Latest diabetic medications more costly, but users have fewer hospital visits

Diabetics who were prescribed newer medications to control their illness were more likely to take these drugs as instructed than were other patients who were prescribed drugs that have been on the market for several decades.

A new study suggests that patients on the newer medications had a slightly lower risk of hospitalization because of diabetes-related complications. They also spent between $920 and $1,760 less on annual total healthcare costs.

The researchers analyzed more than three years' worth of medical records' data on patients who took thiazolidinediones (TZDs) or either metformin or a sulfonylurea to control their diabetes. TZDs (pioglitazone and rosiglitazone, brand names Actos and Avandia, respectively), were approved by the Food and Drug Administration in the late 1990s. Metformin and sulfonylureas have been on the market for more than 50 years.

"Taking a TZD as instructed was the strongest predictor of a reduced risk of hospitalization and decreased healthcare costs in this group of patients," said Rajesh Balkrishnan, the study's lead author and the Merrell Dow professor of pharmacy at Ohio State University.

The issue is that TZDs can be 10 times more expensive than the older diabetes drugs, Balkrishnan said.

"There are a lot of new medications on the market for treating diabetes," Balkrishnan said. "Although some of these newer drugs are more expensive, that extra expense is made up for by a reduction of cost in other aspects of healthcare use."

The study appears in a recent issue of the journal Current Medical Research and Opinion.

The researchers collected information on 3,191 adults enrolled in the North Carolina Medicaid program, which covers all medical and prescription costs of its enrollees. All of the participants had Type 2 diabetes and started medications for the disease between July 2001 and December 2003.

The enrollees were divided into two groups based on the type of drug their physicians prescribed: 1,774 took a TZD, while 1,417 took either metformin or a sulfonylurea. The researchers collected information on total healthcare expenditures and hospitalization rates for all patients through December 2004.

A person with Type 2 diabetes is insulin resistant, meaning that the cells in his body can't correctly use the insulin it makes; as a result, blood sugar levels remain high. TZDs make cells in the body more sensitive to insulin, while metformin lowers blood sugar levels and sulfonylureas boost pancreatic insulin production.

Metformin and the sulfonylureas are available in generic forms. A generic medication contains the same ingredients and has the same effect on the body as its brand-name counterpart, but typically sells for much less. The pharmaceutical companies that make TZDs still hold the patents for these drugs, so generic versions aren't yet available.

A brand-name TZD may cost $100 a month, while a prescription for a generic sulfonylurea or metformin may cost as little as $10 a month, Balkrishnan said.

The researchers compared how likely patients were to take their medications on time by collecting information on how often they refilled their prescriptions. The researchers assumed that a prescription filled meant that the previous prescription had been taken.

Results showed that patients taking TZDs were more likely to refill their prescriptions on time.

"We're not sure why that was so," Balkrishnan said. "It could be that the TZD helped get symptoms under control faster."

The researchers also calculated total healthcare costs for both groups. Total healthcare costs included hospitalizations, emergency department visits, outpatient physician visits, use of anti-diabetic medications and the use of medications for any other condition.

Overall, the participants who took a TZD spent an average of $76 to $150 less per month on total healthcare costs, which adds up to about $920 to $1,760 less annually. The patients taking a TZD spent about $836.34 on monthly healthcare costs, compared to $983.13 per month for patients taking metformin and $913.11 per month for patients taking sulfonylureas.

The patients who were prescribed TZDs were about 10 percent less likely to be hospitalized than were the patients taking either of the other two older drugs.

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