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PANIC DISORDER
(WITH OR WITHOUT AGORAPHOBIA)
Panic disorder responds
best to a combination of cognitive behavioural therapy (CBT) and antidepressant
medication. CBT helps patients learn to deal with intense anxiety and
feel more in control, while antidepressants help prevent panic attacks
from occurring.
SSRIs (Selective
Serotonin Reuptake Inhibitors)
The SSRIs are now considered the treatment of choice for panic and other
types of anxiety disorders, producing both anxiolytic as well as antidepressant
effects. Though generally better tolerated than older antidepressants,
SSRIs may provoke hyperstimulatory reactions, which may be related to
5-HT2 postsynaptic sensitivity that is present until the antidepressant
becomes effective. To avoid agitation, treatment should be initiated at
lower doses than are used for depression, and increased to regular doses
after one to two weeks. Adjunctive benzodiazepines may be used for two
to four weeks.
Newer cyclic agents
(nefazodone, venlafaxine) may also be effective in panic disorder, although
experience with these agents is limited.
Older Antidepressants
(TCAs/MAOIs)
These agents are useful (as are the SSRIs) in panic disorder with comorbid
depression. The main drawback with both the TCAs and the MAOIs is lack
of tolerance to their side effects. Up to 30% of patients feel jittery
on these medications, so that symptoms of anxiety may seem to worsen initially.
TCAs and MAOIs should also be used with caution in patients at risk for
suicide. If either drug class is used, initial doses should be low and
doses increased in small increments up to the therapeutic range.
Benzodiazepines
Alprazolam, clonazepam and lorazepam may be considered as alternatives
to antidepressants, with approximately 50% of patients responding to these
agents. Some clinicians favor alprazolam as their first choice because
its onset of action is more immediate and it is not associated with any
stimulatory reaction. Other clinicians favor clonazepam, which has a longer
half-life than alprazolam, requires less frequent dosing, and is less
problematic during withdrawal.
Panic attacks tend
to respond to higher doses of alprazolam than are required to treat generalized
anxiety disorder; however, patients usually respond within the first two
weeks of treatment and anticipatory anxiety is similarly reduced.
Lorazepam is not considered
to be as effective for panic disorder, however, it may be used sublingually
in panic attack.
Once symptoms are
controlled, the lowest effective dose should be used for maintenance therapy.
Drawbacks to alprazolam include the need for multiple daily dosing and
stopping treatment, which must be done over a period of several months,
especially if high doses have been used.
Other Anxiolytics
The anxiolytic buspirone has no efficacy in the treatment of panic disorder
(with or without agoraphobia) and should not be used.
Beta-Blockers
Comparisons between propranolol and benzodiazepines found the benzodiazepines
to be superior in the alleviation of panic attacks. Beta-blockers may,
however, offer added benefit in combination with a benzodiazepine.
Panic Disorder:
Outcome
After 6 to 10 years of treatment for panic disorder, studies indicate
that about 30% of patients are well; 40 to 50% are improved but symptomatic;
and the remaining 20 to 30% are unimproved or worse.
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