[NYAPRS Enews] Study: Psychiatric Polypharmacy Continues to Grow

[Harvey Rosenthal]

Psychiatric Polypharmacy Continues to Grow

By John Gever, Senior Editor, MedPage Today  January 04, 2010

 

Psychiatrists who prescribe drugs for their patients today usually give
more than one at a time, often with little scientific basis, researchers
said.

About 60% of patients with psychiatrist office visits leading to a drug
prescription received at least two medications in 2005-2006, according
to government survey data analyzed by Ramin Mojtabai, MD, PhD, MPH, of
Johns Hopkins University, and Mark Olfson, MD, MPH, of Columbia
University.

That was up from about 43% in 1996-1997 (P<0.001), the researchers
reported in the January Archives of General Psychiatry.

They also found that 33% of prescription-associated visits led to three
or more medications in the latter period, compared with 17% nine years
earlier (P<0.001).

These multiple combinations sometimes involved drugs within the same
class -- two or more antidepressants for depressed patients, for example
-- but more often drugs of different classes.

Gaining in popularity during the study period were combinations of
antidepressants and antipsychotic drugs, with an adjusted odds ratio of
1.96 (P<0.001) for each year during the study period.

"While some of these combinations are supported by clinical trials, many
are of unproven efficacy," Mojtabai and Olfson wrote. "These trends put
patients at increased risk of drug-drug interactions with uncertain
gains for quality of care and clinical outcomes."

Jeffrey Lieberman, MD, of Columbia University, who was not involved with
the study, told MedPage Today in an interview that the findings were
"disturbing and not entirely surprising."

He said earlier studies as well as his own experience had suggested that
psychiatric polypharmacy is a growing phenomenon.

The researchers based their findings on data from the CDC's ongoing
National Ambulatory Medical Care Survey program. The analysis covered
13,079 psychiatrist office visits over the 11 years from 1996 through
2006.

Drug prescriptions and other survey data were provided by participating
physicians' offices after each visit. Mojtabai and Olfson classed the
reported drugs into four categories: antidepressants, antipsychotics,
mood stabilizers, and sedative-hypnotic drugs. Benzodiazepines and other
drugs often used for anxiety disorders were included in the last
category.

Overall, the percentage of psychiatrist office visits leading to one or
more drug prescriptions increased from 73.1% in 1996-1997 to 86.2% in
2005-2006 (P<0.001), Mojtabai and Olfson found.

While the median number of prescriptions in the earlier period was one,
it had risen to two by 2005-2006. The mean increased to 1.99, from 1.42
in the mid-1990s (P not reported).

In addition to the passage of time, other factors significantly
associated with psychiatric polypharmacy included the following (all
odds ratios adjusted for demographics and clinical characteristics of
visits):

    * Age 45 to 64: OR 1.31 relative to younger age (P<0.001)

    * Female sex: OR 1.30 relative to men (P<0.001)

    * Medicaid patient: OR 1.77 relative to private insurance (P<0.001)

    * Medicare patient: OR 1.73 relative to private insurance (P<0.001)

    * Multiple psychiatric diagnoses: OR 1.61 (P<0.001)

Single diagnoses of major depression, bipolar disorder, anxiety
disorder, or schizophrenia were also each significantly associated with
multiple prescriptions, with adjusted odds ratios ranging from 1.57 for
anxiety to 3.79 for bipolar disorder (all P<0.001) relative to patients
with other diagnoses.

Racial minorities were less likely to receive multiple prescriptions
than were whites, as were new patients relative to returning patients.

Mojtabai and Olfson found that antidepressants were most often
prescribed with sedative-hypnotic drugs, accounting for 22% of all
visits in which an antidepressant was prescribed in 1996-1997 and 27% of
those in 2005-2006 (not significant).

Some 10% of visits involving antidepressants in the earlier period also
included an antipsychotic prescription, which increased to 16% in 2005
to 2006 (P<0.001).

Adding a second (or third) antidepressant also doubled in frequency,
from 8% to 16% of visits leading to an antidepressant prescription.

Antidepressants were the most commonly prescribed psychiatric
medications at both time points, involved in more than 60% of visits
with prescriptions.

Combinations not involving antidepressants also increased in frequency,
but Mojtabai and Olfson -- who used a strict P<0.01 standard for
statistical significance -- reported that those increases were not
significant.

For example, the frequency of antipsychotic and sedative-hypnotic drug
combinations increased by about half during the study period, from 8% of
antipsychotic-associated visits to 12%, with a P value of 0.02.

"Significant time trends appeared to be mainly limited to concomitant
prescription of two or more antidepressants or antipsychotics as well as
combinations of antipsychotics and antidepressants," the researchers
wrote.

In their discussion of the results, they took a dim view of these
trends.

They noted that there was some evidence that combining antidepressants
can improve the efficacy. But they also indicated that such combinations
raise the risk of adverse effects.

"Some antidepressants inhibit cytochrome P450 enzymes and thus impact
the metabolism of other psychotropic medications, including other
antidepressants," they pointed out in the report.

"A further potential complication associated with overuse of
antidepressant medications is the risk of emerging manic symptoms in
susceptible depressed patients and acceleration of mood cycles in
patients with bipolar disorder," they wrote.

They expressed similar concerns about combinations of antidepressants
and antipsychotics.

Lieberman said there was little evidence to justify multiple drugs for
treating depression.

"Are there studies showing that two drugs or three drugs are better than
one drug? The answer is no," he said. "There's a potential rationale but
it's not all that compelling."

Mojtabai and Olfson indicated that the reasons for the increase in
polypharmacy were unclear, but suggested that "a change in the style of
psychiatric practice" may be been at least partly responsible.

"Some psychiatrists may be placing greater emphasis on symptom reduction
while lowering their concerns over the number of medications required to
achieve this clinical goal," the researchers wrote.

In a telephone interview, Lieberman said one factor may be that doctors
are "frustrated by the limitations in effectiveness of existing
medications," tempting them to simply pile on additional drugs.

Consequently, he said, "they improvise with what might be called
innovative psychopharmacology, or trial and error."

He said marketing may also be an influence. Although drugmakers aren't
permitted to tout unapproved combinations, their advertising for
approved indications may have a "carryover effect" in the minds of
physicians as well as patients, Lieberman said.

Lieberman said increased education and perhaps restrictions on drug
formularies -- especially in the Medicare and Medicaid programs -- could
help rein in the polypharmacy practice, though he noted that limiting
access to medications was unpopular with both physicians and patients.

 

Primary source: Archives of General Psychiatry

Source reference:

Mojtabai R, et al "National trends in psychotropic medication
polypharmacy in office-based psychiatry" Arch Gen Psych 2010; 67: 26-36.

 

http://www.medpagetoday.com/Psychiatry/GeneralPsychiatry/17785 





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