The investigators, from the Government Accountability Office, said Medicare officials had been slow to recognize and act on the evidence of abuse, which is to be presented at a Senate hearing on Tuesday.
“Our analysis found that about 170,000 Medicare beneficiaries received prescriptions from five or more medical practitioners” for 14 types of drugs that are frequently abused, said Gregory D. Kutz, director of forensic audits and special investigations at the accounting office.
The medications were obtained through Part D of Medicare, which provides coverage for prescription drugs. The drugs most commonly abused by Medicare beneficiaries included powerful prescription painkillers like oxycodones and hydrocodone products. Oxycodones include OxyContin and Percocet.
In one case described in the report, a Medicare beneficiary in Georgia received a 150-day supply of oxycodone in just 27 days by obtaining seven prescriptions from four doctors. Over the course of a year, the woman received prescriptions for a total of 3,655 oxycodone pills (a 1,679-day supply) from 58 different prescribers, and she filled them at more than 40 pharmacies.
In another case, a California man received prescriptions for a total of 1,397 fentanyl patches and pills (a 1,758-day supply) from 21 different prescribers in a year. In a third case, a Texas beneficiary received prescriptions for a total of 4,574 hydrocodone pills (a 994-day supply) from 25 different doctors.
Senator Thomas R. Carper, Democrat of Delaware, said: “Federal dollars intended to address the health needs of the elderly and the poor are instead being used to feed addictions or to pad the wallets of drug dealers. This is clearly unacceptable.”
Mr. Carper called the hearing as chairman of a Homeland Security and Governmental Affairs subcommittee.
The accounting office said prescription drug abuse threatened the health of beneficiaries and increased costs to taxpayers. “Medicare beneficiaries may be seeking several medical practitioners to support and disguise an addiction” or to obtain drugs that they can sell to others, the report said.
In many cases, doctors said they did not know that their patients were receiving prescriptions from other physicians.
When told that one of his Medicare patients had received prescriptions for a 994-day supply of hydrocodone pills from 25 different prescribers in one year, a Texas doctor told investigators that “it was medically unnecessary and possibly dangerous to consume the amount of narcotics obtained by the beneficiary.”
The auditors recommended that Dr. Donald M. Berwick, administrator of the federal Centers for Medicare and Medicaid Services, consider limiting patients who abuse prescription drugs to one prescriber or one pharmacy.
Medicare officials said they were reluctant to make that change. While acknowledging possible overuse of drugs by some beneficiaries, they said they did not want to jeopardize patients’ access to care.
“High utilization of pain medications is not necessarily an indication of abuse, but could be an indication of poorly coordinated care in the treatment of pain symptoms,” the Medicare agency said in a written response to the accountability office.
The Medicare drug benefit is managed by private insurance companies under contract with the government.
Jonathan D. Blum, deputy administrator of the Centers for Medicare and Medicaid Services, said prescriptions for painkilling medications known as opiates had increased sharply. Medicare drug plans provided nearly 57 million opiate prescriptions last year, up from nearly 46 million in 2007, an increase of 24 percent, he said.
Mr. Blum said greater use of electronic health records and the electronic transmission of prescriptions to drugstores could reduce fraud and abuse by making it easier to keep track of patients’ medication history. In addition, he said, insurers could step up the review of claims to identify patterns of “gross overuse or inappropriate or medically unnecessary care.”
In a memorandum to insurers last week, Cynthia G. Tudor, director of Medicare’s drug benefit group, asked them to suggest how Medicare could “more successfully exert control over payment for inappropriate overutilization of drugs.”
Even if an insurer detects misuse of prescription drugs and takes action to stop it, a beneficiary can often get medications by enrolling in a prescription drug plan offered by another insurance company.
Medicare officials told investigators that prescription drug plans could not share information on beneficiaries. As a result, the report said, patients can bypass restrictions “merely by switching prescription drug plans.”