CLINICAL 'AND RESEARCH ·REPORT
Syndrome of
Inappropriate
Antidiuretic
Hormone (SIADH)
in an 80-Year-Old
Woman Given
Clomipramine

Barbara R. Sommer, M.D.

The author describes the syndrolne ofi nappropriate antidiuretic bor1none, lvith serUIn sodiu111 decreasing from 137 l1zEq/L
to 122 lnEq/L in an 80-year-old WOlnan
prescribed clolnipl"Q1nine. Tbe patient's
delirium and serum soditl1n lvere slow to
nonnalize, prolonging IJer hospital stay
and delaying treatlnent ofher depression.
(Am] Geriatr Psychiatry 1997; 5:268-269)

A

lthough tricyclic antidepressants have
been known to cause the syndrome
of inappropriate antidiuretic hormone
(SIADH), 1 there are currently few reports
of SIADH in geriatric patients taking tIle
antidepressant clomipramine, and these reports describe resolution within 3 days.2--'
We describe the case of an SO-year-old
woman whose delirium and low serum sodium were slow to normalize even after
clomipramine was discontinued. Her
symptoms had been interpreted by 11er
family as worsening of depression.

Mrs. A. was hospitalized for the evaluation and
treatment of severe depression. During the
previous 2 years, she had lost all motivation,
had let long-standing friendships go, and had
complained of an exacerbation of chronic nausea, without vomiting, which had been evaluated previously as having no medical etiology.
She suffered from anhedonia, guilty feelings,
fitful sleep, and anorexia, with a 13-pound
weight loss over the previous year. Furthermarc, she was isolative and withdrawn, and
she often thought of joining her dead husband
in heaven. Attempted antidepressant trials included nortriptyline, fluoxetinc, doxepin, trazodone, sertralinc, and paroxetine. She stated,
however, that she would become too anxious
to increase these antidepressant nlcdications
as prescribed, and dosages were never therapeutic. Methylphenidate 10 mg in the morning, and 5 mg at noon increased her energy
but was discontinued when she began to fall.
Finally, she was admitted to a local hospital.
Adnlission laboratory tests, including a serum
sodium of 137 mEq/L and a thyroid-stimulating hornlone (TSH) of 3.83 MID/mt were unremarkable. She was on the following medication regimen at the time of admission:
conjugated estrogens, 0.625 mg per day; vitamin B6 , 50 mg per day; metoclopramide, 5 mg
tid before meals for relief of nausea; L-thyroxin, 0.05 mg per day; and nefazodone, SO
mg qam and 100 mg qhs. The nefazodone was
discontinued upon her admission. Because of
her previous history of either nonresponse or
noncompliance on other tricyclic antidepressants, she was started on clomipramine, with
doses up to 75 mg per day. All other medications remained unchanged. Over the ensuing
8 days, the patient was observed by her
daughters as even more depressed, iso]ative,
and listless, now closing her eyes when they
came to visit. The daughters arranged for a
transfer and a second opinion.

Received August 1, 1996; revised November 26,1996; accepted December 5,1996. From the Stanford University
Medical Center, Stanford, CA. Address correspondence to Dr. Sommer, Director, Geriatric Psychiatry Progrnm,
Department of Psychiatry and Behavioral Sciences, Stanford University Medical Center, Stanford CA 94305-5546.
Copyright © 1997 American Association for Geriatric Psychiatry

268

VOLUME 5 • NUMBER 3 • SUMMER 1997

Sommer

On adnlission to the geriatric psychiatry
service, Mrs. A. exhibited waxing and waning
lethargy and cognitive impairment, complaining of depression and stating, 'II feel dopey,
like someone has given me something to sedate me." Her serum sodium was 122 mEq/L.
The clonlipramine was considered the likely
culprit because all other medications were either unchanged (e.g., metoclopramide for nausea) or discontinued at the other hospital
(e.g., nefazodone). Head CT scan, chest X-ray,
and Cortrosyn stimulation test were all negative; urine osmolarity was not diluted, at 582
mOsm/kg; all findings suggesting iatrogenic
SIADH. All medications, including clomipramine, were discontinued upon Mrs. A.'s admission to our hospital, and she was given intmvenous saline and furosemide. Serum
clomipramine levels were not obtained. Her
serum sodium rose slowly on this regimen. It
was noted that the patient's cognition, as measured by the Mini-Mental State-Exam (MMSE),5
improved along with her serum sodium. After
6 days on a medical service and then an additional9 days on psychiatry without intravenous sodium or diuretic, the patient'S serum
sodium rose to 135 mEqlL. Although her energy was now far improved, with no waxing
and waning of lethargy as had been seen on

adnlission, she remained depressed. She responded well to a course of electroconvulsive
therapy (Een. Three months after her hospitalization, her serum sodium remained normal,
at 136 mEq/L.

This case demonstrates that iatrogenic
SIADH, although uncommon, may result in
tenacious symptoms of lethargy and cognitive impairment with persistently low sodium values in very old patients. Mrs. A.'s
delirium and low serum sodium delayed
new treatment for her depression and prolonged her hospital stay. The long duration
of her SIADH may have been related to the
long half-life of clomipramine. Other medications given at the same time, such as conjugated estrogens, may have played a role in
the persistence of the SIADH, but this interaction has not been well studied. 6 Although tricyclic antidepressants, particularly nortriptyline and desipramine, have a
reall,lace in geriatric psychiatry,' it is im..
portant to track serum electrolytes often
when prescribing them, particularly in our
oldest patients, lest we mistake tIle delirium
ofSIADH for an exacerbation ofdepression.

References
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1994; 20:5-6
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secondary to tricyclic antidepressant. Practitioner
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