Source: Melton ST, Kirkwood CK.
Anxiety Disorders. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells
BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic
Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=7989670.
Accessed May 26, 2012
- Anxiety disorder characterized by unexpected and repeated
episodes of panic attacks, which involve sudden intense fear that
develops for no apparent reason and triggers severe physical reactions.
- Genetic component
- Several biochemical theories have been postulated.
- Associated with activation of brainstem and basal ganglia
- May be abnormal activation of parahippocampal region and prefrontal
- 5-HT may have role in development of anticipatory anxiety.
- Affects 6 million Americans over age of 18.
- One-year prevalence rate: 2.7%.
- Twice as common in women as in men.
- Family history of panic disorder
- Stressful life events
- Psychological symptoms:
- Fear of losing control, going crazy, or dying
- Physical symptoms:
- Abdominal distress
- Chest pain or discomfort
- Dizziness or lightheadedness
- Choking feeling
- Hot flushes
- Shortness of breath
- Symptoms usually begin as unexpected panic attacks, followed
by at least 1 month of persistent concern about having another attack.
- Symptoms of panic attack peak within 10 minutes and usually
last 20–30 minutes.
- Many patients eventually develop agoraphobia, which is avoidance
of specific situations (e.g., being in crowded places) where they
fear attack might occur.
Means of Confirmation
- History of recurrent, unexpected panic attacks followed
- At least 1 month of concern about having another
- Worry about consequences of attacks
- Behavioral changes because of attacks
- During attack, there must be at least four physical symptoms
in addition to psychological symptoms.
- Complete resolution of panic attacks
- Marked reduction in anticipatory anxiety and phobias
- Elimination of phobic avoidance
- Resumption of normal activities
- Cognitive behavioral therapy (CBT) may be used alone for
patients who cannot or will not take medications.
- CBT typically initiated with pharmacotherapy if agoraphobia
- Educate patients to avoid:
- Drugs of abuse
- Figure 1: Algorithm for pharmacotherapy of panic disorder
- Selective serotonin reuptake inhibitors (SSRIs), tricyclic
antidepressants (TCAs), and benzodiazepines similarly effective;
50–80% of patients respond.
- SSRIs preferred in elderly patients and youth; benzodiazepines
second line in these patients because of potential for disinhibition.
- Drug choices (Table 1):
- First line: SSRIs,
- Second line: Alprazolam, clonazepam, clomipramine, imipramine.
- Alternatives: Phenelzine.
- Treat for 12–24 months before attempting discontinuation
over 4–6 months.
- Many patients require long-term therapy.
effect requires 4 weeks; some patients require 8–12 weeks.
- Start with low initial doses and titrate gradually to avoid
stimulatory side effects (anxiety, insomnia, jitteriness, irritability).
- Blocks panic attacks within 4 weeks
in most patients; maximal improvement requires 8–12 weeks.
- Venlafaxine XR
- 55–60% of
patients became panic-free on 75 or 150 mg.
- Second line except when rapid
- Do not use as monotherapy in patients with history of depression
or alcohol or drug abuse.
- May use concomitantly with ...