Anorexia nervosa and bulimia nervosa
are associated with altered levels of neurotransmitters, or chemical messengers in the brain.
This is particularly true of serotonin levels. It makes sense, then, that medications
developed to improve the function of neurotransmitters might be useful in the treatment
of eating disorders. Research over more than a decade has shown that medications can indeed be valuable
in the treatment of bulimia nervosa. More recent research has shown some promise
for the use of medications in treating anorexia nervosa as well.
SSRIs
Several different categories of psychiatric medications have been shown to be beneficial, but
the most widely studied are the SSRIs (Selective Serotonin Reuptake Inhibitors), the first and most
famous of which is fluoxetine, or Prozac. Other SSRIs include sertraline (Zoloft), paroxetine
(Paxil), fluvoxamine (Luvox), and citalopram/escitalopram (Celexa/Lexapro). All
raise the levels of serotonin available in parts of the brain. Venlafaxine (Effexor) is a related
drug that raises both serotonin and norepinephrine.
Though
popularly dubbed antidepressants, these drugs are used for a wide array of psychiatric diagnoses,
including anxiety, phobias, panic attacks, obsessive-compulsive disorder (OCD),
premenstrual dysphoria (PMS), post-traumatic stress disorder (PTSD), and impulse control disorders.
Many of these are common additional problems in patients with eating disorders and their families.
Anorexia Nervosa Medications
The initial goal in treating anorexia nervosa is the immediate restoration
of normal weight. This is urgent for physical health and is a crucial first step in psychological
recovery as well. Because people with anorexia nervosa are often sad and obsessional, it is logical
to hope that SSRIs might help. Although they are widely prescribed for this purpose, research
studies and the clinical experience of specialists both show that SSRIs DO NOT help low-weight patients
recover. Malnutrition appears to preclude their usual benefits.
A common adage holds that food is the medicine for anorexia nervosa.
Weight gain alone does often normalize mood in anorexia nervosa, but it can be hard to accomplish
and frequently requires hospitalization. Although certain psychiatric medications can cause weight
gain in the general population, none has had this effect with malnourished anorexic patients.
Recent exciting studies suggest that olanzapine (Zyprexa) and other medications in this class
may finally offer a drug that can help some low-weight anorexia nervosa patients.
Olanzapine lessens anxiety and obsessional thinking, and some anorexic patients find they feel
less paralyzed due to rigid thinking and behavior on this medication.
Olanzapine was originally marketed for schizophrenia, and although anorexia
nervosa is not a psychotic illness, there is certainly a delusional quality about feeling fat
when you are dangerously starved. Clinicians find that on olanzapine, some people with anorexia
nervosa are better able to grasp their situation and engage in treatment. Low-dose,
short-term use may facilitate that elusive transition from low to healthy weight for some people,
speeding the initial steps to recovery and sometimes averting hospitalization.
Once someone with anorexia nervosa has been successful
in restoring weight, maintaining those gains is the next hurdle. Unfortunately, immediate relapse
is common. Here's where fluoxetine enters the picture. Although this drug does
not help anorexia nervosa while the patient's weight is low, after the weight has been regained,
fluoxetine may significantly lessen the risk of relapse when used as part of a comprehensive treatment
program.
Bulimia
Nervosa Medications
The initial goal for bulimia nervosa is also symptom
management-in this case, stopping the binge/purge behaviors. Two treatments
have been documented by evidence-based scientific studies to have the best short-term success
rates. The first is cognitive behavioral therapy (CBT), and the second is high-dose
fluoxetine. Results are roughly comparable, with a suggestion that the two together may be better
than either one alone. However, since only a quarter of patients achieve symptom remission with these
approaches, further treatment is generally needed.
The
largest bulimia nervosa treatment trial in the world documented the benefits of high-dose fluoxetine.
This led to approval of fluoxetine by the FDA specifically for the treatment of bulimia nervosa.
Treatment is recommended to begin and continue at a dose of 60 mg. (The dose of 20 mg commonly
used for depression was no better than a placebo.) Bulimics benefit from fluoxetine regardless
of whether they are depressed. Moreover, if fluoxetine is going to be helpful, the results will
be apparent within 4 weeks. At least one study has shown this to be a successful initial approach
when used by primary care providers.
Are other
medications in the SSRI category also helpful? Published studies have now shown sertraline to benefit
bulimia nervosa at a higher dose range (150 mg). Although clinicians commonly do use other SSRIs
for this purpose, the data to assess their benefit and dosage is simply not available. Other classes
of antidepressant medications have also been shown to be helpful for the treatment of bulimia nervosa
and binge eating disorder.
Topiramate,
a totally different category of medication that was developed for treating epilepsy. It is now commonly
used for migraine headaches, and it is an exciting new option for patients with bulimia
nervosa, binge eating disorder, and simple obesity. Studies in
patients with these disorders show binge reduction, reduced preoccupation with eating, and weight
loss. Topiramate is used in relatively low doses (100-200 mg) for eating disorders and
weight loss. Gradual initial dose increases are required to avoid mental sluggishness.
Other side-effects are common but generally not serious. Patients who are taking hormones, including
oral contraceptives, may also require dose adjustment due to interaction with topiramate. Zonisamide
is another promising agent in this class.
Side-Effects
None of the medications described above have any
potential to be addicting. Often their use can be transitional, for several months to a year or two,
while recovery progresses and solidifies. However, since eating disorders frequently occur in patients
with depression or anxiety disorders, some of these people will benefit from longer-term use of
medication.
What about side-effects? As in all
medical care, doctors must weigh the risks of the treatment compared to the risks of the illness.
Fortunately, most of the side-effects of the medications used for eating disorders are relatively
minor, especially compared to the serious dangers of being anorexic or bulimic.
The most frequent side-effect of olanzapine is significant sedation, especially at the beginning.
The SSRIs may have mild initiation side-effects including nausea, headache, fatigue, or insomnia,
and less commonly agitation and over-excitement. These often pass within a week or two but they
may persist and should always be discussed with the physician. More enduring side-effects may
include vivid dreams, sweating, and a reduction in sexual interest or performance. Medications
that leave the body quickly (paroxetine, escitalopram, and venlafaxine) should be tapered off,
since sudden discontinuation can produce flu-like symptoms. Recently, the news media has focused
on whether teenagers respond as well and safely to SSRIs as adults do. A small percent of adolescents
(and a few adults) experience akathisia while taking common psychiatric drugs. Akathisia is a
kind of motor restlessness, a feeling of "jumping out of your skin," which should be reported to your
physician. In addition, concerns have been voiced about an increased risk of suicide among children
and teens taking SSRIs, even though overall suicide rates have dropped significantly as SSRI use
has become widespread. Government agencies are currently evaluating this question.
The exciting overview is that continuing progress is
being made in understanding the biology of anorexia nervosa and bulimia nervosa, as well as how medications
can help. Specialists in the field will be aware of the latest developments and the latest information
about the uses and benefits of available medications. The best outcome-ideally, complete recovery-is
most likely with an up-to-date and experienced eating disorder team working in firm alliance with
the patient and family.
Author
Diane Mickley, MD, FACP, FAED
