Medical Management Of Anorexia Nervosa And Bulimia Nervosa

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Although this research strongly suggests that HRT is not the treatment of choice, one cannot ignore studies like the one published in the November/December 1998 issue of Eating Disorders Review entitled "Dual Hormone Therapy Prevents Bone Loss." According to Baylor researchers, after one year, women who were amenorrheic due to disordered eating or excessive exercising (a condition called hypothalamic amenorrhea) and who received an estrogen-progestin combination had significantly more mineral in their total skeletons and lower spines than the other groups. It is speculated that the estrogen-progestin combination may mimic the hormonal pattern of a normal menstrual cycle and may be warranted until medical care can improve well-being and until normal menstruation returns.

Physicians should also consider prescribing alendronate (Fosa-max®), a recently approved form of bisphosphonate. Differing from estrogen, alendronate has been shown to positively affect postmenopausal osteoporosis by inhibiting bone resorption. Alendronate can be used either in addition to estrogen or in cases where estrogen treatment is not clinically appropriate. However, alendronate often causes gastrointestinal side effects that can be quite distressing to patients with eating disorders.

Sodium fluoride, calcitonin, and other proposed treatments such as those related to insulinlike growth factors may be effective for treating bone deficiency, but more research is needed to demonstrate their effectiveness.

Clearly, the treatment protocol for eating disordered patients with amenorrhea has not been established. It would be wise at this point to vigorously treat patients whose deficiencies have been long-lasting or severe (i.e., two standard deviations below age-matched norms) using a variety of methods, including HRT and alendronate. Those with less severe deficiencies may be treated by more moderate methods, such as calcium and vitamin D supplements, possibly with the addition of an estrogen-progestin combination if necessary.

BULIMIA NERVOSA

Unlike anorexia nervosa, most of the medical complications of bulimia nervosa directly result from the different modes of purging utilized by these patients. It is functionally more understandable if the complications inherent to a particular mode of purging are reviewed separately.

SELF-INDUCED VOMITING

An early complication resulting from self-induced vomiting is parotid gland enlargement. This condition, referred to as sialadenosis, causes a round swelling near the area between the jawbone and the neck and in severe cases gives rise to the chipmunk-type faces seen in chronic vomiters. The reason for parotid swelling in bulimia has not been definitively ascertained. Clinically, in bulimic patients, it develops three to six days after a binge-purge episode has stopped. Generally, abstinence from vomiting is associated with the ultimate reversal of the parotid swelling. Standard treatment modalities include heat applications to the swollen glands, salivary substitutes, and the use of agents that promote salivation, most commonly tart candies. In the majority of cases, these are effective interventions. For stubborn cases, an agent such as pilocarpine, may promote shrinking of the size of the glands. Rarely, parotidectomies (removal of the glands) have to be performed to alleviate this problem.

Another oral complication of self-induced vomiting is perimyolysis. This refers to erosion of the enamel on the surface of the teeth near the tongue, which is presumably due to the presence of the acid in vomit that passes through the mouth. Patients who induce vomiting at a minimum frequency of three times per week for a year will show erosion of tooth enamel. Vomiting may also cause an increased incidence of dental cavities, inflammation of the gums, and other periodontal diseases. At the same time, a frequently voiced complaint of extreme sensitivity to cold or hot food is a result of exposed teeth dentin.

The proper dental hygiene for these patients is somewhat unclear. However, it is obvious that they need to be cautioned against immediately brushing their teeth after vomiting because it will hasten the erosion of the weakened enamel. Rather, rinsing with a neutralizing agent, such as baking soda, has been recommended. Patients should also be encouraged to seek regular dental treatment.

A potentially more serious complication of self-induced vomiting is the damage it causes to the esophagus. These patients complain of heartburn due to the stomach acid's irritant effect on the esophageal lining, which causes a condition known as esophagitis. Similarly, repeated exposure of the esophageal lining to the acidic stomach contents can result in the development of a precancerous lesion referred to as Barrett's esophagus. Another esophageal complication of vomiting presents as a history of vomiting bright-red blood. This condition is known as a Mallory-Weiss tear, which is due to a tear in the mucosal lining.

Aside from encouraging the cessation of vomiting, the approach to complaints that involve dyspepsia (heartburn/sour taste in the mouth) or dysplagia (difficulty swallowing) is comparable to that utilized in the general population with these complaints. Initially, together with the recommendation to cease vomiting, the simple suggestion of antacids is offered. The second level of intervention involves drugs known as histamine antagonists, such as cimetidine, plus an agent that induces gastric contractions such as cisapride, to strengthen the gate between the stomach and the esophagus, which in turn prevents acidic contents from refluxing back and irritating the esophagus. Proton-pump-inhibitors that inhibit acid secretion in the stomach, such as omeprazole, are the third line and most potent therapy for resistant cases. Generally, this will suffice for most patients and resolve their symptoms. The important point to be aware of is the potential harmful implications of severe and stubborn dyspepsia. Since resistant cases may be harbingers of a more serious process, referral to a gastroenterologist should be recommended so that an endoscopy can be performed and a definitive diagnosis made.

One other important condition with regard to the esophagus is Boerhaave's syndrome, which refers to a traumatic rupture of the esophagus due to forceful vomiting. It is a true medical emergency. Patients with this condition complain of the acute onset of severe chest pain that is worsened by yawning, breathing, and swallowing. If this condition is suspected, prompt referral to an emergency room is indicated.

Lastly, vomiting causes two main electrolyte disorders: hypo-kalemia (low potassium) and alkalosis (high blood alkaline level). Either of these, if severe enough, can result in serious cardiac arrhythmia, seizures, and muscle spasms. It does not suffice to place these patients on supplemental potassium, because the body cannot absorb the potassium. The beneficial effects of supplemental potassium are nullified unless there is restoration of the volume status either with intravenous saline or oral rehydration solutions such as Pedialite or Gatorade. One final point about self-induced vomiting: some bulimics use ipecac to induce vomiting. This is dangerous because it is toxic to the heart. Because of ipecac's long elimination time, repeated ingestion can result in potentially fatal cumulative doses. Heart failure and arrhythmia can result.

LAXATIVE ABUSE

If the mode of purging is through laxative abuse, there are also potential problems with potassium and acid-base aberrations. It is worth telling patients that laxatives are a very ineffective method to induce weight loss because caloric absorption occurs in the small bowel and laxatives affect the large bowel by promoting the loss of large volumes of watery diarrhea and electrolyte depletion.

The main body system affected by laxatives is the colorectal area. This information refers strictly to stimulant laxatives that contain senna, cascara, or phenolphthalein and directly stimulate colonic activity. These types of laxatives, if used in excess, damage the colonic neurons that normally control gut motility and contractions. The result is an inert, noncontractile tube referred to as the "cathartic colon syndrome." This causes significant problems with fecal retention, constipation, and abdominal discomfort. Loss of colonic function can become so severe that a colectomy (surgery) is needed to treat intractable constipation.

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It is crucial to identify laxative abusers early in the course of treatment, before permanent colonic damage has occurred, so that they can be encouraged to seek the assistance of a physician who is adept at withdrawing patients from stimulant laxatives. Laxative withdrawal can be an extremely difficult situation, which is made worse by fluid retention, bloating, and swelling. The mainstays of treatment involve educating patients that it may take weeks to accomplish restoration of normal bowel habits. Patients need to be advised about the importance of ample fluid intake, a high-fiber diet, and judicious amounts of exercise. If constipation persists, a glycerin suppository or a nonstimulating osmotic laxative (works by shifting fluids), such as lactulose, may be useful. Most patients are successfully detoxed with this type of program, but patience is necessary to endure the transient bloating that will resolve in one to two weeks with salt restriction and leg elevation. Progressive abdominal pain, constipation, or distention warrants an abdominal X ray and further evaluation.

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