Re: I-131 Clearance Revisited

[Jocelyn Towson <jtowson@nucmed.rpa.cs.nsw.gov.au>]

>>
>>Last night at 8:00 PM, my Nuc. Med. Physician informed me that a patient
>who was administered 29.9 mCi of I-131 for Hyperthyroidism at 6:00 PM,
>vomited on the floor of her daughter's car on the way home!
>>
>>The daughter was driving on the highway at the time and could not pull over
>to get her infirm mother out of the car in time.  She attempted to clean up
>the spill on her own after she got her mother home with hot water and no
>gloves!  She said that she did not see the capsule during the clean up.  Her
>mother was apparently nervous before the administration and refused to eat
>anything before administration.  Therefore, she apparently had an empty
>stomach at administration and threw up about 45-60 minutes later.
>>

I have heard of a couple of similar anecdotes.  One involved a patient, in
an isolation room in hospital, who vomited in the toilet about 40 minutes
after a dose of 100 mCi and then cleaned up everything herself - funnily
enough,when monitored immediately afterwards,there was not a trace of I-131
in the patient or plumbing, suggesting the intact capsule had been flushed
down the loo.

 We believe I-131 therapy capsules should always be taken with food, just
like any other medication which could upset the stomach:
The dose to a region of stomach wall in prolonged contact with a therapy
capsule could be substantial if the capsule were slow to dissolve, maybe
enough to cause vomiting at any time up to 24 hours or more after the dose.
When capsules were introduced here about 6 or 7 years ago, we noticed an
increase in the number of patients complaining of nausea.  We therefore
looked at the rate of dissolution of 185MBq scan capsules in the stomach.
For resting patients with an empty stomach, capsules taken with about 200ml
of water did NOT always dissolve in 15 minutes.  In some patients the
capsules were still intact after 45 minutes, when we intervened by
providing a warm drink and some food.
It has also been reported that in some patients, I-131 capsules may not
pass rapidly to the stomach on swallowing but can be held up in the
oesophagus (J Nucl Med Technol 1997;25:55-58).


Jocelyn Towson, RSO
Dept of PET & Nuclear Medicine
Royal Prince Alfred Hospital
Camperdown, NSW 2050
Australia

tel [national]  02 9515 8011    [international] 61 2 9515 8011
fax [national]  02 9515 6381    [international] 61 2 9515 6381
email   jtowson@nucmed.rpa.cs.nsw.gov.au