted those sales would decline more rapidly this fall. Tomblin's bill sets monthly and yearly purchase limits for the drug. Many people who take pseudoephedrine for chronic allergies will meet their yearly limit this month, she said. Those customers can continue to buy the allergy medication if they get a doctor's prescription. State lawmakers have twice introduced legislation -- in 2011 and 2012 -- to require a prescription for pseudoephedrine, but legislators rejected both bills after drug industry and retail store representatives lobbied against the proposals. Last week, state Sen. Greg Tucker, D-Nicholas, said he would introduce a similar bill to make pseudoephedrine prescription-only. Oregon and Mississippi are the only two states that require a doctor's prescription to buy the cold and allergy medication. In West Virginia, pharmacies now keep pseudoephedrine products behind the counter, and customers must show a photo ID to purchase the drug. The task force plans to meet today at 9 a.m. at the Kanawha County Commission chambers. Reach Eric Eyre at firstname.lastname@example.org or 304-348-4869.