Chapel Hill, N.C. — A team of state inspectors was at a Chapel Hill nursing home Thursday to determine why nine Alzheimer's patients there tested positive for strong pain-control drugs that they weren't supposed to be receiving.

Two pharmacists and a registered nurse from the Division of Health Service Regulation's Nursing Home Licensure Section were monitoring the health and welfare of residents at Britthaven of Chapel Hill, at 1716 Legion Road, and were gathering information about drugs administered to them, said Jim Jones, a spokesman for the state Department of Health and Human Services.

Three Alzheimer's patients were taken to UNC Hospitals on Sunday after nursing home managers said they were acting unusual. Hospital officials then contacted police, DHHS and Britthaven managers to express concerns about the patients' situation.

A Chapel Hill police report states the concerns revolved around possible over-medication of the patients.

Jeff Horton, who heads the Division of Health Service Regulation, said Thursday that the patients were lethargic, and subsequent blood tests showed "what looked like drugs in their system (that) they weren't prescribed."

Britthaven officials then tested all of the approximately 25 patients in the Alzheimer's unit for drugs. Six tested positive for opiates, a class of controlled substances often used for pain management, officials said. Three of them were hospitalized as a precaution, officials said.

"It didn't seem like we knew how (the drugs) got there, so we'd be looking to see if there's anything from the facility's standpoint that may have contributed to this," Horton said.

Dr. Allen Mask of WRAL's Health Team said side-effects of opiates include sedation, drowsiness, nausea and constipation.

"In high enough doses, it can cause respiratory depression, cause you to stop breathing," Mask said.

One of the first three patients hospitalized, 84-year-old Rachel Holliday, died Tuesday. None of the other five hospitalized patients has returned to Britthaven, but it's unclear if they were still in the hospital Thursday.

On Wednesday, the nursing home tested all staff members of the Alzheimer's unit for drugs and sent them home, officials said. Other staff took over management of the unit and began monitoring patients around the clock.

"I don't want the public to rush to judgment about the facility," Horton said. "They did report it right off the bat. They've been open with us, and we're going to conduct the investigation," Horton said.

Jones said the three-member team left Britthaven Thursday evening and were awaiting the results of lab tests to determine what medications could have contributed to the opiates found in the patients. The team felt confident the residents at the nursing home are safe, he said.

An official of Kinston-based Britthaven, which operates nursing homes in North Carolina, Kentucky and Virginia, met for two hours Wednesday with Chapel Hill police to discuss the situation.

Police said they are waiting to see what DHHS inspectors find before deciding whether a criminal investigation is necessary.

Thirty-three of Britthaven's facilities in North Carolina are rated on a federal nursing home Web site. Four scored the highest possible rating, while seven, including Britthaven of Chapel Hill, scored the lowest-possible rating. The Chapel Hill facility was the only one designated as having a history of persistent poor quality of care.