 Treatment Algorithms --
June 2008
 In This Issue...
Introduction:
Generalized anxiety disorder (GAD) is a common psychiatric
condition characterized by excessive anxiety and unrealistic worry lasting for
a period of several months, often accompanied by comorbid depression. More than
11 million people in the United States will suffer GAD in 2008. Patients are typically
treated first by primary care physicians (PCPs), who then sometimes refer more
difficult patients to psychiatrists, who tend to see a greater number of
moderate to severe anxiety patients than do PCPs. The American Psychiatric
Association (APA) does not have established treatment guidelines for GAD, but
early lines of treatment for GAD center on the use of benzodiazepines for
somatic symptom relief or selective serotonin reuptake inhibitors (SSRIs), such
as Forest’s Lexapro (escitalopram), paroxetine (GlaxoSmithKline’s Paxil,
generics), GlaxoSmithKline’s Paxil CR (paroxetine CR), or sertraline (Pfizer’s
Zoloft, generics), for somatic and psychic symptom relief. Somatic symptoms are
typically insomnia and muscle tension, while psychic symptoms consist of worry
and apprehension.
A variety of other classes exist to treat anxiety, and they are
used when patients do not respond to initial treatment, cannot take a
medication with addictive potential, or desire a change in medication owing to
side effects. The selective norepinephrine-serotonin reuptake inhibitors
(SNRIs), consisting of Eli Lilly’s Cymbalta (duloxetine), Wyeth’s Effexor XR
(venlafaxine XR), and venlafaxine IR (Wyeth’s Effexor, generics), fall
primarily into this group of later-line agents and are indicated for the same
type of patients as the SSRIs. Other classes used to treat GAD patients include
antiepileptic drugs, bupropion (GlaxoSmithKline’s Wellbutrin/Wellbutrin SR,
generics), modified cyclics, tricyclic agents, and heterocyclic agents.
Atypical antipsychotics, such as AstraZeneca’s Seroquel (quetiapine),
Bristol-Myers Squibb/Otsuka’s Abilify (aripiprazole), and Eli Lilly’s Zyprexa
(olanzapine), are used sparingly in anxiety treatment, but the recent move by
AstraZeneca to file a supplementary new drug application with the FDA for
Seroquel XR in the treatment of GAD underscores the fact that many companies
will look toward GAD as an indication in which to expand their atypical antipsychotic
franchises over the next few years. Other emerging therapies include two novel-mechanism
drugs launching for major depression in 2009: agomelatine, a melatonin and HT2C
receptor antagonist under development by Novartis, and GSK-372475, a triple
reuptake inhibitor from NeuroSearch/GlaxoSmithKline. These novel-mechanism
agents will expand the GAD market, but several compounds, including Effexor XR,
Paxil CR, and Risperdal, face patent expiration and will have the opposite
effect on the GAD market.
Questions Answered in This Report:
- Lines of therapy: While there are no guidelines from the
American Psychiatric Association for GAD treatment, SSRIs and benzodiazepines
dominate first-line treatment, and SSRIs dominate further lines. How much of
early-line patient share is devoted to SSRIs versus benzodiazepines? In which
lines of treatment do physicians turn to Effexor XR and Cymbalta?
- Pathways to key therapies: SSRIs lead all classes in
patient share across all three lines of therapy, and Lexapro leads all SSRIs
across all three lines of therapy, but not by a great margin over generic SSRIs.
To what extent do patients resort to in-class SSRI switching for symptom
relief? How do the pathways to each drug class in GAD treatment differ?
- Physician behavior: The pharmaceutical armamentarium for anxiety
treatment is varied, with SSRIs and benzodiazepines the most widely used, but SNRIs,
AEDs, and atypical antipsychotics all have their niches. What are the
attributes that trigger a physician to choose Lexapro over Effexor XR, and vice
versa? What are the main triggers for practicing physicians to move a
patient to a drug other than a benzodiazepine? Do physicians change dose before
switching or adding therapy?
- Forecast: Surveyed PCPs predict they will increase their
use of SSRIs first line in anxiety patients; both psychiatrists and PCPs
predict that they will increase their use of SNRIs as first-line treatment. How
will psychiatrists and PCPs utilize current and emerging agents in lines of
therapy over the next two years? Will atypical antipsychotic use increase in
earlier lines of therapy? Is there a favored atypical antipsychotic agent for
anxiety treatment?
Includes:
Primary research: Quantitative results from our
survey of 154 physicians (79 psychiatrists and 75 PCPs):
- Physician opinion on how drug use differs by patient severity.
- Most influential drug attributes when physicians choose between
agents.
- Anticipated changes in the line of therapy in which physicians
use key agents.
Primary patient-level data: Quantitative findings
from our analysis of data covering 55 million lives from more than 80
geographically diverse U.S. health plans:
- Quantified lines of therapy analysis showing exact share of each
agent in each line of therapy, including rate of progression between lines and
length of time patients are on each line.
- Progression flowcharts through one year of treatment for newly
diagnosed patients receiving each of the following first-line agents: benzodiazepines,
Lexapro, sertraline, citalopram, paroxetine IR, other antiepileptics,
fluoxetine, non-benzodiazepine GABA-A agonists, bupropion, Effexor XR,
buspirone, Paxil CR, modified cyclics, Cymbalta, tricyclic agents, mirtazapine,
Seroquel, Risperdal, venlafaxine IR, Zyprexa, Lyrica, Geodon, fluvoxamine.
- Flowcharts tracking the preceding therapy patterns for patients
taking each of the following key therapies: benzodiazepines, Lexapro,
sertraline, citalopram, paroxetine IR, Paxil CR, fluoxetine, Effexor XR,
venlafaxine IR, Cymbalta, mirtazapine, buspirone, Lyrica, Seroquel, Abilify,
Invega.
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