'Rookie' antidepressant users at risk for poor adherence

OB/GYN News, Nov 15, 2005 by Doug Brunk

SAN DIEGO -- Patients who are new to antidepressant therapy are at the greatest risk of discontinuing therapy, and that risk is greatest at the time of first prescription refill, Mark Vanelli, M.D., reported during a poster session at the American Psychiatric Association's Institute on Psychiatric Services.

"The implication is that we need to spend more money and time on patient education, and less on effective physician prescribing behavior," said Dr. Vanelli, chief medical officer for Burlington, Mass.--based Adheris Inc., a provider of patient adherence intervention programs.

Physicians "need to emphasize the length of time patients need to be on antidepressant therapy," he said in an interview. "Six months or more is common. They probably also need to talk about possible side effects and how they can be managed, to help patients anticipate the side effects they may have, such as insomnia or agitation.

"It's also important to connect medication use with helping them solve a problem in their life that they're going to be able to fix. That's often connecting with their chief complaint."

Using records from 1,157 pharmacies in the United States, Dr. Vanelli and his associates identified 211,565 patients who filled a prescription for fluoxetine, sertraline (Zoloft), paroxetine (Paxil), venlafaxine (Effexor), citalopram (Celexa), or escitalopram (Lexapro) from Oct. 1, 2003 through March 31, 2004. They defined "rookies" as patients who had never used an antidepressant in the 180 days prior to the index fill. "Veterans" were defined as patients who had a history of antidepressant use in the preceding 180 days.

The investigators followed the patients for 360 days to calculate the number of days to therapy discontinuation. Of the 211,565 patients, 74% were female, and the mean age was 51. More than one-third of those in the sample (37%) were rookies.

The mean number of days to medication discontinuation was 67 for rookies and 184 for veterans. The likelihood of discontinuing therapy after the initial fill, which was 30-45 days after the onset of therapy, was about 40% for rookies and 20% for veterans.

Proportional hazards model analysis revealed that veterans were 37% less likely to discontinue therapy, compared with their rookie counterparts.

BY DOUG BRUNK

San Diego Bureau